---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 04/21/10: 34 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:03 AM - Re: Facet pumps: Energy vs. Flow (user9253) 2. 06:25 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) 3. 07:27 AM - Re: Re: Facet pumps: Energy vs. Flow (Robert L. Nuckolls, III) 4. 07:58 AM - Re: Re: Designing a circuit question (Robert L. Nuckolls, III) 5. 08:40 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) 6. 08:48 AM - High fuel pressure (jerry2dt@aol.com) 7. 08:49 AM - Re: Facet pumps: Energy vs. Flow (John Burnaby) 8. 08:56 AM - Future of general aviation (Robert L. Nuckolls, III) 9. 09:04 AM - Re: High fuel pressure (Robert L. Nuckolls, III) 10. 09:45 AM - Re: High fuel pressure (Doug Ilg) 11. 09:52 AM - Re: High fuel pressure (Bob Verwey) 12. 10:40 AM - Re: High fuel pressure (Sheldon Olesen) 13. 10:46 AM - Surface temperature sensor () 14. 11:41 AM - Re: Re: Designing a circuit question (Mike Welch) 15. 12:53 PM - Battery replacement in Garmin 3 pilot (mike gamble) 16. 01:12 PM - Re: Surface temperature sensor (rampil) 17. 02:04 PM - Re: Re: Surface temperature sensor () 18. 02:28 PM - Re: Accurate Altitude and Airspeed (The Kuffels) 19. 04:21 PM - Re: Surface temperature sensor (rampil) 20. 04:42 PM - Diode confusion (Lincoln Keill) 21. 05:05 PM - Re: Diode confusion (Harley) 22. 05:07 PM - Re: High fuel pressure (Tim Andres) 23. 05:42 PM - Re: Re: Designing a circuit question (Dennis & Anne Glaeser) 24. 06:33 PM - Re: Diode confusion (Robert Sultzbach) 25. 06:43 PM - Re: Diode confusion (Robert Sultzbach) 26. 06:51 PM - Re: Re: Re: Designing a circuit question (Mike Welch) 27. 08:07 PM - Re: S704-1 on Hot Side of Firewall? (Noah) 28. 08:08 PM - Re: The Miracle Whip series antennae (Speedy11@aol.com) 29. 08:15 PM - Alternator field feed - fuse vs. fusible link (Noah) 30. 08:39 PM - Circuit Diagram (rckol) 31. 09:36 PM - Re: Alternator field feed - fuse vs. fusible link () 32. 10:08 PM - Re: Future of general aviation (Paul Kuntz) 33. 10:58 PM - Re: Re: Surface temperature sensor (Robert L. Nuckolls, III) 34. 11:06 PM - Re: Re: Designing a circuit question (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 05:03:02 AM PST US Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow From: "user9253" A "tank empty switch" can be made with a magnet attached to a float inside of the tank. A magnetic reed switch on the outside of the tank will close when the magnet gets close to it. Of course this is only legal for home-built aircraft. The only thing visible on the outside of the tank will be a pair of wires with heat-shrink on the end that the covers the switch. Perhaps there are similar switches commercially available. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295073#295073 ________________________________ Message 2 _____________________________________ Time: 06:25:17 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Morning Joe, Another great idea! This list is resourceful. For my purposes, the fuel gauge I have does a good job as far as telling me when my usable fuel is out of the tank. Admittedly, there are times when four or five minutes of fuel will make a difference and if the flight is planned to land with the FAA suggested thirty minute minimum planned fuel reserve, five more minutes will make a difference to me. However, I rarely cut fuel that close so my effort is oriented more toward reducing the time the pump will be operating dry. That is why I am more interested in finding out when the pump is pumping nothing but air. So far, the best answer appears to be the optical monitoring of fuel flow. I originally thought pressure would do the trick, but as many have pointed out, there may not be enough head pressure to allow consistent measurable differences. When the idea of measuring current required by the pump surfaced, that seemed to have merit, but 'Lectric Bob seems to feel that may not be a useful measurement. I think the pressure and electron measurement solutions are worthy of some breadboard testing, but that optical monitoring of the fuel looks like a winner. Unfortunately, I now have to figure out a way of getting my local FED to agree that it is a good solution. As an aside, It appears that an earlier offering by the Pillar Point folks used a stock AN Tee for a base unit with the detector potted into the standing leg of the tee. They have now decided to manufacture their own Tee. It is my off the wall guess that I might have had better luck using the modified AN unit than I will one that is newly manufactured. Such are the vagaries of getting FAA approval for anything. I just hope that sometime in the future I will be able to afford a homebuilt instead of my present factory built steed. This is WAY off topic, but my investigation of the market shows that I can still buy an ancient factory built flying machine for less money than it would cost to get a home built machine of equivalent performance. This would be a no brainer if I could afford a homebuilt. Difficulties such as I am now encountering may get me to change my mind! Happy Skies, Old Bob In a message dated 4/21/2010 7:04:31 A.M. Central Daylight Time, fran4sew@banyanol.com writes: --> AeroElectric-List message posted by: "user9253" A "tank empty switch" can be made with a magnet attached to a float inside of the tank. A magnetic reed switch on the outside of the tank will close when the magnet gets close to it. Of course this is only legal for home-built aircraft. The only thing visible on the outside of the tank will be a pair of wires with heat-shrink on the end that the covers the switch. Perhaps there are similar switches commercially available. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295073#295073 ________________________________ Message 3 _____________________________________ Time: 07:27:25 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow At 08:08 AM 4/21/2010, you wrote: >Good Morning Joe, > >Another great idea! This list is resourceful. > >For my purposes, the fuel gauge I have does a good job as far as >telling me when my usable fuel is out of the tank. Admittedly, >there are times when four or five minutes of fuel will make a >difference and if the flight is planned to land with the FAA >suggested thirty minute minimum planned fuel reserve, five more >minutes will make a difference to me. > >However, I rarely cut fuel that close so my effort is oriented more >toward reducing the time the pump will be operating dry. That is why >I am more interested in finding out when the pump is pumping nothing >but air. So far, the best answer appears to be the optical >monitoring of fuel flow. I originally thought pressure would do the >trick, but as many have pointed out, there may not be enough head >pressure to allow consistent measurable differences. > >When the idea of measuring current required by the pump surfaced, >that seemed to have merit, but 'Lectric Bob seems to feel that may >not be a useful measurement. I've researched the evolution of the thump-thump pumps and found quite a cache of history in the patent files. A selection of examples have been posted at: http://aeroelectric.com/Mfgr_Data/Pumps/ It seems our old friend the "Bendix electric pump" is well represented and appears to have been taken over by Facet. An example of the Facet cube pump is including. All of these are "solid state" versions of the original design that simply used a set of contacts to control the solenoid coil current to re-stroke the pump. I was surprised to find that "solid state" went back so far. The 1968 Bendix patent still has the mechanical switch contacts but uses transistors to buffer the coil current so that the contacts don't erode electrically. Later versions use hall effect devices to sense plunger position. The surprise was to find a couple of designs that used a free-running oscillator (555 timer) to simple pulse the solenoid periodically. No plunger position sensing at all. It's possible that some versions will present a unique current signature that could be used to detect when the pump was running unloaded but you'd have to do some all-conditions, all-variables studies to make sure that your sensing scheme did not risk false indications. >I think the pressure and electron measurement solutions are worthy >of some breadboard testing, but that optical monitoring of the fuel >looks like a winner. Back in the summer of 08 we had some discussion here on the list about optical liquid level sensors. These have a rich history of practical application in automotive applications dating back to the 1950's. Modern incarnations include a series of devices I was responsible for at Electro-Mech in the 80's that have been built by the thousands and incorporated into dozens of applications on Beech/RAC/Hawker-Beech products. Here's a collection of pictures that show features and products in the optical liquid level sensors technology: http://aeroelectric.com/Pictures/Fuel_Level/ Gem Sensors is a good place to start for commercial off-the-shelf devices. They're quite rugged and entirely suited to the task. http://www.gemssensors.com/content.aspx?id=282 > Unfortunately, I now have to figure out a way of getting my local > FED to agree that it is a good solution. You're not proposing to do anything new, daring and fraught with risk. Successful integration of these devices into a tank have only to do with mundane issues of craftsmanship that go to keeping the fuel inside the pipes . . . i.e. leaks. The neat thing about sensing absolute level in the tank is the "dipstick" accuracy of the value. There are no variables of calibration associated with setting trip points to light indicators from fuel level transmitters, etc. I could see a 337 mod to add the sensor to the side of a tank. It's an ADDITION that is an operating convenience and has no effect on the basis for certification for the original TC. Risks are limited to issues of good shop practice and craftsmanship. Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:58:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: Designing a circuit question Hi Bob, and everyone else following this thread... I have an even simpler solution, possibly costing significantly less, using the hotly debated poly-fuse. Simply put a 6A or 7A one in series with the motor, with an LED+resistor across it. When the fuse trips, the LED is energised... In it's normal state, all the current travels through the low impedance fuse, and 'none' through the LED+resistor path. No heatsink required! However, there is the problem of securing everything and making sure vibration doesn't age the soldered joints prematurely. I considered this. This is the control philosophy for most cars on the electric window-risers. It's certainly simple and reliable. They are relatively slow acting devices and it would take some experimentation to get the right device. Also, once they've tripped, it may take 10 seconds or more for them to cool off enough to reset. So once the light comes on, you would have to wait for sufficient cooling to come off the stop. But if that operating mode meets design goals, it's certainly an option. Does the current limiting characteristic you mention literally limit the current to the pitch motor? My guess is it does (at least somewhat), which is why the N-fet becomes a cabin heater. But it's a heater only while you are in the current limited mode. i.e. against the stop and the light is lit. Only a second or so at a time (reaction time to release the switch after the light comes on). I'm thinking that the electrical paths from the switch to the N-fet, and path from the N-fet to the ALSRJ resistor to ground need to be capable of 10A, but the other wiring will see much less. How would I 'adjust for desired limit' on the ALSRJ resistor to go up to say 8A? How did you calculate or estimate that value? How sensitive would you anticipate that to be? The current limit calibration is a function of voltage drop across the low value resistor and the base-emitter turn-on voltage for the clamp transistor. Assuming 0.6 volts turn-on and 0.1 ohms, we get about 6 amps. I would 'trim' the set point to higher values by paralleling the 0.1 ohm resistor with another, higher value. The reason I ask is that the load on the motor does increase as the pitch on the blades approach the high (and low) pitch limits, before the mechanical stop is reached. The mechanism is literally twisting composite blades, they don't rotate in bearings like 'regular' adjustable blades. I may have to adjust the current limit to be sure I can get the blades close enough to the pitch limits for my purposes. My rough measurement of current (reading a clamp on meter) indicates a pretty good knee in the curve at around 8A. 6A may be close enough, only testing will tell. Exactly. Adding a 0.5 ohm resistor in parallel would raise the set point to abut 7.2 amps. Adding another .5 ohm raises it to 8.4 amsp, etc. Finally, how would you compare this circuit to the reed switch approach that Joe Gores proposed, from a standpoint of repeatability of sensing the target amperage, and the ability to make adjustments to get to the desired target (number of winds and wire size selection)? The reed switch would only light the light, it would not eliminate using the "breaker-trip" as the ultimate limit switch. In the stone-simple category of solutions, the polyswitch suggestion has some merit. Related question. How is the amount of heat sink area calculated? I assume it is based on the amount of energy converted to heat. Where can I find the info to determine what size heat sink is required. Does the electrically insulating material also thermally insulate the component and affect the design of the heat sink? Heat sinking is an interesting and not really complicated discipline. It comes with two primary design goals to consider. They might be characterized as the "marathon" and "100-yard dash" modes for thermal management. A heat sink's ability to keep a semiconductor cool is a combination of thermal mass and surface area available to reject heat. In the case of CONTINUOUS duty operation like the linear dimmer modules, surface area and air flow are the driving considerations. In our intermittent duty application (1 second at each end of stroke), we can use a heat sink that is horribly undersized for continuous duty as long as total thermal mass is sufficient to keep the transistor junction from fusing in the few seconds per operation and sufficiently space to allow cooling for the next cycle. I didn't do a calculation for the suggestion that was mostly an experience-based recommendation. There's a lot of data available on the 'net that speaks to continuous duty heat sink sizing and the insulating, thermally conducting washers used to electrically isolate the device from the heat sink. Intermittent duty sizing is not so common although it's easily estimated. It's a thermal rate-of-rise study that accounts for junction to sink thermal resistance + thermal inertia of the heatsink where we consider the specific heat of the material and it's total mass. I think I've got some words that discuss that process somewhere, I'll dig around. In any case, for this application, we don't need to design a heat-sink that allows the transistor to operate in an extended "cabin heater" mode. Bob . . . ________________________________ Message 5 _____________________________________ Time: 08:40:25 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Morning 'Lectric Bob, Thanks for the update. Your answer coordinates well with my thoughts. If I could find a certificated optical flow monitoring device, I would install it using part 43 as data. No sweat at all! While I do not have any desire to install more sensors in my fuel tanks, I agree that Part 43 substantiation should work there. Thanks again to all who have responded. It really helps flesh out the answer. Happy Skies, Old Bob AKA Bob Siegfried Bob's Aircraft Service Downers Grove, IL Stearman N3977A (and others) In a message dated 4/21/2010 9:29:14 A.M. Central Daylight Time, nuckolls.bob@aeroelectric.com writes: At 08:08 AM 4/21/2010, you wrote: Good Morning Joe, Another great idea! This list is resourceful. For my purposes, the fuel gauge I have does a good job as far as telling me when my usable fuel is out of the tank. Admittedly, there are times when four or five minutes of fuel will make a difference and if the flight is planned to land with the FAA suggested thirty minute minimum planned fuel reserve, five more minutes will make a difference to me. However, I rarely cut fuel that close so my effort is oriented more toward reducing the time the pump will be operating dry. That is why I am more interested in finding out when the pump is pumping nothing but air. So far, the best answer appears to be the optical monitoring of fuel flow. I originally thought pressure would do the trick, but as many have pointed out, there may not be enough head pressure to allow consistent measurable differences. When the idea of measuring current required by the pump surfaced, that seemed to have merit, but 'Lectric Bob seems to feel that may not be a useful measurement. I've researched the evolution of the thump-thump pumps and found quite a cache of history in the patent files. A selection of examples have been posted at: _http://aeroelectric.com/Mfgr_Data/Pumps/ _ (http://aeroelectric.com/Mfgr_Data/Pumps/) It seems our old friend the "Bendix electric pump" is well represented and appears to have been taken over by Facet. An example of the Facet cube pump is including. All of these are "solid state" versions of the original design that simply used a set of contacts to control the solenoid coil current to re-stroke the pump. I was surprised to find that "solid state" went back so far. The 1968 Bendix patent still has the mechanical switch contacts but uses transistors to buffer the coil current so that the contacts don't erode electrically. Later versions use hall effect devices to sense plunger position. The surprise was to find a couple of designs that used a free-running oscillator (555 timer) to simple pulse the solenoid periodically. No plunger position sensing at all. It's possible that some versions will present a unique current signature that could be used to detect when the pump was running unloaded but you'd have to do some all-conditions, all-variables studies to make sure that your sensing scheme did not risk false indications. I think the pressure and electron measurement solutions are worthy of some breadboard testing, but that optical monitoring of the fuel looks like a winner. Back in the summer of 08 we had some discussion here on the list about optical liquid level sensors. These have a rich history of practical application in automotive applications dating back to the 1950's. Modern incarnations include a series of devices I was responsible for at Electro-Mech in the 80's that have been built by the thousands and incorporated into dozens of applications on Beech/RAC/Hawker-Beech products. Here's a collection of pictures that show features and products in the optical liquid level sensors technology: _http://aeroelectric.com/Pictures/Fuel_Level/ _ (http://aeroelectric.com/Pictures/Fuel_Level/) Gem Sensors is a good place to start for commercial off-the-shelf devices. They're quite rugged and entirely suited to the task. _http://www.gemssensors.com/content.aspx?id=282_ (http://www.gemssensors.com/content.aspx?id=282) Unfortunately, I now have to figure out a way of getting my local FED to agree that it is a good solution. You're not proposing to do anything new, daring and fraught with risk. Successful integration of these devices into a tank have only to do with mundane issues of craftsmanship that go to keeping the fuel inside the pipes . . . i.e. leaks. The neat thing about sensing absolute level in the tank is the "dipstick" accuracy of the value. There are no variables of calibration associated with setting trip points to light indicators from fuel level transmitters, etc. I could see a 337 mod to add the sensor to the side of a tank. It's an ADDITION that is an operating convenience and has no effect on the basis for certification for the original TC. Risks are limited to issues of good shop practice and craftsmanship. Bob . . . ________________________________ Message 6 _____________________________________ Time: 08:48:57 AM PST US Subject: AeroElectric-List: High fuel pressure From: jerry2dt@aol.com Folks, Re-posting from VAF, no joy over there but hope there might be someone her e with an idea... Normally my fuel pressure with the mech pump runs 30-35 psi and with the boost on goes to 40-ish. Suddenly the other day I got a warning on my GRT EFIS when the pressure went to 190 psi and that has continued since, so am very reluctant to fly until this is sorted out. No engine stumbles or anything otherwise abnormal. Fuel flow is fine. This is an injected Bendix system on an IO-360 with 160 trouble free hours since new. I've never heard of this before, so if anyone here has ideas, advice, answ ers, please respond. BTW, I love that the EFIS picked this out for me and sent up the flag, ver y handy. Thanks all, Jerry Cochran -----Original Message----- From: AeroElectric-List Digest Server Sent: Tue, Apr 20, 2010 11:55 pm Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10 * ======================== ======================== = Online Versions of Today's List Digest Archive ======================== ======================== = Today's complete AeroElectric-List Digest can also be found in either of the two Web Links listed below. The .html file includes the Digest formatted in HTML for viewing with a web browser and features Hyperlinked Indexes and Message Navigation. The .txt file includes the plain ASCII version of the AeroElectric-List Digest and can be viewed with a generic text edit or such as Notepad or with a web browser. HTML Version: http://www.matronics.com/digest/digestview.php?Style=82701&View=ht ml&Chapter 10-04-20&Archive=AeroElectric Text Version: http://www.matronics.com/digest/digestview.php?Style=82701&View=tx t&Chapter 10-04-20&Archive=AeroElectric ======================== ======================= EMail Version of Today's List Digest Archive ======================== ======================= ---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 04/20/10: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd) 2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil) 3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) 4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley) 5. 