---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 07/08/13: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:34 AM - Re: Re: Boeing switches (Jay Hyde) 2. 04:41 AM - Re: Trouble transmitting... (Mark Wesson) 3. 06:26 AM - Subject: Re: Jabiru alternator noise-what really causes (Chris) 4. 06:59 AM - Re: Subject: Re: Jabiru alternator noise-what really causes (Robert L. Nuckolls, III) 5. 07:10 AM - Choosing the switches for an RV-10 (Owen Baker) 6. 07:43 AM - Re: Choosing the switches for an RV-10 (Robert L. Nuckolls, III) 7. 08:22 AM - Re: Looking for (off topic) (Larry Mac Donald) 8. 09:17 AM - Interesting product (Eric Page) 9. 09:59 AM - Re: Low voltage indicator with dual alternators (Bill Watson) 10. 11:13 AM - Re: Jabiru alternator noise-what really causes it? (Jerry) 11. 11:42 AM - Re: Interesting product (Ralph Finch) 12. 01:05 PM - Re: Choosing the switches for an RV-10 (Paul Fisher) 13. 01:29 PM - Re: Low voltage indicator with dual alternators (Robert L. Nuckolls, III) 14. 01:39 PM - Re: Interesting product (Verso Electronics) ________________________________ Message 1 _____________________________________ Time: 01:34:01 AM PST US From: "Jay Hyde" Subject: RE: AeroElectric-List: Re: Boeing switches That is exactly what I will be doing once the aircraft is flying; testing how heavy the control forces are with the trim at either limit; on a 'step-by-step' basis until full travel is reached- then I can decide if any further circuitry is merited, or perhaps a change in the mechanical trim arrangement. That is what I like so much about OBAM aircraft; with a bit of careful observation and rational thinking we can determine and apply the solutions ourselves.. Jay -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: 05 July 2013 12:22 AM Subject: RE: AeroElectric-List: Re: Boeing switches --> At 01:05 PM 7/4/2013, you wrote: >--> > >Good argument Bob.... I use a switch on the panel to power the trim, >but that may be a bit far away for a quick reaction, before the trim >lurks all the way to the end. You would do well to deduce the severity of a trim runaway. Is the airplane controllable with full trim either up or down? How fast does the trim run with respect to pilot reaction times needed to deal with a runaway? Are there stops or limits to trim excursion necessary for the full range of CG envelopes or will the system produce more pitch authority than would ever be necessary for normal operations? In a Lear, at Mach cruise, the system is manually failed and the pilot is obligated to keep hands in the lap for 3 seconds. Only then can he move to deal with the situation. After achieving a stable, safe condition, recorded data is analyzed for busting limits on attitude, altitude and airspeed excursions. The exercise is repeated and trim speeds then adjusted until a sweat-free, runaway recovery is assured. The trim systems I've seen in some TC aircraft are so slow that unexpected trims under worst case conditions are no big deal. But what's the story for YOUR airplane? Yes, if trim speeds are brisk, trim authority high and you have good reason for not reducing them, then some form of inarguable override is indicated. Instructing the pilot to pull a breaker for taming a trim runaway is generally not acceptable . . . even panel mounted switche situated amongst other switches will get you frowns from the human factors guys. At the same time, find out just how much risk is associated with an uncontrolled trim event and see if that can be engineered out as opposed to stacking emergency ops hardware on top of the design. Bob . . . ________________________________ Message 2 _____________________________________ Time: 04:41:34 AM PST US From: "Mark Wesson" Subject: RE: AeroElectric-List: Trouble transmitting... Tom, This sounds like a problem I have on a regular basis with a perfect radio. If you are being handed off it is becuase you are exiting his area and entering the next. This usually puts you at the furthest point from both radios. I have this problem even flying IFR in some more remote places. A radio power output and SWR check are a good maintenance ckeck item anyway but I would not be too worrried about one event. Mark Wesson _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Tom Chapman Sent: Sunday, July 07, 2013 10:04 AM Subject: Re: AeroElectric-List: Trouble transmitting... Thanks Bob and Dave! I have a starting point now and will get going on it tomorrow... Tom ...reception is perfect ...transmit light on A200 illuminating ...my radio is being heard by ATC intermittently Where should I start troubleshooting? Given the long history of un-eventful and satisfactory performance, the first rocks to peek under are things most likely to have CHANGED. The