---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 07/22/05: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:09 AM - Re: Tach source for EIS () 2. 05:46 AM - Re: Re: Tach source for EIS (John Swartout) 3. 06:16 AM - Re: Cherokee bouncing loadmeter (Lloyd, Daniel R.) 4. 07:43 AM - Re: alternate air conditioning (Dave Morris) 5. 08:47 AM - Re: alternate air conditioning (al.herron@Aerojet.com (Herron, Al)) 6. 08:54 AM - Re: Re: Tach source for EIS (Robert L. Nuckolls, III) 7. 09:37 AM - Slow starter (Charlie Burton) 8. 11:19 AM - Re: "P" lead length (John Schroeder) 9. 11:22 AM - Re: Re: Tach source for EIS (DonVS) 10. 02:29 PM - Best architecture for two alternator all-electric 912S Kitfox (Jon Goguen) 11. 03:25 PM - Re: Cherokee bouncing loadmeter (jdalton77) ________________________________ Message 1 _____________________________________ Time: 03:09:34 AM PST US From: Subject: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: John: I can save you a lot of trouble. What is your tack drive doing on the back of your engine? Nothing and you are likely going to have to buy a cover $10 for it. Well for $30 or $40 you can forget it and always measure RPM off the mechanical drive. It does not matter what your ignition is doing, which is the way it should be. Get a UMA tack drive. It is small and works real well. I recall mine put out 2 pulses per revolution of the tack drive. The tack drive ratio is 0.50:1, meaning it goes around only once for every two revs of the crank; I recall the EIS Tack setting is (1). http://www.umainstruments.com/1a3tsu.htm The thing works perfect and needs a 5V max power supply to tickle the EIS. Trying to switch between left or right ignition and switch your tack source is a pain, and can be done with some switching. Most don't bother and select just one side to connect to the EIS and accept a zero reading on a mag check with that side off. KEEP IT SIMPLE. I would not screw too much with connections to the brain box of your electronic ignition. Most people find simple toggle switch works well for electronic ignition. I assume you have a way to kill you P-mag after it is running? From what I understand it is self-sustaining after start-up? Good luck George PS Westach makes a tack drive as well as Van's aircraft sells one but it is bulky. I like the UMA for being compact. Time: 08:59:56 PM PST US From: "John Swartout" Subject: AeroElectric-List: Tach source for EIS --> AeroElectric-List message posted by: "John Swartout" Bob and others: The tachometer function on my Grand Rapids Technologies Engine Information System uses input from the electronic ignition (dual P-mags). It only accepts one input. Should I wire only one of the P-mags to the EIS, or both? That is, is there any reason to run a wire from each of the ignitions with a switch to select which one supplies rpm data to the EIS? Thanks. John ________________________________ Message 2 _____________________________________ Time: 05:46:10 AM PST US From: "John Swartout" Subject: RE: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "John Swartout" George, does that UMA tack drive convert mechanical to electronic to supply the EIS? 5 volts is sort of odd. How do you supply 5 volts to yours? I'll be using toggle switches per Z13-8 for the Pmags, so can turn off either one at any time. John -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of gmcjetpilot@yahoo.com Subject: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: John: I can save you a lot of trouble. What is your tack drive doing on the back of your engine? Nothing and you are likely going to have to buy a cover $10 for it. Well for $30 or $40 you can forget it and always measure RPM off the mechanical drive. It does not matter what your ignition is doing, which is the way it should be. Get a UMA tack drive. It is small and works real well. I recall mine put out 2 pulses per revolution of the tack drive. The tack drive ratio is 0.50:1, meaning it goes around only once for every two revs of the crank; I recall the EIS Tack setting is (1). http://www.umainstruments.com/1a3tsu.htm The thing works perfect and needs a 5V max power supply to tickle the EIS. Trying to switch between left or right ignition and switch your tack source is a pain, and can be done with some switching. Most don't bother and select just one side to connect to the EIS and accept a zero reading on a mag check with that side off. KEEP IT SIMPLE. I would not screw too much with connections to the brain box of your electronic ignition. Most people find simple toggle switch works well for electronic ignition. I assume you have a way to kill you P-mag after it is running? From what I understand it is self-sustaining after start-up? Good luck George PS Westach makes a tack drive as well as Van's aircraft sells one but it is bulky. I like the UMA for being compact. Time: 08:59:56 PM PST US From: "John Swartout" Subject: AeroElectric-List: Tach source for EIS --> AeroElectric-List message posted by: "John Swartout" Bob and others: The tachometer function on my Grand Rapids Technologies Engine Information System uses input from the electronic ignition (dual P-mags). It only accepts one input. Should I wire only one of the P-mags to the EIS, or both? That is, is there any reason to run a wire from each of the ignitions with a switch to select which one supplies rpm data to the EIS? Thanks. John ________________________________ Message 3 _____________________________________ Time: 06:16:11 AM PST US Subject: RE: AeroElectric-List: Cherokee bouncing loadmeter From: "Lloyd, Daniel R." --> AeroElectric-List message posted by: "Lloyd, Daniel R." My '68 140 also has the same issue, but it is not consistent, sometimes it bounces, then it will go several flights without presenting, then everyday for a week. Weird. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of jdalton77 Subject: AeroElectric-List: Cherokee bouncing loadmeter --> AeroElectric-List message posted by: "jdalton77" My 1973 Cherokee 140 suffers from the "bouncing" load meter problem. Load meter jumps to the right in a rhythm that I think is related to the strobes but seems to happen even when the light is off. It's been like that since I bought the plane a few years back. I've heard a lot of "reason" for this to happen - but no consistent story. There must be a real answer .... -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: Zeftronics vs B&C --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" --> At 06:52 AM 7/21/2005 -0800, you wrote: >--> AeroElectric-List message posted by: "Peter Mather" >--> > >Bob > >The new rev A version appears to include LV unless I'm mis-interpreting >the spec. I've looked the spec sheet over at: http://www.aeroelectric.com/Mfgr_Data/Zeftronics/R15V00RevA-PIT.pdf The way this is set up, I believe that "low volts" is inferred by noting alternator shutdown. The low volts sensor is not an independently powered monitor of actual bus voltage. The Zeftronics implementation seems to be a more sophisticated version of the alternator "idiot light" of years gone by. I suspect the regulation and ovp features are just fine. I'd still recommend a separate LV Warning system of some variety. Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:43:07 AM PST US From: Dave Morris Subject: Re: AeroElectric-List: alternate air conditioning --> AeroElectric-List message posted by: Dave Morris We looked at using these chips 20 years ago to cool the inside of a computer cabinet without requiring large cooling fans and holes (that let RFI out). Their power consumption was what made us give up. Dave Morris At 07:18 PM 7/21/2005, you wrote: >--> AeroElectric-List message posted by: Dj Merrill > > >Mark Cochran wrote: > > > So the 300 watts works out to about 21 Amps, is that right? Might work with > > a low-moderate heat load in the cockpit, but probably would take a while to > > achieve a large delta T. > > Hmmm - perhaps might not be enough to cool the entire >cabin, but maybe it might be good enough just to be able to >blow some cool air on the pilot, and maybe the passenger too. > >-Dj > >do not archive > >-- >Dj Merrill >Sportsman 2+2 Builder #7118 > >"TSA: Totally Screwing Aviation" > > ________________________________ Message 5 _____________________________________ Time: 08:47:17 AM PST US From: al.herron@Aerojet.com (Herron, Al) Subject: Re: AeroElectric-List: alternate air conditioning --> AeroElectric-List message posted by: al.herron@Aerojet.com (Herron, Al) Interesting idea. There is a web site for Peltier chips: http://www.peltier-info.com/info.html. These things are normally used for small-scale cooling of electronic equipment. According to the website, the Peltier chips are not very efficient and "draw amps of power". Of course, what a computer manufacturer considers inefficient might be nothing compared to a mechanical compressor setup. Somebody figure this out and call me back when you have a $39.95 unit I can plug into my plane! ; ) ________________________________ Message 6 _____________________________________ Time: 08:54:39 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" George, Excellent answer. Long before electronic tachs came along, we had a single speedometer cable coming of the back of the engine which drove the instrument on the panel. Electronic tachs have been a pain in the arse from day-one in that every new design took a slightly different approach to processing magneto signals and to make matters more difficult, every new electronic ignition offered what the designer believed was the elegant solution for data output to everyone else's tachometers. John's question raises a fundamental issue about how NECESSARY is a tachometer for the purpose of safely operating the airplane? I had a boss who took the company Bonanza on a cross-country trip and found that the tach was dead when he prepared to return from an airport about 150 miles away. He called a mechanic to fly out and fix his airplane (tach cable was unscrewed from the back of the engine and fell off). But just suppose one is in a similar situation with an electronic tach failure. How does this condition introduce new risk with respect to flying the airplane home sans tach? I'll suggest little or no risk. In the case of the A36, we know that the governor prevents operation above red-line. Operation at red-line is in the POH as a permissible rpm setting for