07:51 AM - Re: (BobsV35B@aol.com) 6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com ) 7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch) 8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com ) 9. 01:53 PM - Re: switch breaker on ALT field (rckol) 10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah) 11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckoll s, III) 12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckoll s, III) ________________________________ Message 1 _____________________________ ________ Time: 04:40:20 AM PST US Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow From: Bill Boyd How about some filtering on the "input" line of the ammeter? If we're looking at constant-amplitude square wave current pulses of varying frequency, a capacitive filter to perform an "integral" function might giv e you an average-current-over-time measurement that closely matches the frequency and therefore the load on the pump. In practice, I am not sure from listening to my Facet pump all these years how much the frequency changes as a function of load. There is a sound change as it self-primes when I first hit it before engine-start. Just a thought. I had to do the pneumatic equivalent (expansion chamber plus input restrictor) to keep my manifold pressure digital readout from jumping all around in an un-readable fashion. A little RC pi or L network might do what you need. Bill B. On Mon, Apr 19, 2010 at 9:56 PM, Charlie England wrote: > ceengland@bellsouth.net> > > Certificated. Bummer. > > If you think you can legally use current sensing, have you tried a > restricter in the pump's output to see if it will raise the current enou gh > to be measurable vs the no-flow state? > > On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote: > >> Good Morning Charlie, >> Those units by Pillar Point Electronics look very promising. As I said a >> couple of messages back, I need something that can be used on a normall y >> certificated aircraft. Not sure about the PPE product, but I am checkin g >> into it. >> Thanks for the comment. >> Happy Skies, >> Old Bob >> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, >> ceengland@bellsouth.net writes: >> >> >> >> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: >> > >> > To me, they look and sound just like the ones that were used >> > on those Ford gasoline fired heaters back in the thirties. But >> my memory >> > could be fooling me. >> > >> > Those were probably the Stewart Warner or Bendix pumps. >> > Whadda Ya Think? >> > >> > If so. does that mean I need to monitor the frequency some >> > how? >> > >> > This is getting complicated,. No wonder nobody does it! >> > >> > Happy Skies, >> > >> > Old Bob >> > >> > I am not sure of the application here, but I >> > believe that there should be a significant pressure drop on the >> output of >> > the pump, when there is no longer any fuel. This being the >> case, perhaps >> > you could use a pressure switch, similar to what is used to >> monitor engine >> > oil pressure and turn on the hobbs meter, on some aircraft. You >> would need >> > to check the pressure differential between pumping fuel and >> empty tank >> > pumping, and use a switch midway between. This would be a >> normally closed >> > switch which would open when there is fuel flow and close, to >> turn on the >> > light when there is no more fuel to pump. >> > >> > Not sure if this is a viable option for your >> > application, but might work, and is very simple. (I especially li ke >> > simple:-) >> > >> > Roger >> > >> If you're using it as a transfer pump, there won't be a lot of >> pressure >> since it will be just the 'head' from one tank to the other. Often no >> more than a few inches of rise, plus the resistance of the tubing. >> >> How about one of the sensing devices using light to detect the >> presence >> of liquid? I bought a couple several years ago, intending to use >> them to >> monitor end-of-transfer from my aux tanks, then forgot to install >> them.... They mount in a single hole & have a cone shaped plexi >> tip. An >> LED shines out through the plexi; presence/absence of liquid >> changes the >> light reflected back into the photocell in the same housing, changin g >> the state of the sense line. >> >> If that interests you, I'll try to locate the name of the device & a >> source for you. >> >> Charlie >> >> * >> >> >> * >> > > ________________________________ Message 2 _____________________________ ________ Time: 05:43:01 AM PST US Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow From: "rampil" Good engineering principles favor measuring the actual parameter you want, rather than a surrogate, especially when there is no reliable one-to-one mapping of one to the other. In the case of current draw, for example, overheating the coil or dirt in the mechanism will probably change the current draw Pressure downstream would depend on where the fill hose enters the downstream tank, if at the bottom, or at a positive hydrostatic head, the pressure downstream of the pump will stay positive while there is fuel in the tank. What about measuring fuel level in the feeding tank, is not that what you really want to make a decision with? When it reads zero, stop pumping? -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=294942#294942 ________________________________ Message 3 _____________________________ ________ Time: 05:48:55 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow Good Morning Bill, Wow! It appears that any suitable current measuring device will be a lot more complex than my feeble brain can comprehend. Thanks to you and all the others that have contributed to my on going education. In any case, it does seem that a few breadboard experiments are in order. Happy Skies, Old Bob In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time, sportav8r@gmail.com writes: How about some filtering on the "input" line of the ammeter? If we're looking at constant-amplitude square wave current pulses of varying freque ncy, a capacitive filter to perform an "integral" function might give you an average-current-over-time measurement that closely matches the frequency and therefore the load on the pump. In practice, I am not sure from listenin g to my Facet pump all these years how much the frequency changes as a function of load. There is a sound change as it self-primes when I first hit it before engine-start. Just a thought. I had to do the pneumatic equivalent (expansion chamber plus input restrictor) to keep my manifold pressure digital readout from jumping all around in an un-readable fashion. A little RC pi or L network might do what you need. Bill B. On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net _ (mailto:ceengland@bellsouth.net) > wrote: <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > Certificated. Bummer. If you think you can legally use current sensing, have you tried a restricter in the pump's output to see if it will raise the current enoug h to be measurable vs the no-flow state? On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote : Good Morning Charlie, Those units by Pillar Point Electronics look very promising. As I said a couple of messages back, I need something that can be used on a normally certificated aircraft. Not sure about the PPE product, but I am checking into it. Thanks for the comment. Happy Skies, Old Bob In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, _ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes: <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: > > To me, they look and sound just like the ones that were used > on those Ford gasoline fired heaters back in the thirties. But my memory > could be fooling me. > > Those were probably the Stewart Warner or Bendix pumps. > Whadda Ya Think? > > If so. does that mean I need to monitor the frequency some > how? > > This is getting complicated,. No wonder nobody does it! > > Happy Skies, > > Old Bob > > I am not sure of the application here, but I > believe that there should be a significant pressure drop on the output of > the pump, when there is no longer any fuel. This being the case, perhaps > you could use a pressure switch, similar to what is used to monitor engine > oil pressure and turn on the hobbs meter, on some aircraft. You would need > to check the pressure differential between pumping fuel and empty tank > pumping, and use a switch midway between. This would be a normally closed > switch which would open when there is fuel flow and close, to turn on the > light when there is no more fuel to pump. > > Not sure if this is a viable option for your > application, but might work, and is very simple. (I especially like > simple:-) > > Roger > If you're using it as a transfer pump, there won't be a lot of pressure since it will be just the 'head' from one tank to the other. Often no more than a few inches of rise, plus the resistance of the tubing. How about one of the sensing devices using light to detect the presence of liquid? I bought a couple several years ago, intending to use them to monitor end-of-transfer from my aux tanks, then forgot to install them.... They mount in a single hole & have a cone shaped plexi tip. An LED shines out through the plexi; presence/absence of liquid changes the light reflected back into the photocell in the same housing, changing the state of the sense line. If that interests you, I'll try to locate the name of the device & a source for you. Charlie ________________________________ Message 4 _____________________________ ________ Time: 06:09:04 AM PST US Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow From: "Jon Finley" =0AI find this discussion very interesting and hope for an inexpensive solu tion. I really like that Pillar Point flow detector but the price is more than I'd like to spend.=0A =0AJust to add some data points.... In my case, I know the fuel level in the tank but I wish to know when fuel stops being delivered to that tank so alternate plans can be made. So, a "fuel is not f lowing" indicator would add a level of comfort (would be "nice" but certai n ly not mandatory since I am currently flying without this).=0A =0AMore spec ifically, I have a large main tank from which fuel is pumped into the head e r. The header is about 5 gallons (one hour of flight time). I typically l eave my transfer pump on all the time. If it were to stop and I didn't no t ice (which is likely), I have a warning light that will come on at about 2. 5-3 gallons. That leaves me with about 30 minutes to figure out what to do . If I had known immediately, I would have had 60 minutes. Of course, I h ave a backup fuel pump which I would immediately switch on. However; it ca n take some time before seeing the fuel level start to rise. When dealing w ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a bi g deal (at least in terms of my stress level - FYI, I live out west were ai r ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0A N314JF - Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www .fi nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message----- =0AFrom: " rampil" =0ASent: Tuesday, April 20, 2010 6:41am= 0ATo: aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet pu =0A=0AGood engineering principles favor measuri ng th e actual parameter=0Ayou want, rather than a surrogate, especially when the re is no=0Areliable one-to-one mapping of one to the other.=0A=0AIn the cas e of current draw, for example, overheating the coil or dirt=0Ain the me cha nism will probably change the current draw=0APressure downstream would depe nd on where the fill hose enters the =0Adownstream tank, if at the botto m, or at a positive hydrostatic head, the =0Apressure downstream of the pum p w ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about measur ing fuel level in the feeding tank, is not that what you=0Areally want to m ake a decision with? When it reads zero, stop pumping?=0A=0A-------- =0AIra N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp: //forums.matron ================0A=0A=0A=0A ________________________________ Message 5 _____________________________ ________ Time: 07:51:11 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Test --- Do Not Archive In a message dated ________________________________ Message 6 _____________________________ ________ Time: 07:58:18 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Morning Ira, I have what I consider to be relatively good fuel gauges in the tanks, but find that there is at least a ten to fifteen minute window between where the gauge says empty and it actually will be dry. I do not wish to turn the pump off too soon and have fuel in the tank that has not been used and I do not like to run the pump when it is not actually pumping fuel. It would be very nice to be able to verify the accuracy of the fuel gauge by noting when the pump stops pumping fuel rather than running the pump while dry for possibly an extra ten to fifteen minutes every time I utili ze the auxiliary fuel tank. I do have excellent fuel use measuring capability and what I do now is not e the fuel burned number when I turn on the pump and shut it off when the amount of fuel known to be in the tank has been burned. Nevertheless, it would be nice to know within seconds when the tank has ru n dry so that the pump could be turned off. I really would rather not be running the pump when it is not pumping fuel .. Happy Skies, Old Bob In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time, ira.rampil@gmail.com writes: --> AeroElectric-List message posted by: "rampil" Good engineering principles favor measuring the actual parameter you want, rather than a surrogate, especially when there is no reliable one-to-one mapping of one to the other. In the case of current draw, for example, overheating the coil or dirt in the mechanism will probably change the current draw Pressure downstream would depend on where the fill hose enters the downstream tank, if at the bottom, or at a positive hydrostatic head, the pressure downstream of the pump will stay positive while there is fuel in the tank. What about measuring fuel level in the feeding tank, is not that what you really want to make a decision with? When it reads zero, stop pumping? -------- Ira N224XS ________________________________ Message 7 _____________________________ ________ Time: 10:35:34 AM PST US From: Mike Welch Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Bob=2C Pardon me for butting in=2C but from my experience with certificated airp lanes=2C it is virtually impossible to get a field approval like you're aft er. I used to have a 1961 Cessna 172=2C with an O-300 Continental. On tho se hot mid-summer California days (100+)=2C my oil temps got well into the red on climbout!! I checked the accuracy of the gauge=2C and it was correc t! Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn' t c ome with one=2C but I could get a later model 172 oil cooler to fit. I sen t off my Form 337 to the local FSDO=2C and their first reaction was "NO! " Their attitude was "if it didn't come with one=2C it doesn't need one!!" I was irritated (to say the least)=2C and requested an appeal. They fina lly relented and said it would be okay. For crying out loud =2C it was jus t an oil cooler!! (all certified parts=2C too) My opinion is=3B there ain't no way you can legally add any kind of pe rma nent parts to modify to your fuel pump=2C fuel lines=2C or anything el se=2C on a certificated airplane=2C without that approved 337. Just my opinion................. Mike Welch From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Morning Ira=2C I have what I consider to be relatively good fuel gauges in the tanks=2C bu t find that there is at least a ten to fifteen minute window between where the gauge says empty and it actually will be dry. I do not wish to turn th e pump off too soon and have fuel in the tank that has not been used and I d o not like to run the pump when it is not actually pumping fuel. It would be very nice to be able to verify the accuracy of the fuel gauge b y noting when the pump stops pumping fuel rather than running the pump whi l e dry for possibly an extra ten to fifteen minutes every time I utilize th e auxiliary fuel tank. I do have excellent fuel use measuring capability and what I do now is not e the fuel burned number when I turn on the pump and shut it off when the am ount of fuel known to be in the tank has been burned. Nevertheless=2C it would be nice to know within seconds when the tank ha s r un dry so that the pump could be turned off. I really would rather not be running the pump when it is not pumping fuel. Happy Skies=2C Old Bob In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.r amp il@gmail.com writes: Good engineering principles favor measuring the actual parameter you want=2C rather than a surrogate=2C especially when there is no reliable one-to-one mapping of one to the other. In the case of current draw=2C for example=2C overheating the coil or dirt in the mechanism will probably change the current draw Pressure downstream would depend on where the fill hose enters the downstream tank=2C if at the bottom=2C or at a positive hydrostatic he ad=2C the pressure downstream of the pump will stay positive while there is fuel in the tank. What about measuring fuel level in the feeding tank=2C is not that what you really want to make a decision with? When it reads zero=2C stop pumping? -------- Ira N224XS _________________________________________________________________ Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL: O N:WL:en-US:WM_HMP:042010_2 ________________________________ Message 8 _____________________________ ________ Time: 11:05:32 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Afternoon Mike, Believe it or not I do understand your frustration and the problems that are faced when dealing with the FAA. It is my opinion that the vast majority of the folks at FAA want to do a good job, but are so hamstrung with regulations and paper work that it is easier to just say no. However, I have had fairly good luck getting local approvals from my supervising FSDO. As I think we can all agree, each FSDO is a kingdom unto itself and what is easy to get approved at one office may be impossible at another. Nevertheless, I have gotten several local approvals here locally. I do ho ld an A&P with Inspection Authorization. It does help me know who I should present the data to and how the presentation should be made. In general, if we can think of a way to add something that has no chance of interfering with required equipment, the local approval has a better chance of being approved. Once again, the FAA has no obligation to ever issue a local approval. In fact, if an individual inspector does issue the approval, he is doing it on his own knowledge and is personally responsible for what happens. In many ways it is surprising that any FAA inspector ever issues a local approval . He/she has no obligation to do so. It is just a privilege he has been accorded. Failure to do so does not hurt his career at all, but making a dumb approval could end his career. Happy Skies, Old Bob In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time, mdnanwelch7@hotmail.com writes: Bob, Pardon me for butting in, but from my experience with certificated airplanes, it is virtually impossible to get a field approval like you're after. I used to have a 1961 Cessna 172, with an O-300 Continental. On those ho t mid-summer California days (100+), my oil temps got well into the red on climbout!! I checked the accuracy of the gauge, and it was correct! Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't com e with one, but I could get a later model 172 oil cooler to fit. I sent of f my Form 337 to the local FSDO, and their first reaction was "NO!" Their attitude was "if it didn't come with one, it doesn't need one!!" I was irritated (to say the least), and requested an appeal. They finall y relented and said it would be okay. For crying out loud , it was just an oil cooler!! (all certified parts, too) My opinion is; there ain't no way you can legally add any kind of permanent parts to modify to your fuel pump, fuel lines, or anything else , on a certificated airplane, without that approved 337. Just my opinion................. Mike Welch ________________________________ Message 9 _____________________________ ________ Time: 01:53:26 PM PST US Subject: AeroElectric-List: Re: switch breaker on ALT field From: "rckol" Switch breakers will function for this application. I have read conflicting reports about the long term reliability of these. Some folks end up tearing them out because they don't hold up and others have no trouble with them. Sorry, I don't have any brand specific recommendations. I am not going to use them. Dick -------- rck Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295024#295024 ________________________________ Message 10 ____________________________ ________ Time: 03:38:33 PM PST US Subject: AeroElectric-List: S704-1 on Hot Side of Firewall? From: "Noah" I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco T9A with an operating temp limit of 85C (185F). This seems a bit low for moun ting in the engine compartment on the firewall. where I had been planning to mo unt it. I called B&C to ask them if they recommended mounting these in the en gine compartment and the gentleman I spoke with was not sure - he recommended a post here. Anybody know what the firewall temps can climb to?? Anybody mounted one of these firewall forward in an RV and had problems? Or had it last 2000 hours wit hout issue?? -------- Highest Regards, Noah Forden RV-7A Rhode Island Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295030#295030 ________________________________ Message 11 ____________________________ ________ Time: 08:30:35 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall? At 05:36 PM 4/20/2010, you wrote: > >I requested the spec sheet for the S704-1 relay from B&C, and it is >a Tyco T9A with an operating temp limit of 85C (185F). This seems a >bit low for mounting in the engine compartment on the firewall. >where I had been planning to mount it. I called B&C to ask them if >they recommended mounting these in the engine compartment and the >gentleman I spoke with was not sure - he recommended a post here. > >Anybody know what the firewall temps can climb to?? Anybody mounted >one of these firewall forward in an RV and had problems? Or had it >last 2000 hours without issue?? It will be fine. These devices and their close cousins are used under the hood of motor vehicles and they're fine. The various companies I've worked for have done numerous studies of temperature under the cowl and found that nothing gets really all that hot as long as it's not exposed to direct infra-red radiation from stacks (particularly turbochargers). I've seen some RG battery cases melted because they were too close to exhaust pipes. Bob . . . ________________________________ Message 12 ____________________________ ________ Time: 08:36:06 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: switch breaker on ALT field At 03:50 PM 4/20/2010, you wrote: > >Switch breakers will function for this application. > >I have read conflicting reports about the long term reliability of >these. Some folks end up tearing them out because they don't hold >up and others have no trouble with them. Sorry, I don't have any >brand specific recommendations. I am not going to use them. The mil-qualified sw/breakers are fine. Actually, the P&B W31 series are reasonably decent too. There's about 80K in service in Bonanzas and Barons since way back when . . . and yes, a few have failed in a way that put smoke in the cockpit . . . but those were the 30A devices that control electric prop de-ice. Obviously, you can't get the features in single switches of any kind that are offered in the progressive- transfer 2-pole toggles (2-10, 2-50, 2-70) but if your design goals don't require this feature, then the single switches will do. Now, having said that, I'm not sure I'd recommend the W31 used upstream of a crowbar ov protection system that I designed. I've not studied the trip dynamics of this device in that application. The miniature TI/Klixon style breakers have been paired with our crowbar ov systems by the thousands with good service histories. Bob . . . ======================== =========== ======================== =========== ======================== =========== ======================== =========== ________________________________ Message 7 _____________________________________ Time: 08:49:15 AM PST US From: "John Burnaby" Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow Check out Gems Sensors and this optical sensor: http://www.gemssensors.com/content.aspx?id=5432 I got one off of Ebay for $5. When it "sees" fluid, it will sink 40ma to drive a relay coil that closes the circuit on the Facet. I'm using this same setup to power a Facet transfer pump. SPST switch to power Optical sensor switch, to power relay, to power FACET and LED "On". ________________________________ Message 8 _____________________________________ Time: 08:56:00 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Future of general aviation At 12:29 PM 4/20/2010, you wrote: Bob, Pardon me for butting in, but from my experience with certificated airplanes, it is virtually impossible to get a field approval like you're after. I used to have a 1961 Cessna 172, with an O-300 Continental. On those hot mid-summer California days (100+), my oil temps got well into the red on climbout!! I checked the accuracy of the gauge, and it was correct! Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't come with one, but I could get a later model 172 oil cooler to fit. I sent off my Form 337 to the local FSDO, and their first reaction was "NO!" Their attitude was "if it didn't come with one, it doesn't need one!!" I was irritated (to say the least), and requested an appeal. They finally relented and said it would be okay. For crying out loud , it was just an oil cooler!! (all certified parts, too) My opinion is; there ain't no way you can legally add any kind of permanent parts to modify to your fuel pump, fuel lines, or anything else, on a certificated airplane, without that approved 337. Just my opinion................. An opinion not without foundation. Without telling stories on anyone, I can share that I attended a meeting yesterday. This was a gathering of technically competent, talented integrators of simple-ideas into elegant solutions. They were stampeded into a "solution" the crippled the capability of perfectly good system just to cover a flight condition that was easily managed . . . all in the name of achieving "FAA certification". I pissed off some of the attendees . . . may have lost future business for that customer. Present trends plotted into the future do not bode well for our beloved airplanes and the people who design, build and fly them. We have ever increasing numbers of people who do not design, build and fly demanding to run the show . . . all in the cause of "making airplanes safer". Bob . . . ________________________________ Message 9 _____________________________________ Time: 09:04:37 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: High fuel pressure At 10:46 AM 4/21/2010, you wrote: > >Folks, > >Re-posting from VAF, no joy over there but hope there might be >someone here with an idea... > >Normally my fuel pressure with the mech pump runs 30-35 psi and with >the boost on goes to 40-ish. Suddenly the other day I got a warning >on my GRT EFIS when the pressure went to 190 psi and that has >continued since, so am very reluctant to fly until this is sorted >out. No engine stumbles or anything otherwise abnormal. Fuel flow is fine. > >This is an injected Bendix system on an IO-360 with 160 trouble free >hours since new. > >I've never heard of this before, so if anyone here has ideas, >advice, answers, please respond. > >BTW, I love that the EFIS picked this out for me and sent up the >flag, very handy. Is the pump really capable of that kind of pressure? A failure of a relief valve might account for an unexpected rise in pressure but I'd be suspicious of the EFIS pressure transducer too. It's MUCH more complicated than that spring-loaded relief valve. Double check with a simple dial-gauge. Bob . . . ________________________________ Message 10 ____________________________________ Time: 09:45:23 AM PST US From: Doug Ilg Subject: Re: AeroElectric-List: High fuel pressure Have you (re-)checked the accuracy of the sensor?- Did you accidentally c hange a calibration factor in the EFIS?- That's a HUGE jump.=0A-=0ADoug Ilg=0AGrumman Tiger N74818, College Park-Airport (KCGS), Maryland=0AChal lenger II LSS LW (N641LG-reserved)-- kit underway at Laurel Suburban (W 18)=0A=0A-=0A=0A=0A>=0A>From: "jerry2dt@aol.com" =0A>To : aeroelectric-list@matronics.com=0A>Sent: Wed, April 21, 2010 11:46:44 AM =0A>Subject: AeroElectric-List: High fuel pressure=0A>=0A>=0A______________ __________________=0A=0A>Folks,=0A>=0A>Re-posting from VAF, no joy over the re but hope there might be someone here with an idea...=0A>=0A>Normally my fuel pressure with the mech pump runs 30-35 psi and with the boost on goes to 40-ish. Suddenly the other day I got a warning on my GRT EFIS when the p ressure went to 190 psi and that has continued since, so am very reluctant to fly until this is sorted out. No engine stumbles or anything otherwise a bnormal. Fuel flow is fine. =0A> ________________________________ Message 11 ____________________________________ Time: 09:52:48 AM PST US Subject: Re: AeroElectric-List: High fuel pressure From: Bob Verwey Can only be a sender unit problem IMHO...pump would not be able to make this kind of pressure. regards Bob Verwey On 21 April 2010 17:46, wrote: > ------------------------------ > Folks, > > Re-posting from VAF, no joy over there but hope there might be someone here > with an idea... > > Normally my fuel pressure with the mech pump runs 30-35 psi and with the > boost on goes to 40-ish. Suddenly the other day I got a warning on my GRT > EFIS when the pressure went to 190 psi and that has continued since, so am > very reluctant to fly until this is sorted out. No engine stumbles or > anything otherwise abnormal. Fuel flow is fine. > > This is an injected Bendix system on an IO-360 with 160 trouble free hours > since new. > > I've never heard of this before, so if anyone here has ideas, advice, > answers, please respond. > > BTW, I love that the EFIS picked this out for me and sent up the flag, very > handy. > > Thanks all, > > Jerry Cochran > > > -----Original Message----- > From: AeroElectric-List Digest Server > To: AeroElectric-List Digest List > Sent: Tue, Apr 20, 2010 11:55 pm > Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10 > > * > > > ================================================= > > Online Versions of Today's List Digest Archive > > ================================================= > > > Today's complete AeroElectric-List Digest can also be found in either of the > > two Web Links listed below. The .html file includes the Digest formatted > > in HTML for viewing with a web browser and features Hyperlinked Indexes > > and Message Navigation. The .txt file includes the plain ASCII version > > of the AeroElectric-List Digest and can be viewed with a generic text editor > > such as Notepad or with a web browser. > > > HTML Version: > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter 10-04-20&Archive=AeroElectric > > > Text Version: > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 10-04-20&Archive=AeroElectric > > > =============================================== > > EMail Version of Today's List Digest Archive > > =============================================== > > > ---------------------------------------------------------- > > AeroElectric-List Digest Archive > > --- > > Total Messages Posted Tue 04/20/10: 12 > > ---------------------------------------------------------- > > > Today's Message Index: > > ---------------------- > > > 1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd) > > 2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil) > > 3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) > > 4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley) > > 5. 07:51 AM - Re: (BobsV35B@aol.com) > > 6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) > > 7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch) > > 8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) > > 9. 01:53 PM - Re: switch breaker on ALT field (rckol) > > 10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah) > > 11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckolls, > > III) > > 12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckolls, > > III) > > > ________________________________ Message 1 _____________________________________ > > > Time: 04:40:20 AM PST US > > Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow > > From: Bill Boyd > > > How about some filtering on the "input" line of the ammeter? If we're > > looking at constant-amplitude square wave current pulses of varying > > frequency, a capacitive filter to perform an "integral" function might give > > you an average-current-over-time measurement that closely matches the > > frequency and therefore the load on the pump. In practice, I am not sure > > from listening to my Facet pump all these years how much the frequency > > changes as a function of load. There is a sound change as it self-primes > > when I first hit it before engine-start. > > > Just a thought. I had to do the pneumatic equivalent (expansion chamber > > plus input restrictor) to keep my manifold pressure digital readout from > > jumping all around in an un-readable fashion. A little RC pi or L network > > might do what you need. > > > Bill B. > > > On Mon, Apr 19, 2010 at 9:56 PM, Charlie England wrote: > > > > ceengland@bellsouth.net> > > > > > > Certificated. Bummer. > > > > > > If you think you can legally use current sensing, have you tried a > > > restricter in the pump's output to see if it will raise the current enough > > > to be measurable vs the no-flow state? > > > > > > On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote: > > > > > >> Good Morning Charlie, > > >> Those units by Pillar Point Electronics look very promising. As I said a > > >> couple of messages back, I need something that can be used on a normally > > >> certificated aircraft. Not sure about the PPE product, but I am checking > > >> into it. > > >> Thanks for the comment. > > >> Happy Skies, > > >> Old Bob > > >> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, > > >> ceengland@bellsouth.net writes: > > >> > > >> > > >> > > >> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: > > >> > > > >> > To me, they look and sound just like the ones that were used > > >> > on those Ford gasoline fired heaters back in the thirties. But > > >> my memory > > >> > could be fooling me. > > >> > > > >> > Those were probably the Stewart Warner or Bendix pumps. > > >> > Whadda Ya Think? > > >> > > > >> > If so. does that mean I need to monitor the frequency some > > >> > how? > > >> > > > >> > This is getting complicated,. No wonder nobody does it! > > >> > > > >> > Happy Skies, > > >> > > > >> > Old Bob > > >> > > > >> > I am not sure of the application here, but I > > >> > believe that there should be a significant pressure drop on the > > >> output of > > >> > the pump, when there is no longer any fuel. This being the > > >> case, perhaps > > >> > you could use a pressure switch, similar to what is used to > > >> monitor engine > > >> > oil pressure and turn on the hobbs meter, on some aircraft. You > > >> would need > > >> > to check the pressure differential between pumping fuel and > > >> empty tank > > >> > pumping, and use a switch midway between. This would be a > > >> normally closed > > >> > switch which would open when there is fuel flow and close, to > > >> turn on the > > >> > light when there is no more fuel to pump. > > >> > > > >> > Not sure if this is a viable option for your > > >> > application, but might work, and is very simple. (I especially like > > >> > simple:-) > > >> > > > >> > Roger > > >> > > > >> If you're using it as a transfer pump, there won't be a lot of > > >> pressure > > >> since it will be just the 'head' from one tank to the other. Often no > > >> more than a few inches of rise, plus the resistance of the tubing. > > >> > > >> How about one of the sensing devices using light to detect the > > >> presence > > >> of liquid? I bought a couple several years ago, intending to use > > >> them to > > >> monitor end-of-transfer from my aux tanks, then forgot to install > > >> them.... They mount in a single hole & have a cone shaped plexi > > >> tip. An > > >> LED shines out through the plexi; presence/absence of liquid > > >> changes the > > >> light reflected back into the photocell in the same housing, changing > > >> the state of the sense line. > > >> > > >> If that interests you, I'll try to locate the name of the device & a > > >> source for you. > > >> > > >> Charlie > > >> > > >> * > > >> > > >> > > >> * > > >> > > > > > > > > > ________________________________ Message 2 _____________________________________ > > > Time: 05:43:01 AM PST US > > Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > From: "rampil" > > > Good engineering principles favor measuring the actual parameter > > you want, rather than a surrogate, especially when there is no > > reliable one-to-one mapping of one to the other. > > > In the case of current draw, for example, overheating the coil or dirt > > in the mechanism will probably change the current draw > > Pressure downstream would depend on where the fill hose enters the > > downstream tank, if at the bottom, or at a positive hydrostatic head, the > > pressure downstream of the pump will stay positive while there is fuel > > in the tank. > > > What about measuring fuel level in the feeding tank, is not that what you > > really want to make a decision with? When it reads zero, stop pumping? > > > -------- > > Ira N224XS > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=294942#294942 > > > ________________________________ Message 3 _____________________________________ > > > Time: 05:48:55 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow > > > Good Morning Bill, > > > Wow! > > > It appears that any suitable current measuring device will be a lot more > > complex than my feeble brain can comprehend. > > > Thanks to you and all the others that have contributed to my on going > > education. > > > In any case, it does seem that a few breadboard experiments are in order. > > > Happy Skies, > > > Old Bob > > > In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time, > sportav8r@gmail.com writes: > > > How about some filtering on the "input" line of the ammeter? If we're > > looking at constant-amplitude square wave current pulses of varying frequency, > > > a capacitive filter to perform an "integral" function might give you an > > average-current-over-time measurement that closely matches the frequency and > > therefore the load on the pump. In practice, I am not sure from listening > > to my Facet pump all these years how much the frequency changes as a > > function of load. There is a sound change as it self-primes when I first hit > > it > > before engine-start. > > > Just a thought. I had to do the pneumatic equivalent (expansion chamber > > plus input restrictor) to keep my manifold pressure digital readout from > > jumping all around in an un-readable fashion. A little RC pi or L network > > might do what you need. > > > Bill B. > > > On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net_ > > (mailto:ceengland@bellsouth.net) > wrote: > > > <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > > > > Certificated. Bummer. > > > If you think you can legally use current sensing, have you tried a > > restricter in the pump's output to see if it will raise the current enough to > > be > > measurable vs the no-flow state? > > > On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote: > > > Good Morning Charlie, > > Those units by Pillar Point Electronics look very promising. As I said a > > couple of messages back, I need something that can be used on a normally > > certificated aircraft. Not sure about the PPE product, but I am checking into > > > it. > > Thanks for the comment. > > Happy Skies, > > Old Bob > > In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, > > _ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes: > > > <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > > > > On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: > > > > > > To me, they look and sound just like the ones that were used > > > on those Ford gasoline fired heaters back in the thirties. But > > my memory > > > could be fooling me. > > > > > > Those were probably the Stewart Warner or Bendix pumps. > > > Whadda Ya Think? > > > > > > If so. does that mean I need to monitor the frequency some > > > how? > > > > > > This is getting complicated,. No wonder nobody does it! > > > > > > Happy Skies, > > > > > > Old Bob > > > > > > I am not sure of the application here, but I > > > believe that there should be a significant pressure drop on the > > output of > > > the pump, when there is no longer any fuel. This being the > > case, perhaps > > > you could use a pressure switch, similar to what is used to > > monitor engine > > > oil pressure and turn on the hobbs meter, on some aircraft. You > > would need > > > to check the pressure differential between pumping fuel and > > empty tank > > > pumping, and use a switch midway between. This would be a > > normally closed > > > switch which would open when there is fuel flow and close, to > > turn on the > > > light when there is no more fuel to pump. > > > > > > Not sure if this is a viable option for your > > > application, but might work, and is very simple. (I especially like > > > simple:-) > > > > > > Roger > > > > > If you're using it as a transfer pump, there won't be a lot of > > pressure > > since it will be just the 'head' from one tank to the other. Often no > > more than a few inches of rise, plus the resistance of the tubing. > > > How about one of the sensing devices using light to detect the > > presence > > of liquid? I bought a couple several years ago, intending to use > > them to > > monitor end-of-transfer from my aux tanks, then forgot to install > > them.... They mount in a single hole & have a cone shaped plexi > > tip. An > > LED shines out through the plexi; presence/absence of liquid > > changes the > > light reflected back into the photocell in the same housing, changing > > the state of the sense line. > > > If that interests you, I'll try to locate the name of the device & a > > source for you. > > > Charlie > > > ________________________________ Message 4 _____________________________________ > > > Time: 06:09:04 AM PST US > > Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > From: "Jon Finley" > > > =0AI find this discussion very interesting and hope for an inexpensive solu > > tion. I really like that Pillar Point flow detector but the price is more > > than I'd like to spend.