cruise operations. If your airplane needs to run slower, give the prop knob a few twists and slow it down. Then continue the flight. Fixed pitch airplanes may be capable of exceeding red-line in level flight, fine . . . make a normal take off and bring throttle back till the engine sounds more relaxed. Set up for cruise and then adjust power for, say 5-10 kts below your normal cruise speed. Then you KNOW that the engine is at some point below published limits. My point is that a tachometer is used for PRECISE adjustment of conditions that produce the desired power setting. However, safe operation of the airplane can be accomplished over a huge range of power settings, none of which are stressful to the engine. With some simple observations and knowledge of how the airplane operates, one can very safely launch, cruise and land sans tachometer without adding risk. Therefore, I'll suggest that supplying an electronic tach with a signal from one of two electronic ignitions does not represent an incremental step up in risk for getting the airplane home should that particular signal path become unavailable. If it were my airplane, I'd hook up to one of the two ignition systems and quit worrying about it. Bob . . . >John: > >I can save you a lot of trouble. What is your tack drive doing on the back >of your engine? Nothing and you are likely going to have to buy a cover >$10 for it. Well for $30 or $40 you can forget it and always measure RPM >off the mechanical drive. It does not matter what your ignition is doing, >which is the way it should be. > >Get a UMA tack drive. It is small and works real well. I recall mine put >out 2 pulses per revolution of the tack drive. The tack drive ratio is >0.50:1, meaning it goes around only once for every two revs of the crank; >I recall the EIS Tack setting is (1). http://www.umainstruments.com/1a3tsu.htm > > >The thing works perfect and needs a 5V max power supply to tickle the EIS. > >Trying to switch between left or right ignition and switch your tack >source is a pain, and can be done with some switching. Most don't bother >and select just one side to connect to the EIS and accept a zero reading >on a mag check with that side off. KEEP IT SIMPLE. I would not screw too >much with connections to the brain box of your electronic ignition. Most >people find simple toggle switch works well for electronic ignition. > >I assume you have a way to kill you P-mag after it is running? From what I >understand it is self-sustaining after start-up? > >Good luck George > > >PS Westach makes a tack drive as well as Van's aircraft sells one but it >is bulky. I like the UMA for being compact. > > >--> AeroElectric-List message posted by: "John Swartout" > > >Bob and others: > >The tachometer function on my Grand Rapids Technologies Engine >Information System uses input from the electronic ignition (dual >P-mags). It only accepts one input. Should I wire only one of the >P-mags to the EIS, or both? That is, is there any reason to run a wire >from each of the ignitions with a switch to select which one supplies >rpm data to the EIS? Thanks. > >John ________________________________ Message 7 _____________________________________ Time: 09:37:38 AM PST US From: "Charlie Burton" Subject: AeroElectric-List: Slow starter --> AeroElectric-List message posted by: "Charlie Burton" I have a condition in my O-360 Glastar that puzzles me. I can turn the key switch (Aircraft Spruce) to START and the engine starts to turn but at a slow rate like a low battery, high compression, too small a battery cable, etc. The strange part is that I just let go of the key and then try it again and the engine turns over very nicely and starts on the first revolution through. I have one mag on the left side and a Lightspeed ignition on the right. Any ideas? Charlie Burton & N331Fox ________________________________ Message 8 _____________________________________ Time: 11:19:17 AM PST US Subject: Re: AeroElectric-List: "P" lead length From: "John Schroeder" --> AeroElectric-List message posted by: "John Schroeder" Bob - Thanks for the diagram. After a good night's sleep and some study of the diagram, we concluded that the mags were indeed wired OK. We did disconnect the leads and ground shields to check for shorts. The problem was in the test plan!! You gotta put the meter in line and not across the lines! Thanks for the help. John > > See http://www.aeroelectric.com/PPS/Engine/Ignition/TogMagSw.pdf > > Try disconnecting the switch leads entirely. You may have > shorted wiring between the switch and the magneto. > > Bob . . . > ________________________________ Message 9 _____________________________________ Time: 11:22:52 AM PST US From: "DonVS" Subject: RE: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "DonVS" John, You can't do it with the device that George recommended. Both of your mag drive holes are in use. You only need one lead to the EIS from a single PMAG. The rpm reading will come through even with the PMAG shut off. This is assuming that you have the new PMAG with the green wire for tach drive. Don -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of gmcjetpilot@yahoo.com Subject: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: John: I can save you a lot of trouble. What is your tack drive doing on the back of your engine? Nothing and you are likely going to have to buy a cover $10 for it. Well for $30 or $40 you can forget it and always measure RPM off the mechanical drive. It does not matter what your ignition is doing, which is the way it should be. Get a UMA tack drive. It is small and works real well. I recall mine put out 2 pulses per revolution of the tack drive. The tack drive ratio is 0.50:1, meaning it goes around only once for every two revs of the crank; I recall the EIS Tack setting is (1). http://www.umainstruments.com/1a3tsu.htm The thing works perfect and needs a 5V max power supply to tickle the EIS. Trying to switch between left or right ignition and switch your tack source is a pain, and can be done with some switching. Most don't bother and select just one side to connect to the EIS and accept a zero reading on a mag check with that side off. KEEP IT SIMPLE. I would not screw too much with connections to the brain box of your electronic ignition. Most people find simple toggle switch works well for electronic ignition. I assume you have a way to kill you P-mag after it is running? From what I understand it is self-sustaining after start-up? Good luck George PS Westach makes a tack drive as well as Van's aircraft sells one but it is bulky. I like the UMA for being compact. Time: 08:59:56 PM PST US From: "John Swartout" Subject: AeroElectric-List: Tach source for EIS --> AeroElectric-List message posted by: "John Swartout" Bob and others: The tachometer function on my Grand Rapids Technologies Engine Information System uses input from the electronic ignition (dual P-mags). It only accepts one input. Should I wire only one of the P-mags to the EIS, or both? That is, is there any reason to run a wire from each of the ignitions with a switch to select which one supplies rpm data to the EIS? Thanks. John ________________________________ Message 10 ____________________________________ Time: 02:29:47 PM PST US From: Jon Goguen Subject: AeroElectric-List: Best architecture for two alternator all-electric 912S Kitfox --> AeroElectric-List message posted by: Jon Goguen We've just decided to commit to an all-electric system, in part because we're convinced it's more reliable than vacuum, but also because a second alternator to supplement the built-in PM alternator on the 912S will make the energy budgeting less critical. I think we could make it work with original alternator only, but would need to go to LED position lights and take a series of other power efficiency measures. On the whole, the redundancy of the second alternator seems best, and will get the project completed more quickly: we're determined to be in the air this fall. We plan to use an SD-20 on the vacuum pump pad. I've been given figures ranging from 12-17 amps as reasonable expectations from the SD-20 in this installation, and figure I can count on a conservative 30 amps from both alternators in combination. I'm looking for recommendations regarding the most reasonable architecture for this combination. Two batteries or one? A big one and a little one? Both alternators on line all the time? I've read the 'Connection (don't know my Z-numbers yet without looking and don't have the book handy), but it's clear that several choices are possible. Anyone see a strong reason to favor one arrangement for our proposed alternator combination? We do plan eventual IFR operation, (Garmin 300XL IFR GPS/Com, one Nav radio, VAL single-hole ILS system, and electric gyros, supplemented with the an Anywhere map system including weather). Thanks in advance for any and all suggestions. We had already acquired much of the vacuum stuff (pump, regulator, and gyros) so now I need to get the electric versions. Any suggests regarding sources for cost-effective AI and DG would also be welcome. I will be at OshKosh from Thursday evening through Sunday AM, and hope to do some some to complete the equipment list. (If you have any interest in the vacuum stuff, enquiries are welcome.) Jon Jon Goguen jon.goguen@umassmed.edu Central Massachusetts Kitfox Series V Rotax 912S / N456JG (reserved) Complete except for electrics and avionics ________________________________ Message 11 ____________________________________ Time: 03:25:17 PM PST US From: "jdalton77" Subject: RE: AeroElectric-List: Cherokee bouncing loadmeter --> AeroElectric-List message posted by: "jdalton77" I tried that but unfortunately it still happens. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of EuropaXSA276@aol.com Subject: Re: AeroElectric-List: Cherokee bouncing loadmeter --> AeroElectric-List message posted by: EuropaXSA276@aol.com In a message dated 7/21/2005 9:31:35 PM Central Standard Time, jdalton77@comcast.net writes: My 1973 Cherokee 140 suffers from the "bouncing" load meter problem. Load meter jumps to the right in a rhythm that I think is related to the strobes but seems to happen even when the light is off. My 140E had the same problem. Very common problem. Fixed it by installing a new voltage regulator. Brian Skelly Texas Europa # A276 TriGear See My build photos at: http://www.europaowners.org/BrianS