=0A =0AJust to add some data points.... In my case, > > I know the fuel level in the tank but I wish to know when fuel stops being > > delivered to that tank so alternate plans can be made. So, a "fuel is not f > > lowing" indicator would add a level of comfort (would be "nice" but certain > > ly not mandatory since I am currently flying without this).=0A =0AMore spec > > ifically, I have a large main tank from which fuel is pumped into the heade > > r. The header is about 5 gallons (one hour of flight time). I typically l > > eave my transfer pump on all the time. If it were to stop and I didn't not > > ice (which is likely), I have a warning light that will come on at about 2. > > 5-3 gallons. That leaves me with about 30 minutes to figure out what to do > > . If I had known immediately, I would have had 60 minutes. Of course, I h > > ave a backup fuel pump which I would immediately switch on. However; it ca > > n take some time before seeing the fuel level start to rise. When dealing w > > ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a big > > deal (at least in terms of my stress level - FYI, I live out west were air > > ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0AN314JF > > - Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www.fi > nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message-----=0AFrom: " > > rampil" =0ASent: Tuesday, April 20, 2010 6:41am=0ATo: > > aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet pu > > =0A=0AGood engineering principles favor measuring th > > e actual parameter=0Ayou want, rather than a surrogate, especially when the > > re is no=0Areliable one-to-one mapping of one to the other.=0A=0AIn the cas > > e of current draw, for example, overheating the coil or dirt=0Ain the mecha > > nism will probably change the current draw=0APressure downstream would depe > > nd on where the fill hose enters the =0Adownstream tank, if at the bottom, > > or at a positive hydrostatic head, the =0Apressure downstream of the pump w > > ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about measur > > ing fuel level in the feeding tank, is not that what you=0Areally want to m > > ake a decision with? When it reads zero, stop pumping?=0A=0A--------=0AIra > > N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matron > > ================0A=0A=0A=0A > > > ________________________________ Message 5 _____________________________________ > > > Time: 07:51:11 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: > > > Test --- Do Not Archive > > > In a message dated > > > ________________________________ Message 6 _____________________________________ > > > Time: 07:58:18 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > Good Morning Ira, > > > I have what I consider to be relatively good fuel gauges in the tanks, but > > find that there is at least a ten to fifteen minute window between where > > the gauge says empty and it actually will be dry. I do not wish to turn the > > pump off too soon and have fuel in the tank that has not been used and I do > > not like to run the pump when it is not actually pumping fuel. > > > It would be very nice to be able to verify the accuracy of the fuel gauge > > by noting when the pump stops pumping fuel rather than running the pump > > while dry for possibly an extra ten to fifteen minutes every time I utilize the > > > auxiliary fuel tank. > > > I do have excellent fuel use measuring capability and what I do now is note > > the fuel burned number when I turn on the pump and shut it off when the > > amount of fuel known to be in the tank has been burned. > > > Nevertheless, it would be nice to know within seconds when the tank has run > > dry so that the pump could be turned off. > > > I really would rather not be running the pump when it is not pumping fuel. > > > Happy Skies, > > > Old Bob > > > In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time, > ira.rampil@gmail.com writes: > > > --> AeroElectric-List message posted by: "rampil" > > > Good engineering principles favor measuring the actual parameter > > you want, rather than a surrogate, especially when there is no > > reliable one-to-one mapping of one to the other. > > > In the case of current draw, for example, overheating the coil or dirt > > in the mechanism will probably change the current draw > > Pressure downstream would depend on where the fill hose enters the > > downstream tank, if at the bottom, or at a positive hydrostatic head, the > > pressure downstream of the pump will stay positive while there is fuel > > in the tank. > > > What about measuring fuel level in the feeding tank, is not that what you > > really want to make a decision with? When it reads zero, stop pumping? > > > -------- > > Ira N224XS > > > ________________________________ Message 7 _____________________________________ > > > Time: 10:35:34 AM PST US > > From: Mike Welch > > Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > Bob=2C > > > Pardon me for butting in=2C but from my experience with certificated airp > > lanes=2C it is virtually impossible to get a field approval like you're aft > > er. > > > I used to have a 1961 Cessna 172=2C with an O-300 Continental. On those > > hot mid-summer California days (100+)=2C my oil temps got well into the red > > on climbout!! I checked the accuracy of the gauge=2C and it was correct! > > > Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn't c > > ome with one=2C but I could get a later model 172 oil cooler to fit. I sen > > t off my Form 337 to the local FSDO=2C and their first reaction was "NO!" > > Their attitude was "if it didn't come with one=2C it doesn't need one!!" > > > I was irritated (to say the least)=2C and requested an appeal. They fina > > lly relented and said it would be okay. For crying out loud =2C it was jus > > t an oil cooler!! (all certified parts=2C too) > > > My opinion is=3B there ain't no way you can legally add any kind of perma > > nent parts to modify to your fuel pump=2C fuel lines=2C or anything else=2C > > on a certificated airplane=2C without that approved 337. > > > Just my opinion................. > > > Mike Welch > > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > Good Morning Ira=2C > > > I have what I consider to be relatively good fuel gauges in the tanks=2C bu > > t find that there is at least a ten to fifteen minute window between where > > the gauge says empty and it actually will be dry. I do not wish to turn the > > pump off too soon and have fuel in the tank that has not been used and I d > > o not like to run the pump when it is not actually pumping fuel. > > > It would be very nice to be able to verify the accuracy of the fuel gauge b > > y noting when the pump stops pumping fuel rather than running the pump whil > > e dry for possibly an extra ten to fifteen minutes every time I utilize the > > auxiliary fuel tank. > > > I do have excellent fuel use measuring capability and what I do now is note > > the fuel burned number when I turn on the pump and shut it off when the am > > ount of fuel known to be in the tank has been burned. > > > Nevertheless=2C it would be nice to know within seconds when the tank has r > > un dry so that the pump could be turned off. > > > I really would rather not be running the pump when it is not pumping fuel. > > > Happy Skies=2C > > > Old Bob > > > In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.ramp > il@gmail.com writes: > > > Good engineering principles favor measuring the actual parameter > > you want=2C rather than a surrogate=2C especially when there is no > > reliable one-to-one mapping of one to the other. > > > In the case of current draw=2C for example=2C overheating the coil or dirt > > in the mechanism will probably change the current draw > > Pressure downstream would depend on where the fill hose enters the > > downstream tank=2C if at the bottom=2C or at a positive hydrostatic head=2C > > the > > pressure downstream of the pump will stay positive while there is fuel > > in the tank. > > > What about measuring fuel level in the feeding tank=2C is not that what you > > really want to make a decision with? When it reads zero=2C stop pumping? > > > -------- > > Ira N224XS > > > _________________________________________________________________ > > Hotmail is redefining busy with tools for the New Busy. Get more from your > > inbox. > http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O > > N:WL:en-US:WM_HMP:042010_2 > > > ________________________________ Message 8 _____________________________________ > > > Time: 11:05:32 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > Good Afternoon Mike, > > > Believe it or not I do understand your frustration and the problems that > > are faced when dealing with the FAA. > > It is my opinion that the vast majority of the folks at FAA want to do a > > good job, but are so hamstrung with regulations and paper work that it is > > easier to just say no. > > > However, I have had fairly good luck getting local approvals from my > > supervising FSDO. > > > As I think we can all agree, each FSDO is a kingdom unto itself and what is > > easy to get approved at one office may be impossible at another. > > Nevertheless, I have gotten several local approvals here locally. I do hold an > > A&P > > with Inspection Authorization. It does help me know who I should present the > > data to and how the presentation should be made. > > > In general, if we can think of a way to add something that has no chance of > > interfering with required equipment, the local approval has a better > > chance of being approved. > > > Once again, the FAA has no obligation to ever issue a local approval. In > > fact, if an individual inspector does issue the approval, he is doing it on > > his own knowledge and is personally responsible for what happens. In many > > ways it is surprising that any FAA inspector ever issues a local approval. > > He/she has no obligation to do so. It is just a privilege he has been > > accorded. Failure to do so does not hurt his career at all, but making a dumb > > > approval could end his career. > > > Happy Skies, > > > Old Bob > > > In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time, > mdnanwelch7@hotmail.com writes: > > > Bob, > > > Pardon me for butting in, but from my experience with certificated > > airplanes, it is virtually impossible to get a field approval like you're > > after. > > > I used to have a 1961 Cessna 172, with an O-300 Continental. On those hot > > mid-summer California days (100+), my oil temps got well into the red on > > climbout!! I checked the accuracy of the gauge, and it was correct! > > > Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't come > > with one, but I could get a later model 172 oil cooler to fit. I sent off > > my Form 337 to the local FSDO, and their first reaction was "NO!" Their > > attitude was "if it didn't come with one, it doesn't need one!!" > > > I was irritated (to say the least), and requested an appeal. They finally > > relented and said it would be okay. For crying out loud , it was just an > > oil cooler!! (all certified parts, too) > > > My opinion is; there ain't no way you can legally add any kind of > > permanent parts to modify to your fuel pump, fuel lines, or anything else, on > > a > > certificated airplane, without that approved 337. > > > Just my opinion................. > > > Mike Welch > > > ________________________________ Message 9 _____________________________________ > > > Time: 01:53:26 PM PST US > > Subject: AeroElectric-List: Re: switch breaker on ALT field > > From: "rckol" > > > Switch breakers will function for this application. > > > I have read conflicting reports about the long term reliability of these. Some > > folks end up tearing them out because they don't hold up and others have no > > trouble > > with them. Sorry, I don't have any brand specific recommendations. I > > am not going to use them. > > > Dick > > > -------- > > rck > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=295024#295024 > > > ________________________________ Message 10 ____________________________________ > > > Time: 03:38:33 PM PST US > > Subject: AeroElectric-List: S704-1 on Hot Side of Firewall? > > From: "Noah" > > > I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco T9A > > with an operating temp limit of 85C (185F). This seems a bit low for mounting > > in the engine compartment on the firewall. where I had been planning to mount > > it. I called B&C to ask them if they recommended mounting these in the engine > > compartment and the gentleman I spoke with was not sure - he recommended a post > > here. > > > Anybody know what the firewall temps can climb to?? Anybody mounted one of > > these > > firewall forward in an RV and had problems? Or had it last 2000 hours without > > issue?? > > > -------- > > Highest Regards, > > > Noah Forden > > RV-7A > > Rhode Island > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=295030#295030 > > > ________________________________ Message 11 ____________________________________ > > > Time: 08:30:35 PM PST US > > From: "Robert L. Nuckolls, III" > > Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall? > > > At 05:36 PM 4/20/2010, you wrote: > > > > > >I requested the spec sheet for the S704-1 relay from B&C, and it is > > >a Tyco T9A with an operating temp limit of 85C (185F). This seems a > > >bit low for mounting in the engine compartment on the firewall. > > >where I had been planning to mount it. I called B&C to ask them if > > >they recommended mounting these in the engine compartment and the > > >gentleman I spoke with was not sure - he recommended a post here. > > > > > >Anybody know what the firewall temps can climb to?? Anybody mounted > > >one of these firewall forward in an RV and had problems? Or had it > > >last 2000 hours without issue?? > > > It will be fine. These devices and their close > > cousins are used under the hood of motor vehicles > > and they're fine. > > > The various companies I've worked for have done > > numerous studies of temperature under the cowl > > and found that nothing gets really all that hot > > as long as it's not exposed to direct infra-red > > radiation from stacks (particularly turbochargers). > > I've seen some RG battery cases melted because they > > were too close to exhaust pipes. > > > Bob . . . > > > ________________________________ Message 12 ____________________________________ > > > Time: 08:36:06 PM PST US > > From: "Robert L. Nuckolls, III" > > Subject: Re: AeroElectric-List: Re: switch breaker on ALT field > > > At 03:50 PM 4/20/2010, you wrote: > > > > > >Switch breakers will function for this application. > > > > > >I have read conflicting reports about the long term reliability of > > >these. Some folks end up tearing them out because they don't hold > > >up and others have no trouble with them. Sorry, I don't have any > > >brand specific recommendations. I am not going to use them. > > > The mil-qualified sw/breakers are fine. Actually, the > > P&B W31 series are reasonably decent too. There's about > > 80K in service in Bonanzas and Barons since way back > > when . . . and yes, a few have failed in a way that > > put smoke in the cockpit . . . but those were the 30A > > devices that control electric prop de-ice. > > > Obviously, you can't get the features in single > > switches of any kind that are offered in the progressive- > > transfer 2-pole toggles (2-10, 2-50, 2-70) but if your > > design goals don't require this feature, then the > > single switches will do. > > > Now, having said that, I'm not sure I'd recommend > > the W31 used upstream of a crowbar ov protection system > > that I designed. I've not studied the trip dynamics of > > this device in that application. The miniature TI/Klixon > > style breakers have been paired with our crowbar ov > > systems by the thousands with good service histories. > > > Bob . . . > > > =================================== > > com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List > > =================================== > cs.com" target="_blank">http://forums.matronics.com > > =================================== > > com/contribution" target="_blank">http://www.matronics.com/contribution > > =================================== > > > * > > * > > ________________________________ Message 12 ____________________________________ Time: 10:40:07 AM PST US From: Sheldon Olesen Subject: Re: AeroElectric-List: High fuel pressure Jerry, I had a similar problem with an occasional high reading. A new ground wire to the sender took care of the problem. Sheldon Olesen On Apr 21, 2010, at 10:46 AM, jerry2dt@aol.com wrote: > > Folks, > > Re-posting from VAF, no joy over there but hope there might be someone here with an idea... > > Normally my fuel pressure with the mech pump runs 30-35 psi and with the boost on goes to 40-ish. Suddenly the other day I got a warning on my GRT EFIS when the pressure went to 190 psi and that has continued since, so am very reluctant to fly until this is sorted out. No engine stumbles or anything otherwise abnormal. Fuel flow is fine. > > This is an injected Bendix system on an IO-360 with 160 trouble free hours since new. > > I've never heard of this before, so if anyone here has ideas, advice, answers, please respond. > > BTW, I love that the EFIS picked this out for me and sent up the flag, very handy. > > Thanks all, > > Jerry Cochran > > > -----Original Message----- > From: AeroElectric-List Digest Server > To: AeroElectric-List Digest List > Sent: Tue, Apr 20, 2010 11:55 pm > Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10 > > * > > > > ======================== > > Online Versions of Today's List Digest Archive > > ======================== > > > > Today's complete AeroElectric-List Digest can also be found in either of the > > two Web Links listed below. The .html file includes the Digest formatted > > in HTML for viewing with a web browser and features Hyperlinked Indexes > > and Message Navigation. The .txt file includes the plain ASCII version > > of the AeroElectric-List Digest and can be viewed with a generic text editor > > such as Notepad or with a web browser. > > > > HTML Version: > > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=html&C hapter 10-04-20&Archive=AeroElectric > > > > Text Version: > > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Ch apter 10-04-20&Archive=AeroElectric > > > > > > ======================== ======================= > > EMail Version of Today's List Digest Archive > > ======================== ======================= > > > > > > ---------------------------------------------------------- > > AeroElectric-List Digest Archive > > --- > > Total Messages Posted Tue 04/20/10: 12 > > ---------------------------------------------------------- > > > > > > Today's Message Index: > > ---------------------- > > > > 1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd) > > 2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil) > > 3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) > > 4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley) > > 5. 07:51 AM - Re: (BobsV35B@aol.com) > > 6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) > > 7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch) > > 8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) > > 9. 01:53 PM - Re: switch breaker on ALT field (rckol) > > 10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah) > > 11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckolls, > > III) > > 12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckolls, > > III) > > > > > > > > ________________________________ Message 1 _____________________________________ > > > > > > Time: 04:40:20 AM PST US > > Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow > > From: Bill Boyd > > > > How about some filtering on the "input" line of the ammeter? If we're > > looking at constant-amplitude square wave current pulses of varying > > frequency, a capacitive filter to perform an "integral" function might give > > you an average-current-over-time measurement that closely matches the > > frequency and therefore the load on the pump. In practice, I am not sure > > from listening to my Facet pump all these years how much the frequency > > changes as a function of load. There is a sound change as it self-primes > > when I first hit it before engine-start. > > > > Just a thought. I had to do the pneumatic equivalent (expansion chamber > > plus input restrictor) to keep my manifold pressure digital readout from > > jumping all around in an un-readable fashion. A little RC pi or L network > > might do what you need. > > > > Bill B. > > > > On Mon, Apr 19, 2010 at 9:56 PM, Charlie England wrote: > > > > > ceengland@bellsouth.net> > > > > > > Certificated. Bummer. > > > > > > If you think you can legally use current sensing, have you tried a > > > restricter in the pump's output to see if it will raise the current enough > > > to be measurable vs the no-flow state? > > > > > > On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote: > > > > > >> Good Morning Charlie, > > >> Those units by Pillar Point Electronics look very promising. As I said a > > >> couple of messages back, I need something that can be used on a normally > > >> certificated aircraft. Not sure about the PPE product, but I am checking > > >> into it. > > >> Thanks for the comment. > > >> Happy Skies, > > >> Old Bob > > >> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, > > >> ceengland@bellsouth.net writes: > > >> > > >> > > >> > > >> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: > > >> > > > >> > To me, they look and sound just like the ones that were used > > >> > on those Ford gasoline fired heaters back in the thirties. But > > >> my memory > > >> > could be fooling me. > > >> > > > >> > Those were probably the Stewart Warner or Bendix pumps. > > >> > Whadda Ya Think? > > >> > > > >> > If so. does that mean I need to monitor the frequency some > > >> > how? > > >> > > > >> > This is getting complicated,. No wonder nobody does it! > > >> > > > >> > Happy Skies, > > >> > > > >> > Old Bob > > >> > > > >> > I am not sure of the application here, but I > > >> > believe that there should be a significant pressure drop on the > > >> output of > > >> > the pump, when there is no longer any fuel. This being the > > >> case, perhaps > > >> > you could use a pressure switch, similar to what is used to > > >> monitor engine > > >> > oil pressure and turn on the hobbs meter, on some aircraft. You > > >> would need > > >> > to check the pressure differential between pumping fuel and > > >> empty tank > > >> > pumping, and use a switch midway between. This would be a > > >> normally closed > > >> > switch which would open when there is fuel flow and close, to > > >> turn on the > > >> > light when there is no more fuel to pump. > > >> > > > >> > Not sure if this is a viable option for your > > >> > application, but might work, and is very simple. (I especially like > > >> > simple:-) > > >> > > > >> > Roger > > >> > > > >> If you're using it as a transfer pump, there won't be a lot of > > >> pressure > > >> since it will be just the 'head' from one tank to the other. Often no > > >> more than a few inches of rise, plus the resistance of the tubing. > > >> > > >> How about one of the sensing devices using light to detect the > > >> presence > > >> of liquid? I bought a couple several years ago, intending to use > > >> them to > > >> monitor end-of-transfer from my aux tanks, then forgot to install > > >> them.... They mount in a single hole & have a cone shaped plexi > > >> tip. An > > >> LED shines out through the plexi; presence/absence of liquid > > >> changes the > > >> light reflected back into the photocell in the same housing, changing > > >> the state of the sense line. > > >> > > >> If that interests you, I'll try to locate the name of the device & a > > >> source for you. > > >> > > >> Charlie > > >> > > >> * > > >> > > >> > > >> * > > >> > > > > > > > > > > ________________________________ Message 2 _____________________________________ > > > > > > Time: 05:43:01 AM PST US > > Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > From: "rampil" > > > > > > Good engineering principles favor measuring the actual parameter > > you want, rather than a surrogate, especially when there is no > > reliable one-to-one mapping of one to the other. > > > > In the case of current draw, for example, overheating the coil or dirt > > in the mechanism will probably change the current draw > > Pressure downstream would depend on where the fill hose enters the > > downstream tank, if at the bottom, or at a positive hydrostatic head, the > > pressure downstream of the pump will stay positive while there is fuel > > in the tank. > > > > What about measuring fuel level in the feeding tank, is not that what you > > really want to make a decision with? When it reads zero, stop pumping? > > > > -------- > > Ira N224XS > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=294942#294942 > > > > > > ________________________________ Message 3 _____________________________________ > > > > > > Time: 05:48:55 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow > > > > Good Morning Bill, > > > > Wow! > > > > It appears that any suitable current measuring device will be a lot more > > complex than my feeble brain can comprehend. > > > > Thanks to you and all the others that have contributed to my on going > > education. > > > > In any case, it does seem that a few breadboard experiments are in order. > > > > Happy Skies, > > > > Old Bob > > > > > > In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time, > > sportav8r@gmail.com writes: > > > > How about some filtering on the "input" line of the ammeter? If we're > > looking at constant-amplitude square wave current pulses of varying frequency, > > > > a capacitive filter to perform an "integral" function might give you an > > average-current-over-time measurement that closely matches the frequency and > > therefore the load on the pump. In practice, I am not sure from listening > > to my Facet pump all these years how much the frequency changes as a > > function of load. There is a sound change as it self-primes when I first hit > > it > > before engine-start. > > > > > > Just a thought. I had to do the pneumatic equivalent (expansion chamber > > plus input restrictor) to keep my manifold pressure digital readout from > > jumping all around in an un-readable fashion. A little RC pi or L network > > might do what you need. > > > > > > Bill B. > > > > On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net_ > > (mailto:ceengland@bellsouth.net) > wrote: > > > > <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > > > > > Certificated. Bummer. > > > > If you think you can legally use current sensing, have you tried a > > restricter in the pump's output to see if it will raise the current enough to > > be > > measurable vs the no-flow state? > > > > On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote: > > > > Good Morning Charlie, > > Those units by Pillar Point Electronics look very promising. As I said a > > couple of messages back, I need something that can be used on a normally > > certificated aircraft. Not sure about the PPE product, but I am checking into > > > > it. > > Thanks for the comment. > > Happy Skies, > > Old Bob > > In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, > > _ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes: > > > > <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > > > > > On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: > > > > > > To me, they look and sound just like the ones that were used > > > on those Ford gasoline fired heaters back in the thirties. But > > my memory > > > could be fooling me. > > > > > > Those were probably the Stewart Warner or Bendix pumps. > > > Whadda Ya Think? > > > > > > If so. does that mean I need to monitor the frequency some > > > how? > > > > > > This is getting complicated,. No wonder nobody does it! > > > > > > Happy Skies, > > > > > > Old Bob > > > > > > I am not sure of the application here, but I > > > believe that there should be a significant pressure drop on the > > output of > > > the pump, when there is no longer any fuel. This being the > > case, perhaps > > > you could use a pressure switch, similar to what is used to > > monitor engine > > > oil pressure and turn on the hobbs meter, on some aircraft. You > > would need > > > to check the pressure differential between pumping fuel and > > empty tank > > > pumping, and use a switch midway between. This would be a > > normally closed > > > switch which would open when there is fuel flow and close, to > > turn on the > > > light when there is no more fuel to pump. > > > > > > Not sure if this is a viable option for your > > > application, but might work, and is very simple. (I especially like > > > simple:-) > > > > > > Roger > > > > > If you're using it as a transfer pump, there won't be a lot of > > pressure > > since it will be just the 'head' from one tank to the other. Often no > > more than a few inches of rise, plus the resistance of the tubing. > > > > How about one of the sensing devices using light to detect the > > presence > > of liquid? I bought a couple several years ago, intending to use > > them to > > monitor end-of-transfer from my aux tanks, then forgot to install > > them.... They mount in a single hole & have a cone shaped plexi > > tip. An > > LED shines out through the plexi; presence/absence of liquid > > changes the > > light reflected back into the photocell in the same housing, changing > > the state of the sense line. > > > > If that interests you, I'll try to locate the name of the device & a > > source for you. > > > > Charlie > > > > > > ________________________________ Message 4 _____________________________________ > > > > > > Time: 06:09:04 AM PST US > > Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > From: "Jon Finley" > > > > =0AI find this discussion very interesting and hope for an inexpensive solu > > tion. I really like that Pillar Point flow detector but the price is more > > than I'd like to spend.=0A =0AJust to add some data points.... In my case, > > I know the fuel level in the tank but I wish to know when fuel stops being > > delivered to that tank so alternate plans can be made. So, a "fuel is not f > > lowing" indicator would add a level of comfort (would be "nice" but certain > > ly not mandatory since I am currently flying without this).=0A =0AMore spec > > ifically, I have a large main tank from which fuel is pumped into the heade > > r. The header is about 5 gallons (one hour of flight time). I typically l > > eave my transfer pump on all the time. If it were to stop and I didn't not > > ice (which is likely), I have a warning light that will come on at about 2. > > 5-3 gallons. That leaves me with about 30 minutes to figure out what to do > > . If I had known immediately, I would have had 60 minutes. Of course, I h > > ave a backup fuel pump which I would immediately switch on. However; it ca > > n take some time before seeing the fuel level start to rise. When dealing w > > ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a big > > deal (at least in terms of my stress level - FYI, I live out west were air > > ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0AN314JF > > - Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www.fi > > nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message-----=0AFrom: " > > rampil" =0ASent: Tuesday, April 20, 2010 6:41am=0ATo: > > aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet pu > > =0A=0AGood engineering principles favor measuring th > > e actual parameter=0Ayou want, rather than a surrogate, especially when the > > re is no=0Areliable one-to-one mapping of one to the other.=0A=0AI n the cas > > e of current draw, for example, overheating the coil or dirt=0Ain the mecha > > nism will probably change the current draw=0APressure downstream would depe > > nd on where the fill hose enters the =0Adownstream tank, if at the bottom, > > or at a positive hydrostatic head, the =0Apressure downstream of the pump w > > ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about measur > > ing fuel level in the feeding tank, is not that what you=0Areally want to m > > ake a decision with? When it reads zero, stop pumping?=0A=0A--------=0AIra > > N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matron > > ================0A=0A=0A=0A > > > > ________________________________ Message 5 _____________________________________ > > > > > > Time: 07:51:11 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: > > > > Test --- Do Not Archive > > > > > > In a message dated > > > > ________________________________ Message 6 _____________________________________ > > > > > > Time: 07:58:18 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > > Good Morning Ira, > > > > I have what I consider to be relatively good fuel gauges in the tanks, but > > find that there is at least a ten to fifteen minute window between where > > the gauge says empty and it actually will be dry. I do not wish to turn the > > pump off too soon and have fuel in the tank that has not been used and I do > > not like to run the pump when it is not actually pumping fuel. > > > > It would be very nice to be able to verify the accuracy of the fuel gauge > > by noting when the pump stops pumping fuel rather than running the pump > > while dry for possibly an extra ten to fifteen minutes every time I utilize the > > > > auxiliary fuel tank. > > > > I do have excellent fuel use measuring capability and what I do now is note > > the fuel burned number when I turn on the pump and shut it off when the > > amount of fuel known to be in the tank has been burned. > > > > Nevertheless, it would be nice to know within seconds when the tank has run > > dry so that the pump could be turned off. > > > > I really would rather not be running the pump when it is not pumping fuel. > > > > Happy Skies, > > > > Old Bob > > > > > > In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time, > > ira.rampil@gmail.com writes: > > > > --> AeroElectric-List message posted by: "rampil" > > > > Good engineering principles favor measuring the actual parameter > > you want, rather than a surrogate, especially when there is no > > reliable one-to-one mapping of one to the other. > > > > In the case of current draw, for example, overheating the coil or dirt > > in the mechanism will probably change the current draw > > Pressure downstream would depend on where the fill hose enters the > > downstream tank, if at the bottom, or at a positive hydrostatic head, the > > pressure downstream of the pump will stay positive while there is fuel > > in the tank. > > > > What about measuring fuel level in the feeding tank, is not that what you > > really want to make a decision with? When it reads zero, stop pumping? > > > > -------- > > Ira N224XS > > > > > > ________________________________ Message 7 _____________________________________ > > > > > > Time: 10:35:34 AM PST US > > From: Mike Welch > > Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > > > > Bob=2C > > > > > > Pardon me for butting in=2C but from my experience with certificated airp > > lanes=2C it is virtually impossible to get a field approval like you're aft > > er. > > > > > > I used to have a 1961 Cessna 172=2C with an O-300 Continental. On those > > hot mid-summer California days (100+)=2C my oil temps got well into the red > > on climbout!! I checked the accuracy of the gauge=2C and it was correct! > > > > > > Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn't c > > ome with one=2C but I could get a later model 172 oil cooler to fit. I sen > > t off my Form 337 to the local FSDO=2C and their first reaction was "NO!" > > Their attitude was "if it didn't come with one=2C it doesn't need one!!" > > > > > > I was irritated (to say the least)=2C and requested an appeal. They fina > > lly relented and said it would be okay. For crying out loud =2C it was jus > > t an oil cooler!! (all certified parts=2C too) > > > > > > My opinion is=3B there ain't no way you can legally add any kind of perma > > nent parts to modify to your fuel pump=2C fuel lines=2C or anything else=2C > > on a certificated airplane=2C without that approved 337. > > > > > > Just my opinion................. > > > > > > Mike Welch > > > > > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > > > > Good Morning Ira=2C > > > > I have what I consider to be relatively good fuel gauges in the tanks=2C bu > > t find that there is at least a ten to fifteen minute window between where > > the gauge says empty and it actually will be dry. I do not wish to turn the > > pump off too soon and have fuel in the tank that has not been used and I d > > o not like to run the pump when it is not actually pumping fuel. > > > > It would be very nice to be able to verify the accuracy of the fuel gauge b > > y noting when the pump stops pumping fuel rather than running the pump whil > > e dry for possibly an extra ten to fifteen minutes every time I utilize the > > auxiliary fuel tank. > > > > I do have excellent fuel use measuring capability and what I do now is note > > the fuel burned number when I turn on the pump and shut it off when the am > > ount of fuel known to be in the tank has been burned. > > > > Nevertheless=2C it would be nice to know within seconds when the tank has r > > un dry so that the pump could be turned off. > > > > I really would rather not be running the pump when it is not pumping fuel. > > > > Happy Skies=2C > > > > Old Bob > > > > > > In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.ramp > > il@gmail.com writes: > > > > Good engineering principles favor measuring the actual parameter > > you want=2C rather than a surrogate=2C especially when there is no > > reliable one-to-one mapping of one to the other. > > > > In the case of current draw=2C for example=2C overheating the coil or dirt > > in the mechanism will probably change the current draw > > Pressure downstream would depend on where the fill hose enters the > > downstream tank=2C if at the bottom=2C or at a positive hydrostatic head=2C > > the > > pressure downstream of the pump will stay positive while there is fuel > > in the tank. > > > > What about measuring fuel level in the feeding tank=2C is not that what you > > really want to make a decision with? When it reads zero=2C stop pumping? > > > > -------- > > Ira N224XS > > > > > > > > _________________________________________________________________ > > Hotmail is redefining busy with tools for the New Busy. Get more from your > > inbox. > > http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL: O > > N:WL:en-US:WM_HMP:042010_2 > > > > ________________________________ Message 8 _____________________________________ > > > > > > Time: 11:05:32 AM PST US > > From: BobsV35B@aol.com > > Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow > > > > Good Afternoon Mike, > > > > Believe it or not I do understand your frustration and the problems that > > are faced when dealing with the FAA. > > It is my opinion that the vast majority of the folks at FAA want to do a > > good job, but are so hamstrung with regulations and paper work that it is > > easier to just say no. > > > > However, I have had fairly good luck getting local approvals from my > > supervising FSDO. > > > > As I think we can all agree, each FSDO is a kingdom unto itself and what is > > easy to get approved at one office may be impossible at another. > > Nevertheless, I have gotten several local approvals here locally. I do hold an > > A&P > > with Inspection Authorization. It does help me know who I should present the > > data to and how the presentation should be made. > > > > In general, if we can think of a way to add something that has no chance of > > interfering with required equipment, the local approval has a better > > chance of being approved. > > > > Once again, the FAA has no obligation to ever issue a local approval. In > > fact, if an individual inspector does issue the approval, he is doing it on > > his own knowledge and is personally responsible for what happens. In many > > ways it is surprising that any FAA inspector ever issues a local approval. > > He/she has no obligation to do so. It is just a privilege he has been > > accorded. Failure to do so does not hurt his career at all, but making a dumb > > > > approval could end his career. > > > > Happy Skies, > > > > Old Bob > > > > > > In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time, > > mdnanwelch7@hotmail.com writes: > > > > Bob, > > > > Pardon me for butting in, but from my experience with certificated > > airplanes, it is virtually impossible to get a field approval like you're > > after. > > > > I used to have a 1961 Cessna 172, with an O-300 Continental. On those hot > > mid-summer California days (100+), my oil temps got well into the red on > > climbout!! I checked the accuracy of the gauge, and it was correct! > > > > Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't come > > with one, but I could get a later model 172 oil cooler to fit. I sent off > > my Form 337 to the local FSDO, and their first reaction was "NO!" Their > > attitude was "if it didn't come with one, it doesn't need one!!" > > > > I was irritated (to say the least), and requested an appeal. They finally > > relented and said it would be okay. For crying out loud , it was just an > > oil cooler!! (all certified parts, too) > > > > My opinion is; there ain't no way you can legally add any kind of > > permanent parts to modify to your fuel pump, fuel lines, or anything else, on > > a > > certificated airplane, without that approved 337. > > > > Just my opinion................. > > > > Mike Welch > > > > > > ________________________________ Message 9 _____________________________________ > > > > > > Time: 01:53:26 PM PST US > > Subject: AeroElectric-List: Re: switch breaker on ALT field > > From: "rckol" > > > > > > Switch breakers will function for this application. > > > > I have read conflicting reports about the long term reliability of these. Some > > folks end up tearing them out because they don't hold up and others have no > > trouble > > with them. Sorry, I don't have any brand specific recommendations. I > > am not going to use them. > > > > Dick > > > > -------- > > rck > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=295024#295024 > > > > > > ________________________________ Message 10 ____________________________________ > > > > > > Time: 03:38:33 PM PST US > > Subject: AeroElectric-List: S704-1 on Hot Side of Firewall? > > From: "Noah" > > > > > > I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco T9A > > with an operating temp limit of 85C (185F). This seems a bit low for mounting > > in the engine compartment on the firewall. where I had been planning to mount > > it. I called B&C to ask them if they recommended mounting these in the engine > > compartment and the gentleman I spoke with was not sure - he recommended a post > > here. > > > > Anybody know what the firewall temps can climb to?? Anybody mounted one of > > these > > firewall forward in an RV and had problems? Or had it last 2000 hours without > > issue?? > > > > -------- > > Highest Regards, > > > > Noah Forden > > RV-7A > > Rhode Island > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=295030#295030 > > > > > > ________________________________ Message 11 ____________________________________ > > > > > > Time: 08:30:35 PM PST US > > From: "Robert L. Nuckolls, III" > > Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall? > > > > > > At 05:36 PM 4/20/2010, you wrote: > > > > > >I requested the spec sheet for the S704-1 relay from B&C, and it is > > >a Tyco T9A with an operating temp limit of 85C (185F). This seems a > > >bit low for mounting in the engine compartment on the firewall. > > >where I had been planning to mount it. I called B&C to ask them if > > >they recommended mounting these in the engine compartment and the > > >gentleman I spoke with was not sure - he recommended a post here. > > > > > >Anybody know what the firewall temps can climb to?? Anybody mounted > > >one of these firewall forward in an RV and had problems? Or had it > > >last 2000 hours without issue?? > > > > It will be fine. These devices and their close > > cousins are used under the hood of motor vehicles > > and they're fine. > > > > The various companies I've worked for have done > > numerous studies of temperature under the cowl > > and found that nothing gets really all that hot > > as long as it's not exposed to direct infra-red > > radiation from stacks (particularly turbochargers). > > I've seen some RG battery cases melted because they > > were too close to exhaust pipes. > > > > Bob . . . > > > > > > ________________________________ Message 12 ____________________________________ > > > > > > Time: 08:36:06 PM PST US > > From: "Robert L. Nuckolls, III" > > Subject: Re: AeroElectric-List: Re: switch breaker on ALT field > > > > > > At 03:50 PM 4/20/2010, you wrote: > > > > > >Switch breakers will function for this application. > > > > > >I have read conflicting reports about the long term reliability of > > >these. Some folks end up tearing them out because they don't hold > > >up and others have no trouble with them. Sorry, I don't have any > > >brand specific recommendations. I am not going to use them. > > > > The mil-qualified sw/breakers are fine. Actually, the > > P&B W31 series are reasonably decent too. There's about > > 80K in service in Bonanzas and Barons since way back > > when . . . and yes, a few have failed in a way that > > put smoke in the cockpit . . . but those were the 30A > > devices that control electric prop de-ice. > > > > Obviously, you can't get the features in single > > switches of any kind that are offered in the progressive- > > transfer 2-pole toggles (2-10, 2-50, 2-70) but if your > > design goals don't require this feature, then the > > single switches will do. > > > > Now, having said that, I'm not sure I'd recommend > > the W31 used upstream of a crowbar ov protection system > > that I designed. I've not studied the trip dynamics of > > this device in that application. The miniature TI/Klixon > > style breakers have been paired with our crowbar ov > > systems by the thousands with good service histories. > > > > Bob . . . > > > > > > > > > > > > ======================== =========== > > com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List > > ======================== =========== > > cs.com" target="_blank">http://forums.matronics.com > > ======================== =========== > > com/contribution" target="_blank">http://www.matronics.com/contribution > > ======================== =========== > > > > > > > > > > > > ________________________________ Message 13 ____________________________________ Time: 10:46:40 AM PST US Subject: AeroElectric-List: Surface temperature sensor From: Q, Has anyone come across an example of a surface temperature sensor (generic)) that could be used on engine parts or perhaps the firewall and send a digital reading back to the panel? Example. - I would like to measure the temperature on the surface of my oil filter/fuel pump and display that value on the panel. FYI - I have stick-on thermometers that work great when performing engine checks on the ground but they are of little use in the air. Thanks, Glenn ________________________________ Message 14 ____________________________________ Time: 11:41:26 AM PST US From: Mike Welch Subject: RE: AeroElectric-List: RE: Designing a circuit question 'Lectric Bob=2C I REALLY like your circuit design regarding the IvoProp motor. In fact =2C I'm planning on building one=2C seeing as how I have an IvoProp...with the motor. If I understand the process correctly=2C by pushing the dpdt switch=2C wh en the motor sees 6 A current=2C the LED will light up. Let go of the dpdt switch quickly=2C and you're in like Flynn. Here's my question: would it be much of a challenge for the motor to lig hten multiple LEDs (in both directions)=2C as it cycles from 0 to 10A? Of course=2C you'd want two separate circuits indicating if you're headed to f lat pitch...or steep pitch=2C or some method to insure you're twisting the prop in the correct direction you intended to. Wouldn't this design I'm asking about be essentially an analog version of a current meter? Example: say you're at zero pitch=2C and you cycle tow ard steep pitch. As the motor's current draw increases=2C it could light a 1A LED=2C then a 2A LED=2C a 3A LED=2C etc=2C etc. Same process for the other prop twist. If a guy had this type of design he could routinely set his prop pitch to a known LED position to achieve maximum value of a variable pitch prop. H e could adjust his engine and prop (LED) to a known performance characteris tic.....i.e......engine rpm 4750=2C pitch in the steep direction #5 LED. Thanks for your ideas! Mike Welch BTW. I built that copper tape groundplane antenna. It works great so far =2C but I'm waiting on the bnc connector/PL 259 adapter for the SWR meter t o adjust it correctly (Radio Shack Friday's delivery)!! _________________________________________________________________ The New Busy is not the old busy. Search=2C chat and e-mail from your inbox .. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O N:WL:en-US:WM_HMP:042010_3 ________________________________ Message 15 ____________________________________ Time: 12:53:45 PM PST US From: "mike gamble" Subject: AeroElectric-List: Battery replacement in Garmin 3 pilot Has anybody had experience replacing the memory battery in the old Garmin 3 pilot GPS. Is it straight forward and is the battery easily obtained in UK? I'm reluctant to discard what has been a trusty old companion over many years, for the sake of a bit of diy tinkering. Thanks Mike XS mono G-CFMP ________________________________ Message 16 ____________________________________ Time: 01:12:37 PM PST US Subject: AeroElectric-List: Re: Surface temperature sensor From: "rampil" Ahhhh, how bout a thermocouple? how bout a resistive probe like many engines use for CHT. This discussion group is replete with temp. monitoring -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295140#295140 ________________________________ Message 17 ____________________________________ Time: 02:04:15 PM PST US Subject: RE: AeroElectric-List: Re: Surface temperature sensor From: Do Not Archive Thanks IRA, Yes, I'll do some digging. I was thinking about something with a flat profile and perhaps a stick on for a flat surface. There must be somebody putting out a device that can be fastened to a flat surface that has two wires sticking out of it. Glenn Do Not Archive -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of rampil Sent: Wednesday, April 21, 2010 4:11 PM Subject: AeroElectric-List: Re: Surface temperature sensor Ahhhh, how bout a thermocouple? how bout a resistive probe like many engines use for CHT. This discussion group is replete with temp. monitoring -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295140#295140 ________________________________ Message 18 ____________________________________ Time: 02:28:55 PM PST US From: "The Kuffels" Subject: Re: AeroElectric-List: Accurate Altitude and Airspeed Sam, << Dynon FlightDek ... winds aloft display ... pretty inaccurate ... look after my static ports ... investigating the wedges at the static ports. >> If you wish, I have an Excel spreadsheet which will help you measure the accuracy of your pitot/static system. For various indicated airspeeds and pressure altitudes (set your altimeter to 29.92) you fly an approximate box course noting the GPS track and groundspeed. (Also note temperature for later use.) Enter the 4 data points and the spreadsheet calculates 4 true airspeed and wind values. The 4th, redundant, datapoint allows an internal quality check since the 4 calculated air and wind speeds should be very close to each other. Discard any measurement which isn't. Knowing true airspeed, pressure altitude and temperature do a "reverse" E-6B calculation to determine what your indicated airspeed *should* have been. Graphs of errors for constant indicated airspeeds vs altitudes and constant altitudes vs airspeeds will give you an excellent view of system/instrument errors. Not only can you determine even subtle effects of any changes to your pitot/static system but when you are done you have accurate graphs of true vs indicated airspeeds. This is an exercise everyone should do as part of any homebuilt test period. Email me direct off-list for a copy of the spreadsheet: kuffel@cyberport.net Tom Kuffel EAA Flight Advisor ________________________________ Message 19 ____________________________________ Time: 04:21:16 PM PST US Subject: AeroElectric-List: Re: Surface temperature sensor From: "rampil" The actual sensors for t/c or thermistors are tiny inside those cans they get mounted in. A tc is just two wires twisted in each other. Either is easy to JB Weld in place on a surface -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295168#295168 ________________________________ Message 20 ____________________________________ Time: 04:42:37 PM PST US From: Lincoln Keill Subject: AeroElectric-List: Diode confusion Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab for my SD-8 relay control and thought -- "gee, maybe I better check this diode to make sure it's good before I do this" -- what could be simpler? -Current flows from the non-band side of the diode to the band side, but not the ot her way (just like the schematic), right? -Get out the multi-meter, set i t to measure ohms. -I put the red lead on the non-band side and the black lead on the band side and expect to see zero (or very little) resistance. -Uh oh....infinite resistance...not good...do I have the leads reversed o n the meter? -Nope. -I reverse the leads (red on band-side and black on non-band-side...expecting to see infinite resistance) and see...uh oh...3 milliohms. -Now I'm really confused. -I pull another diode out of the p acket and repeat the test....same result. -I check the heat-sinked bridge recitifier for the ebus regular feed...same result. I believe the chance that three different components turned out defective o r mis-labeled are pretty remote and the chance that my knowledge of all thi ngs electric is (once again) in need of improvement. -Perhaps I just don' t understand how the multimeter works. My question: For a functioning diode, shouldn't current flow from the red lead of the mu ltimeter when it's placed on the non-band side of the diode, to the black l ead of the multimeter when it's on the band-side of the diode and indicate zero (or very little resistance)? Thanks to whoever can set me straight on this ridiculously simple concept. Do Not Archive Lincoln KeillRV-7A ________________________________ Message 21 ____________________________________ Time: 05:05:53 PM PST US From: Harley Subject: Re: AeroElectric-List: Diode confusion Your diodes are fine...you hooked the meter up backwards! See here for an explanation: http://tinyurl.com/26pwfwg Harley ------------------------------------------------------------------------ On 4/21/2010 7:41 PM, Lincoln Keill wrote: > Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab > for my SD-8 relay control and thought -- "gee, maybe I better check > this diode to make sure it's good before I do this" -- what could be > simpler? Current flows from the non-band side of the diode to the > band side, but not the other way (just like the schematic), right? > Get out the multi-meter, set it to measure ohms. I put the red lead > on the non-band side and the black lead on the band side and expect to > see zero (or very little) resistance. Uh oh....infinite > resistance...not good...do I have the leads reversed on the meter? > Nope. I reverse the leads (red on band-side and black on > non-band-side...expecting to see infinite resistance) and see...uh > oh...3 milliohms. Now I'm really confused. I pull another diode out > of the packet and repeat the test....same result. I check the > heat-sinked bridge recitifier for the ebus regular feed...same result. > > I believe the chance that three different components turned out > defective or mis-labeled are pretty remote and the chance that my > knowledge of all things electric is (once again) in need of > improvement. Perhaps I just don't understand how the multimeter works. > > My question: > > For a functioning diode, shouldn't current flow from the red lead of > the multimeter when it's placed on the non-band side of the diode, to > the black lead of the multimeter when it's on the band-side of the > diode and indicate zero (or very little resistance)? > > Thanks to whoever can set me straight on this ridiculously simple concept. > > Do Not Archive > > Lincoln Keill > RV-7A > > * > > > * > > > Checked by AVG - www.avg.com > > ________________________________ Message 22 ____________________________________ Time: 05:07:41 PM PST US From: Tim Andres Subject: Re: AeroElectric-List: High fuel pressure I bought all my GRT stuff new but second hand and had it shipped to GRT for inspection. They asked me if I wanted to swap out the fuel sender for the "good" one. I did this and was told the standard one has a rather short life expectancy. If you find its the sender you might get the good one this time. Tim A ________________________________ From: "jerry2dt@aol.com" Sent: Wed, April 21, 2010 8:46:44 AM Subject: AeroElectric-List: High fuel pressure ________________________________ Folks, Re-posting from VAF, no joy over there but hope there might be someone here with an idea... Normally my fuel pressure with the mech pump runs 30-35 psi and with the boost on goes to 40-ish. Suddenly the other day I got a warning on my GRT EFIS when the pressure went to 190 psi and that has continued since, so am very reluctant to fly until this is sorted out. No engine stumbles or anything otherwise abnormal. Fuel flow is fine. This is an injected Bendix system on an IO-360 with 160 trouble free hours since new. I've never heard of this before, so if anyone here has ideas, advice, answers, please respond. BTW, I love that the EFIS picked this out for me and sent up the flag, very handy. Thanks all, Jerry Cochran -----Original Message----- From: AeroElectric-List Digest Server Sent: Tue, Apr 20, 2010 11:55 pm Subject: AeroElectric-List Digest: 12 Msgs - 04/20/10 * ================================================= Online Versions of Today's List Digest Archive ================================================= Today's complete AeroElectric-List Digest can also be found in either of the two Web Links listed below. The .html file includes the Digest formatted in HTML for viewing with a web browser and features Hyperlinked Indexes and Message Navigation. The .txt file includes the plain ASCII version of the AeroElectric-List Digest and can be viewed with a generic text editor such as Notepad or with a web browser. HTML Version: http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter 10-04-20&Archive=AeroElectric Text Version: http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 10-04-20&Archive=AeroElectric =============================================== EMail Version of Today's List Digest Archive =============================================== ---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 04/20/10: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:40 AM - Re: Facet pumps: Energy vs. Flow (Bill Boyd) 2. 05:43 AM - Re: Facet pumps: Energy vs. Flow (rampil) 3. 05:48 AM - Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) 4. 06:09 AM - Re: Re: Facet pumps: Energy vs. Flow (Jon Finley) 5. 07:51 AM - Re: (BobsV35B@aol.com) 6. 07:58 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) 7. 10:35 AM - Re: Facet pumps: Energy vs. Flow (Mike Welch) 8. 11:05 AM - Re: Re: Facet pumps: Energy vs. Flow (BobsV35B@aol.com) 9. 01:53 PM - Re: switch breaker on ALT field (rckol) 10. 03:38 PM - S704-1 on Hot Side of Firewall? (Noah) 11. 08:30 PM - Re: S704-1 on Hot Side of Firewall? (Robert L. Nuckolls, III) 12. 08:36 PM - Re: Re: switch breaker on ALT field (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:40:20 AM PST US Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow From: Bill Boyd How about some filtering on the "input" line of the ammeter? If we're looking at constant-amplitude square wave current pulses of varying frequency, a capacitive filter to perform an "integral" function might give you an average-current-over-time measurement that closely matches the frequency and therefore the load on the pump. In practice, I am not sure from listening to my Facet pump all these years how much the frequency changes as a function of load. There is a sound change as it self-primes when I first hit it before engine-start. Just a thought. I had to do the pneumatic equivalent (expansion chamber plus input restrictor) to keep my manifold pressure digital readout from jumping all around in an un-readable fashion. A little RC pi or L network might do what you need. Bill B. On Mon, Apr 19, 2010 at 9:56 PM, Charlie England wrote: > ceengland@bellsouth.net> > > Certificated. Bummer. > > If you think you can legally use current sensing, have you tried a > restricter in the pump's output to see if it will raise the current enough > to be measurable vs the no-flow state? > > On 4/19/2010 6:16 PM, BobsV35B@aol.com wrote: > >> Good Morning Charlie, >> Those units by Pillar Point Electronics look very promising. As I said a >> couple of messages back, I need something that can be used on a normally >> certificated aircraft. Not sure about the PPE product, but I am checking >> into it. >> Thanks for the comment. >> Happy Skies, >> Old Bob >> In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, >> ceengland@bellsouth.net writes: >> >> >> >> On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: >> > >> > To me, they look and sound just like the ones that were used >> > on those Ford gasoline fired heaters back in the thirties. But >> my memory >> > could be fooling me. >> > >> > Those were probably the Stewart Warner or Bendix pumps. >> > Whadda Ya Think? >> > >> > If so. does that mean I need to monitor the frequency some >> > how? >> > >> > This is getting complicated,. No wonder nobody does it! >> > >> > Happy Skies, >> > >> > Old Bob >> > >> > I am not sure of the application here, but I >> > believe that there should be a significant pressure drop on the >> output of >> > the pump, when there is no longer any fuel. This being the >> case, perhaps >> > you could use a pressure switch, similar to what is used to >> monitor engine >> > oil pressure and turn on the hobbs meter, on some aircraft. You >> would need >> > to check the pressure differential between pumping fuel and >> empty tank >> > pumping, and use a switch midway between. This would be a >> normally closed >> > switch which would open when there is fuel flow and close, to >> turn on the >> > light when there is no more fuel to pump. >> > >> > Not sure if this is a viable option for your >> > application, but might work, and is very simple. (I especially like >> > simple:-) >> > >> > Roger >> > >> If you're using it as a transfer pump, there won't be a lot of >> pressure >> since it will be just the 'head' from one tank to the other. Often no >> more than a few inches of rise, plus the resistance of the tubing. >> >> How about one of the sensing devices using light to detect the >> presence >> of liquid? I bought a couple several years ago, intending to use >> them to >> monitor end-of-transfer from my aux tanks, then forgot to install >> them.... They mount in a single hole & have a cone shaped plexi >> tip. An >> LED shines out through the plexi; presence/absence of liquid >> changes the >> light reflected back into the photocell in the same housing, changing >> the state of the sense line. >> >> If that interests you, I'll try to locate the name of the device & a >> source for you. >> >> Charlie >> >> * >> >> >> * >> > > ________________________________ Message 2 _____________________________________ Time: 05:43:01 AM PST US Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow From: "rampil" Good engineering principles favor measuring the actual parameter you want, rather than a surrogate, especially when there is no reliable one-to-one mapping of one to the other. In the case of current draw, for example, overheating the coil or dirt in the mechanism will probably change the current draw Pressure downstream would depend on where the fill hose enters the downstream tank, if at the bottom, or at a positive hydrostatic head, the pressure downstream of the pump will stay positive while there is fuel in the tank. What about measuring fuel level in the feeding tank, is not that what you really want to make a decision with? When it reads zero, stop pumping? -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=294942#294942 ________________________________ Message 3 _____________________________________ Time: 05:48:55 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Facet pumps: Energy vs. Flow Good Morning Bill, Wow! It appears that any suitable current measuring device will be a lot more complex than my feeble brain can comprehend. Thanks to you and all the others that have contributed to my on going education. In any case, it does seem that a few breadboard experiments are in order. Happy Skies, Old Bob In a message dated 4/20/2010 6:41:53 A.M. Central Daylight Time, sportav8r@gmail.com writes: How about some filtering on the "input" line of the ammeter? If we're looking at constant-amplitude square wave current pulses of varying frequency, a capacitive filter to perform an "integral" function might give you an average-current-over-time measurement that closely matches the frequency and therefore the load on the pump. In practice, I am not sure from listening to my Facet pump all these years how much the frequency changes as a function of load. There is a sound change as it self-primes when I first hit it before engine-start. Just a thought. I had to do the pneumatic equivalent (expansion chamber plus input restrictor) to keep my manifold pressure digital readout from jumping all around in an un-readable fashion. A little RC pi or L network might do what you need. Bill B. On Mon, Apr 19, 2010 at 9:56 PM, Charlie England <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > wrote: <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > Certificated. Bummer. If you think you can legally use current sensing, have you tried a restricter in the pump's output to see if it will raise the current enough to be measurable vs the no-flow state? On 4/19/2010 6:16 PM, _BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote: Good Morning Charlie, Those units by Pillar Point Electronics look very promising. As I said a couple of messages back, I need something that can be used on a normally certificated aircraft. Not sure about the PPE product, but I am checking into it. Thanks for the comment. Happy Skies, Old Bob In a message dated 4/19/2010 4:50:49 P.M. Central Daylight Time, _ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) writes: <_ceengland@bellsouth.net_ (mailto:ceengland@bellsouth.net) > On 4/19/2010 3:03 PM, ROGER & JEAN CURTIS wrote: > > To me, they look and sound just like the ones that were used > on those Ford gasoline fired heaters back in the thirties. But my memory > could be fooling me. > > Those were probably the Stewart Warner or Bendix pumps. > Whadda Ya Think? > > If so. does that mean I need to monitor the frequency some > how? > > This is getting complicated,. No wonder nobody does it! > > Happy Skies, > > Old Bob > > I am not sure of the application here, but I > believe that there should be a significant pressure drop on the output of > the pump, when there is no longer any fuel. This being the case, perhaps > you could use a pressure switch, similar to what is used to monitor engine > oil pressure and turn on the hobbs meter, on some aircraft. You would need > to check the pressure differential between pumping fuel and empty tank > pumping, and use a switch midway between. This would be a normally closed > switch which would open when there is fuel flow and close, to turn on the > light when there is no more fuel to pump. > > Not sure if this is a viable option for your > application, but might work, and is very simple. (I especially like > simple:-) > > Roger > If you're using it as a transfer pump, there won't be a lot of pressure since it will be just the 'head' from one tank to the other. Often no more than a few inches of rise, plus the resistance of the tubing. How about one of the sensing devices using light to detect the presence of liquid? I bought a couple several years ago, intending to use them to monitor end-of-transfer from my aux tanks, then forgot to install them.... They mount in a single hole & have a cone shaped plexi tip. An LED shines out through the plexi; presence/absence of liquid changes the light reflected back into the photocell in the same housing, changing the state of the sense line. If that interests you, I'll try to locate the name of the device & a source for you. Charlie ________________________________ Message 4 _____________________________________ Time: 06:09:04 AM PST US Subject: RE: AeroElectric-List: Re: Facet pumps: Energy vs. Flow From: "Jon Finley" =0AI find this discussion very interesting and hope for an inexpensive solu tion. I really like that Pillar Point flow detector but the price is more than I'd like to spend.=0A =0AJust to add some data points.... In my case, I know the fuel level in the tank but I wish to know when fuel stops being delivered to that tank so alternate plans can be made. So, a "fuel is not f lowing" indicator would add a level of comfort (would be "nice" but certain ly not mandatory since I am currently flying without this).=0A =0AMore spec ifically, I have a large main tank from which fuel is pumped into the heade r. The header is about 5 gallons (one hour of flight time). I typically l eave my transfer pump on all the time. If it were to stop and I didn't not ice (which is likely), I have a warning light that will come on at about 2. 5-3 gallons. That leaves me with about 30 minutes to figure out what to do . If I had known immediately, I would have had 60 minutes. Of course, I h ave a backup fuel pump which I would immediately switch on. However; it ca n take some time before seeing the fuel level start to rise. When dealing w ith a 30 minute window, knowing now versus knowing in 5-10 minutes is a big deal (at least in terms of my stress level - FYI, I live out west were air ports are frequently more than 30 minutes apart).=0A=0AJon Finley=0AN314JF - Q2 - Subaru EJ22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www.fi nleyweb.net/Q2Subaru.aspx=0A =0A =0A=0A-----Original Message-----=0AFrom: " rampil" =0ASent: Tuesday, April 20, 2010 6:41am=0ATo: aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Re: Facet pu =0A=0AGood engineering principles favor measuring th e actual parameter=0Ayou want, rather than a surrogate, especially when the re is no=0Areliable one-to-one mapping of one to the other.=0A=0AIn the cas e of current draw, for example, overheating the coil or dirt=0Ain the mecha nism will probably change the current draw=0APressure downstream would depe nd on where the fill hose enters the =0Adownstream tank, if at the bottom, or at a positive hydrostatic head, the =0Apressure downstream of the pump w ill stay positive while there is fuel=0Ain the tank.=0A=0AWhat about measur ing fuel level in the feeding tank, is not that what you=0Areally want to m ake a decision with? When it reads zero, stop pumping?=0A=0A--------=0AIra N224XS=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matron ================0A=0A=0A=0A ________________________________ Message 5 _____________________________________ Time: 07:51:11 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Test --- Do Not Archive In a message dated ________________________________ Message 6 _____________________________________ Time: 07:58:18 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Morning Ira, I have what I consider to be relatively good fuel gauges in the tanks, but find that there is at least a ten to fifteen minute window between where the gauge says empty and it actually will be dry. I do not wish to turn the pump off too soon and have fuel in the tank that has not been used and I do not like to run the pump when it is not actually pumping fuel. It would be very nice to be able to verify the accuracy of the fuel gauge by noting when the pump stops pumping fuel rather than running the pump while dry for possibly an extra ten to fifteen minutes every time I utilize the auxiliary fuel tank. I do have excellent fuel use measuring capability and what I do now is note the fuel burned number when I turn on the pump and shut it off when the amount of fuel known to be in the tank has been burned. Nevertheless, it would be nice to know within seconds when the tank has run dry so that the pump could be turned off. I really would rather not be running the pump when it is not pumping fuel. Happy Skies, Old Bob In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time, ira.rampil@gmail.com writes: --> AeroElectric-List message posted by: "rampil" Good engineering principles favor measuring the actual parameter you want, rather than a surrogate, especially when there is no reliable one-to-one mapping of one to the other. In the case of current draw, for example, overheating the coil or dirt in the mechanism will probably change the current draw Pressure downstream would depend on where the fill hose enters the downstream tank, if at the bottom, or at a positive hydrostatic head, the pressure downstream of the pump will stay positive while there is fuel in the tank. What about measuring fuel level in the feeding tank, is not that what you really want to make a decision with? When it reads zero, stop pumping? -------- Ira N224XS ________________________________ Message 7 _____________________________________ Time: 10:35:34 AM PST US From: Mike Welch Subject: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Bob=2C Pardon me for butting in=2C but from my experience with certificated airp lanes=2C it is virtually impossible to get a field approval like you're aft er. I used to have a 1961 Cessna 172=2C with an O-300 Continental. On those hot mid-summer California days (100+)=2C my oil temps got well into the red on climbout!! I checked the accuracy of the gauge=2C and it was correct! Therefore=2C I wanted to add an oil cooler to my Cessna 172. It didn't c ome with one=2C but I could get a later model 172 oil cooler to fit. I sen t off my Form 337 to the local FSDO=2C and their first reaction was "NO!" Their attitude was "if it didn't come with one=2C it doesn't need one!!" I was irritated (to say the least)=2C and requested an appeal. They fina lly relented and said it would be okay. For crying out loud =2C it was jus t an oil cooler!! (all certified parts=2C too) My opinion is=3B there ain't no way you can legally add any kind of perma nent parts to modify to your fuel pump=2C fuel lines=2C or anything else=2C on a certificated airplane=2C without that approved 337. Just my opinion................. Mike Welch From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Morning Ira=2C I have what I consider to be relatively good fuel gauges in the tanks=2C bu t find that there is at least a ten to fifteen minute window between where the gauge says empty and it actually will be dry. I do not wish to turn the pump off too soon and have fuel in the tank that has not been used and I d o not like to run the pump when it is not actually pumping fuel. It would be very nice to be able to verify the accuracy of the fuel gauge b y noting when the pump stops pumping fuel rather than running the pump whil e dry for possibly an extra ten to fifteen minutes every time I utilize the auxiliary fuel tank. I do have excellent fuel use measuring capability and what I do now is note the fuel burned number when I turn on the pump and shut it off when the am ount of fuel known to be in the tank has been burned. Nevertheless=2C it would be nice to know within seconds when the tank has r un dry so that the pump could be turned off. I really would rather not be running the pump when it is not pumping fuel. Happy Skies=2C Old Bob In a message dated 4/20/2010 7:43:50 A.M. Central Daylight Time=2C ira.ramp il@gmail.com writes: Good engineering principles favor measuring the actual parameter you want=2C rather than a surrogate=2C especially when there is no reliable one-to-one mapping of one to the other. In the case of current draw=2C for example=2C overheating the coil or dirt in the mechanism will probably change the current draw Pressure downstream would depend on where the fill hose enters the downstream tank=2C if at the bottom=2C or at a positive hydrostatic head=2C the pressure downstream of the pump will stay positive while there is fuel in the tank. What about measuring fuel level in the feeding tank=2C is not that what you really want to make a decision with? When it reads zero=2C stop pumping? -------- Ira N224XS _________________________________________________________________ Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O N:WL:en-US:WM_HMP:042010_2 ________________________________ Message 8 _____________________________________ Time: 11:05:32 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Facet pumps: Energy vs. Flow Good Afternoon Mike, Believe it or not I do understand your frustration and the problems that are faced when dealing with the FAA. It is my opinion that the vast majority of the folks at FAA want to do a good job, but are so hamstrung with regulations and paper work that it is easier to just say no. However, I have had fairly good luck getting local approvals from my supervising FSDO. As I think we can all agree, each FSDO is a kingdom unto itself and what is easy to get approved at one office may be impossible at another. Nevertheless, I have gotten several local approvals here locally. I do hold an A&P with Inspection Authorization. It does help me know who I should present the data to and how the presentation should be made. In general, if we can think of a way to add something that has no chance of interfering with required equipment, the local approval has a better chance of being approved. Once again, the FAA has no obligation to ever issue a local approval. In fact, if an individual inspector does issue the approval, he is doing it on his own knowledge and is personally responsible for what happens. In many ways it is surprising that any FAA inspector ever issues a local approval. He/she has no obligation to do so. It is just a privilege he has been accorded. Failure to do so does not hurt his career at all, but making a dumb approval could end his career. Happy Skies, Old Bob In a message dated 4/20/2010 12:37:05 P.M. Central Daylight Time, mdnanwelch7@hotmail.com writes: Bob, Pardon me for butting in, but from my experience with certificated airplanes, it is virtually impossible to get a field approval like you're after. I used to have a 1961 Cessna 172, with an O-300 Continental. On those hot mid-summer California days (100+), my oil temps got well into the red on climbout!! I checked the accuracy of the gauge, and it was correct! Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't come with one, but I could get a later model 172 oil cooler to fit. I sent off my Form 337 to the local FSDO, and their first reaction was "NO!" Their attitude was "if it didn't come with one, it doesn't need one!!" I was irritated (to say the least), and requested an appeal. They finally relented and said it would be okay. For crying out loud , it was just an oil cooler!! (all certified parts, too) My opinion is; there ain't no way you can legally add any kind of permanent parts to modify to your fuel pump, fuel lines, or anything else, on a certificated airplane, without that approved 337. Just my opinion................. Mike Welch ________________________________ Message 9 _____________________________________ Time: 01:53:26 PM PST US Subject: AeroElectric-List: Re: switch breaker on ALT field From: "rckol" Switch breakers will function for this application. I have read conflicting reports about the long term reliability of these. Some folks end up tearing them out because they don't hold up and others have no trouble with them. Sorry, I don't have any brand specific recommendations. I am not going to use them. Dick -------- rck Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295024#295024 ________________________________ Message 10 ____________________________________ Time: 03:38:33 PM PST US Subject: AeroElectric-List: S704-1 on Hot Side of Firewall? From: "Noah" I requested the spec sheet for the S704-1 relay from B&C, and it is a Tyco T9A with an operating temp limit of 85C (185F). This seems a bit low for mounting in the engine compartment on the firewall. where I had been planning to mount it. I called B&C to ask them if they recommended mounting these in the engine compartment and the gentleman I spoke with was not sure - he recommended a post here. Anybody know what the firewall temps can climb to?? Anybody mounted one of these firewall forward in an RV and had problems? Or had it last 2000 hours without issue?? -------- Highest Regards, Noah Forden RV-7A Rhode Island Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295030#295030 ________________________________ Message 11 ____________________________________ Time: 08:30:35 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: S704-1 on Hot Side of Firewall? At 05:36 PM 4/20/2010, you wrote: > >I requested the spec sheet for the S704-1 relay from B&C, and it is >a Tyco T9A with an operating temp limit of 85C (185F). This seems a >bit low for mounting in the engine compartment on the firewall. >where I had been planning to mount it. I called B&C to ask them if >they recommended mounting these in the engine compartment and the >gentleman I spoke with was not sure - he recommended a post here. > >Anybody know what the firewall temps can climb to?? Anybody mounted >one of these firewall forward in an RV and had problems? Or had it >last 2000 hours without issue?? It will be fine. These devices and their close cousins are used under the hood of motor vehicles and they're fine. The various companies I've worked for have done numerous studies of temperature under the cowl and found that nothing gets really all that hot as long as it's not exposed to direct infra-red radiation from stacks (particularly turbochargers). I've seen some RG battery cases melted because they were too close to exhaust pipes. Bob . . . ________________________________ Message 12 ____________________________________ Time: 08:36:06 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: switch breaker on ALT field At 03:50 PM 4/20/2010, you wrote: > >Switch breakers will function for this application. > >I have read conflicting reports about the long term reliability of >these. Some folks end up tearing them out because they don't hold >up and others have no trouble with them. Sorry, I don't have any >brand specific recommendations. I am not going to use them. The mil-qualified sw/breakers are fine. Actually, the P&B W31 series are reasonably decent too. There's about 80K in service in Bonanzas and Barons since way back when . . . and yes, a few have failed in a way that put smoke in the cockpit . . . but those were the 30A devices that control electric prop de-ice. Obviously, you can't get the features in single switches of any kind that are offered in the progressive- transfer 2-pole toggles (2-10, 2-50, 2-70) but if your design goals don't require this feature, then the single switches will do. Now, having said that, I'm not sure I'd recommend the W31 used upstream of a crowbar ov protection system that I designed. I've not studied the trip dynamics of this device in that application. The miniature TI/Klixon style breakers have been paired with our crowbar ov systems by the thousands with good service histories. Bob . . . =================================== com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List =================================== cs.com" target="_blank">http://forums.matronics.com =================================== com/contribution" target="_blank">http://www.matronics.com/contribution =================================== ________________________________ Message 23 ____________________________________ Time: 05:42:50 PM PST US From: "Dennis & Anne Glaeser" Subject: AeroElectric-List: RE: RE: Designing a circuit question See my comments after the ----->'s below... RE: RE: Designing a circuit question From: Mike Welch I REALLY like your circuit design regarding the IvoProp motor. In fact I'm planning on building one seeing as how I have an IvoProp...with the motor. If I understand the process correctly by pushing the dpdt switch when the motor sees 6A current the LED will light up. Let go of the dpdt switch quickly and you're in like Flynn. -------> Yup! Not only does the LED illuminate, the current to the motor is limited, so it may stop before reaching the physical stop if twisting the blade is loading the motor enough. That's why I was asking about adjusting the trigger amperage. We don't want the circuit limiting the pitch too much. ----------------- Here's my question: would it be much of a challenge for the motor to lighten multiple LEDs (in both directions) as it cycles from 0 to 10A? Of course you'd want two separate circuits indicating if you're headed to flat pitch...or steep pitch or some method to insure you're twisting the prop in the correct direction you intended to. ----------> The light will come on whenever the trigger amperage is reached as you note above. Direction (toward high or low pitch) depends on which way the switch is moved. Bob's circuit sees current in the same direction all the time, the switch is where it is reversed for the motor. ---------------------- Wouldn't this design I'm asking about be essentially an analog version of a current meter? Example: say you're at zero pitch and you cycle toward steep pitch. As the motor's current draw increases it could light a 1A LED then a 2A LED a 3A LED etc etc. If a guy had this type of design he could routinely set his prop pitch to a known LED position to achieve maximum value of a variable pitch prop. He could adjust his engine and prop (LED) to a known performance characteristic.....i.e......engine rpm 4750 pitch in the steep direction #5 LED. --------> A number of IVO users have put an ammeter in the circuit to do what you suggest by simply reading the meter instead of watching LEDs. Direction is which way you move the switch, the ammeter works the same in both directions. ------------- Same process for the other prop twist. ----------> No, the current to the switch is always in the same direction. You'd have to put something on in the lines to the motor to be able to sense which way the motor is being driven. ------------- Dennis Glaeser ________________________________ Message 24 ____________________________________ Time: 06:33:58 PM PST US From: Robert Sultzbach Subject: Re: AeroElectric-List: Diode confusion Check the EAA.ORG website under hints for homebuilders electrical. They have a nice video with an instructor demonstrating exactly what you are asking about. It will clear things up for you. Bob S. Sent from my iPhone On Apr 21, 2010, at 19:41, Lincoln Keill wrote: Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab for my SD-8 relay control and thought -- "gee, maybe I better check this diode to make sure it's good before I do this" -- what could be simpler? Current flows from the non-band side of the diode to the band side, but not the other way (just like the schematic), right? Get out the multi-meter, set it to measure ohms. I put the red lead on the non-band side and the black lead on the band side and expect to see zero (or very little) resistance. Uh oh....infinite resistance...not good...do I have the leads reversed on the meter? Nope. I reverse the leads (red on band-side and black on non-band-side...expecting to see infinite resistance) and see...uh oh...3 milliohms. Now I'm really confused. I pull another diode out of the packet and repeat the test....same result. I check the heat-sinked bridge recitifier for the ebus regular feed...same result. I believe the chance that three different components turned out defective or mis-labeled are pretty remote and the chance that my knowledge of all things electric is (once again) in need of improvement. Perhaps I just don't understand how the multimeter works. My question: For a functioning diode, shouldn't current flow from the red lead of the multimeter when it's placed on the non-band side of the diode, to the black lead of the multimeter when it's on the band-side of the diode and indicate zero (or very little resistance)? Thanks to whoever can set me straight on this ridiculously simple concept. Do Not Archive Lincoln Keill RV-7A ________________________________ Message 25 ____________________________________ Time: 06:43:47 PM PST US From: Robert Sultzbach Subject: Re: AeroElectric-List: Diode confusion Check the EAA.ORG website under hints for homebuilders electrical. They have a nice video with an instructor demonstrating exactly what you are asking about. It will clear things up for you. Bob S. Sent from my iPhone On Apr 21, 2010, at 19:41, Lincoln Keill wrote: Getting ready to crimp a Radio Shack 1N5400 diode into a fast-on tab for my SD-8 relay control and thought -- "gee, maybe I better check this diode to make sure it's good before I do this" -- what could be simpler? Current flows from the non-band side of the diode to the band side, but not the other way (just like the schematic), right? Get out the multi-meter, set it to measure ohms. I put the red lead on the non-band side and the black lead on the band side and expect to see zero (or very little) resistance. Uh oh....infinite resistance...not good...do I have the leads reversed on the meter? Nope. I reverse the leads (red on band-side and black on non-band-side...expecting to see infinite resistance) and see...uh oh...3 milliohms. Now I'm really confused. I pull another diode out of the packet and repeat the test....same result. I check the heat-sinked bridge recitifier for the ebus regular feed...same result. I believe the chance that three different components turned out defective or mis-labeled are pretty remote and the chance that my knowledge of all things electric is (once again) in need of improvement. Perhaps I just don't understand how the multimeter works. My question: For a functioning diode, shouldn't current flow from the red lead of the multimeter when it's placed on the non-band side of the diode, to the black lead of the multimeter when it's on the band-side of the diode and indicate zero (or very little resistance)? Thanks to whoever can set me straight on this ridiculously simple concept. Do Not Archive Lincoln Keill RV-7A ________________________________ Message 26 ____________________________________ Time: 06:51:29 PM PST US From: Mike Welch Subject: RE: AeroElectric-List: RE: RE: Designing a circuit question Dennis=2C Upon close inspection of the current in Bob's design=2C yup=2C you're rig ht about the current direction. Back to my idea. I suppose the ammeter might not be too bad of a directi on to go=2C but I still like the idea of a line of 5-6 LEDs=2C which is an indication of the prop's motor current load. Would this be a simple circu it=2C and very importantly=2C can it be a modification to the one Bob came up with? I can sure see an advantage to a combo circuit.....one that show s you visually that you are increasing the current=2C and eventually the fi nal LED=2C indicating near max current? Mike Welch _________________________________________________________________ The New Busy is not the old busy. Search=2C chat and e-mail from your inbox .. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:O N:WL:en-US:WM_HMP:042010_3 ________________________________ Message 27 ____________________________________ Time: 08:07:46 PM PST US Subject: AeroElectric-List: Re: S704-1 on Hot Side of Firewall? From: "Noah" Thanks Bob. Prior to your response, I moved the battery bus and E-bus relay south of the firewall on my schematic. I think I like that better anyway. Roughly the same number of wires transiting the firewall feed-thru. Does require a fusible link on the battery bus feed however. -------- Highest Regards, Noah Forden RV-7A Rhode Island Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295213#295213 ________________________________ Message 28 ____________________________________ Time: 08:08:43 PM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Re: The Miracle Whip series antennae Keith, What kind of aircraft? Where did you mount? Did you have to run coax? Does it work with VHF comm and VOR signals? I've never heard of this antenna before. Inquiring minds want to know. Stan Sutterfield Folks; >From the 'for what it's worth' dept -- I bought a plane that had a standard Comant antenna mounted on the bottom on an almost all metal plane. Sitting on the ground, I was unable to receive weather. I replaced that antenna with a miracle whip placed in a small fiberglass portion of the plane at about the same distance from the ground. I was amazed at the results in reception and also the cleanliness of reception. Friends told me my radio coms were crystal clear. I am a happy Miracle Whip user. The antenna is also in one piece, so if you dont glue it in place, it will serve as a great rubber duck replacement for a handheld. -- Keith ________________________________ Message 29 ____________________________________ Time: 08:15:05 PM PST US Subject: AeroElectric-List: Alternator field feed - fuse vs. fusible link From: "Noah" I understand why a fusible link is specified in line with the 5A breaker for alternator field feed. The breaker is designed to trip when the regulator grounds the feed in case of bus overvoltage. And I understand that the fusible link protects the wire from the bus to the breaker from a dead short. But if you're using the B&C fuseblocks, why not just stick a 30A fuse in there in place of the fusible link? Seems like it would also be robust, the breaker would still trip in case of overvoltage, and you wouldn't need to fabricate a custom fusible link?? In my case I have several wires being ganged together at the fuseblock terminal and this approch would eliminate one of them! I know I must be missing something here, just don't know what! -------- Highest Regards, Noah Forden RV-7A Rhode Island Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295217#295217 ________________________________ Message 30 ____________________________________ Time: 08:39:05 PM PST US Subject: AeroElectric-List: Circuit Diagram From: "rckol" Some of you toiling to understand the whys and wherefores of the Z diagrams might also enjoy this bit of silliness: http://www.xkcd.com/730/ -------- rck Read this topic online here: http://forums.matronics.com/viewtopic.php?p=295219#295219 ________________________________ Message 31 ____________________________________ Time: 09:36:42 PM PST US From: Subject: RE: AeroElectric-List: Alternator field feed - fuse vs. fusible link The "dead short" on this circuit when (if) the crowbar circuit operates cou ld quite easily "blow" the 30 Amp fuse before or while tripping the 5A brea ker. The time constants for breakers and fuses are significantly different. To do as you suggest would work but at the risk of having to replace a fus e before being able to bring the alternator back on line. The suggested met hod has been well thought out and all failure modes taken into account. It' s the way it is for good reason. Just a quick anecdotal story to illustrate. Many moons ago in electric moto rs lab=2C a fellow student made a wiring error when connecting a motor for "plugging" it to a stop. (Plugging a motor involves removing the line power then shorting the motor to cause it to stop quickly) Long story short he c onnected the plugging relay across the three phase line instead of across t he motor. When the "stop" button was pressed=2C the 25 amp test bench break er tripped=2C the 125 amp lab supply breaker tripped=2C the 400 amp breaker supplying the whole floor of the school tripped=2C and the 800 amp main in coming breaker to the building tripped. Maybe unusual=2C but happened. Bob McC > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelec tric-list- > server@matronics.com] On Behalf Of Noah > Sent: Wednesday=2C April 21=2C 2010 11:11 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Alternator field feed - fuse vs. fusible link > > > I understand why a fusible link is specified in line with the 5A breaker for alternator > field feed. The breaker is designed to trip when the regulator grounds t he feed in > case of bus overvoltage. And I understand that the fusible link protects the wire from > the bus to the breaker from a dead short. But if you're using the B&C fu seblocks=2C why > not just stick a 30A fuse in there in place of the fusible link? Seems l ike it would also > be robust=2C the breaker would still trip in case of overvoltage=2C and y ou wouldn't need > to fabricate a custom fusible link?? In my case I have several wires bei ng ganged > together at the fuseblock terminal and this approch would eliminate one o f them! > > I know I must be missing something here=2C just don't know what! > > -------- > Highest Regards=2C > > Noah Forden > RV-7A > Rhode Island > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=295217#295217 > > > > > > > > _- > ======================== == > ======= > _- > ======================== == > ======= > _- > ======================== == > ======= > _- > ======================== == > ======= > > ________________________________ Message 32 ____________________________________ Time: 10:08:49 PM PST US Subject: Re: AeroElectric-List: Future of general aviation From: Paul Kuntz I've been an engineer and program manager at Boeing for thirty-two years, and am continually surprised to see how few of my fellow employees are actually interested in aviation. Yesterday I sat in a room with about thirty other engineers who are working on a new US Navy aircraft, for a get-acquainted session with the new manager of the 200-member team that is building the mission electronics system for that aircraft. We went around the room for everyone to discuss their background and their outside interests. I was the only person in the room, including the group manager, who expressed any interest at all in airplanes and flying. This has been a pattern throughout my career, but I do find that my experience as a pilot and aircraft builder has generated wide respect for my opinion on the way to approach or solve a problem. Boeing does acknowledge the value of pilot experience in its work force, and provides a subsidy of $500 for non-pilots on achieving first solo, and another $500 on achieving a Private Pilot rating. Nevertheless, there seem to be far too few real airplane enthusiasts among the employees of a company that is known primarily as a supplier of a very large portion of the world's fleets of commercial airliners, not to mention many military aircraft. I call daily on my lifelong experience building model aircraft, my 40+ years membership in EAA, my personal pursuit of commercial, multi-engine, instrument, glider and CFI ratings, and my hands-on building of two homebuilt aircraft. There's simply nothing to replace true passion for aviation in the pursuit of practical, useful solutions for the problems encountered in the development of the next generation of aircraft. We all need to contribute to the continuance of this legacy by supporting programs like Young Eagles, encouraging youth who express interest in what we do, participating in information exchange forums like this one, and never taking the privilege of flying for granted. Regards, Paul Kuntz http://www.pipistrelbuilders.com On Wed, Apr 21, 2010 at 8:54 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > nuckolls.bob@aeroelectric.com> > > At 12:29 PM 4/20/2010, you wrote: > Bob, > > Pardon me for butting in, but from my experience with certificated > airplanes, it is virtually impossible to get a field approval like you're > after. > > I used to have a 1961 Cessna 172, with an O-300 Continental. On those hot > mid-summer California days (100+), my oil temps got well into the red on > climbout!! I checked the accuracy of the gauge, and it was correct! > > Therefore, I wanted to add an oil cooler to my Cessna 172. It didn't come > with one, but I could get a later model 172 oil cooler to fit. I sent off > my Form 337 to the local FSDO, and their first reaction was "NO!" Their > attitude was "if it didn't come with one, it doesn't need one!!" > > I was irritated (to say the least), and requested an appeal. They finally > relented and said it would be okay. For crying out loud , it was just an > oil cooler!! (all certified parts, too) > > My opinion is; there ain't no way you can legally add any kind of > permanent parts to modify to your fuel pump, fuel lines, or anything else, > on a certificated airplane, without that approved 337. > > Just my opinion................. > > An opinion not without foundation. Without telling > stories on anyone, I can share that I attended a > meeting yesterday. This was a gathering of technically > competent, talented integrators of simple-ideas into > elegant solutions. They were stampeded into a "solution" > the crippled the capability of perfectly good system > just to cover a flight condition that was easily > managed . . . all in the name of achieving "FAA > certification". > > I pissed off some of the attendees . . . may > have lost future business for that customer. > > Present trends plotted into the future do not > bode well for our beloved airplanes and the > people who design, build and fly them. We > have ever increasing numbers of people who > do not design, build and fly demanding to run > the show . . . all in the cause of "making > airplanes safer". > > Bob . . . > > ________________________________ Message 33 ____________________________________ Time: 10:58:07 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Surface temperature sensor At 03:58 PM 4/21/2010, you wrote: > >Do Not Archive > >Thanks IRA, > >Yes, I'll do some digging. I was thinking about something with a flat >profile and perhaps a stick on for a flat surface. There must be >somebody putting out a device that can be fastened to a flat surface >that has two wires sticking out of it. We usually use a thermocouple wire and stick it to the surface with some epoxy. If you don't have a thermocouple reading instrument, you can rig a direct reading semiconductor sensor like the the LM285. It's powered up directly from your 14v system through a 10K resistor and reads directly in degrees Kelvin. It's in the shape of a plastic TO92 transistor with a flat side easily bonded to the surface of interest. You can read it's measurement directly on a multimeter where 2.75 volts is equal to 275 degrees K. Very handy for a quick-n-dirty look-see. Radio Shack and Harbor Freight both stock temperature reading multimeters based on type K thermocouple wire. Bob . . . ________________________________ Message 34 ____________________________________ Time: 11:06:15 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: RE: Designing a circuit question At 01:34 PM 4/21/2010, you wrote: >'Lectric Bob, > > I REALLY like your circuit design regarding the IvoProp > motor. In fact, I'm planning on building one, seeing as how I have > an IvoProp...with the motor. > > If I understand the process correctly, by pushing the dpdt > switch, when the motor sees 6 A current, the LED will light > up. Let go of the dpdt switch quickly, and you're in like Flynn. Yes, the motor will see pretty much full bus voltage until it's draw exceeds the set-point for the current limiter. The votlage to the motor is reduced at that point to maintain a max current equal to setpoint. If that value is too low, it can be increased by paralleling the .1 ohm reistor with additional resistors as I described earlier today. > > Here's my question: would it be much of a challenge for the > motor to lighten multiple LEDs (in both directions), as it cycles > from 0 to 10A? Of course, you'd want two separate circuits > indicating if you're headed to flat pitch...or steep pitch, or some > method to insure you're twisting the prop in the correct direction > you intended to. That's a given depending on your switch. It's a spring loaded center off with one direction for increased pitch and the opposite direction for flatter pitch. > Wouldn't this design I'm asking about be essentially an analog > version of a current meter? Example: say you're at zero pitch, > and you cycle toward steep pitch. As the motor's current draw > increases, it could light a 1A LED, then a 2A LED, a 3A LED, etc, etc. >Same process for the other prop twist. No, it doesn't work that way. This light comes on only when the motor stalls against the stop at either max or min pitch. It's not intended to be a pitch value indicator. > > If a guy had this type of design he could routinely set his prop > pitch to a known LED position to achieve maximum value of a > variable pitch prop. He could adjust his engine and prop (LED) to > a known performance characteristic.....i.e......engine rpm 4750, > pitch in the steep direction #5 LED. I doubt that exact pitch is that tightly associated with motor current. However, it wouldn't be too hard to build a constant speed controller not unlike that electro-mechanical prop-pitch controller on the old Bonanzas . . . except this one would work better. It would be slow . . . but it could be quite accurate. When you increased manifold pressure at some prop pitch setting, you would see an immediate increase in rpm but it would come back to the set-point a few seconds after the power increase. I'm fiddling with a variant of the circuit I published to convert it to a solid state breaker instead of current limiter. In this case, you wouldn't need any heat sink because the device would be in the current limited mode for a few tens of milliseconds. I'll see if I can publish that variant tomorro evening. Bob . . . ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.