first thing I would do is get an SWR/PWR meter and check both transmitter power output -AND- antenna SWR. Two things that might have changed is condition of the transmitter's power output stages or condition of the antenna and its feed line. Here's a good example of a tool for this task. http://tinyurl.com/k4t2pn9 We reviewed this product here on the List a couple of years ago. It's a great performer at a very reasonable price. Every EAA chapter ought to have one to lend to members. Problems like these yield only to quantifiable measurement. If you acquire one of these, you will want to acquire N-male to F-BNC adapters. http://tinyurl.com/ksmdxch and a short piece of good coax (about 2' long) with a BNC-Male on each end. http://tinyurl.com/cgr42l5 (scroll down to RB-142 Cable Assemblies) Lord Kelvin expressed it thusly: "When you can measure what you are speaking about, and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts advanced to the stage of science." Bob . . . ________________________________ Message 3 _____________________________________ Time: 06:26:43 AM PST US From: "Chris" Subject: Subject: Re: AeroElectric-List: Jabiru alternator noise-what really causes =9C Is the microphone jack electrically isolated from the airframe? Further, does it's ground wire route in parallel with mic audio and ptt lines back to the radio?=9D Not sure about the mic audio and ptt grounds but will check when I get back from holiday. We did isolate the jacks.Noise is the same whether its intercom or radio, only time it disappears is when we take the alternator out of the mix. =9C P.S. Where are the alternator and battery grounded? To the Forest=of=Tabs?=9D The battery is grounded on the engine firewall side to the forest of tabs, the alternator is case grounded to the engine, it has two leads from it that go to the regulator. These leads are twisted for their full length. It has been described as a dynamo more than an alternator, where the rectification takes place at the regulator? These two wires are carrying A/C as far as I can tell. Thanks for the input Chris ________________________________ Message 4 _____________________________________ Time: 06:59:03 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: Subject: Re: AeroElectric-List: Jabiru alternator noise-what really causes Is the microphone jack electrically isolated from the airframe? Further, does it's ground wire route in parallel with mic audio and ptt lines back to the radio? Not sure about the mic audio and ptt grounds but will check when I get back from holiday. We did isolate the jacks.Noise is the same whether its intercom or radio, only time it disappears is when we take the alternator out of the mix. Okay. The high probability condition is a ground loop that injects alternator noise directly into the microphone wiring. Where are the alternator and battery grounded? To the Forest=of=Tabs? The battery is grounded on the engine firewall side to the forest of tabs, the alternator is case grounded to the engine, it has two leads from it that go to the regulator. These leads are twisted for their full length. Hmmmm . . . the PM alternator should be totally isolated from ground. I.e. a pair of leads come off the ends of the winding and go directly to the rectifier/regulator. Does the R/R have a case connection? The only ones I am familiar with feature electronics that float completely within the case. It has been described as a dynamo more than an alternator, where the rectification takes place at the regulator? Yeah, the common vernacular speaks to the PM alternator as a 'dynamo'. Back in the early days of belt driven alternators for cars, the rectifiers and regulators were external too. These two wires are carrying A/C as far as I can tell. Check to make sure the R/R does not incorporate any kind of case ground. Consider an experiment to connect the R/R(+) lead directly to battery(+) at the contactor and R/R(-) lead directly to the forest of tabs. As microphones go, the voltage levels at the mic jack for an aviation mic is pretty high . . . hundreds of millivolts. To inject so strong a signal from the alternator into the mic circuitry suggests an extra-ordinary set of physics . . . especially since your alternator is so limited in output. I think we're going to find that something in the wiring is not as presently perceived. Bob . . . ________________________________ Message 5 _____________________________________ Time: 07:10:22 AM PST US From: "Owen Baker " Subject: AeroElectric-List: Choosing the switches for an RV-10 7/8/2013 Hello Carlos, You wrote: =9CFor the magnetos and starter, did everybody use the ACS combined keyed switch, or is it better to use 2 toggles and one push-button momentary starter switch?=9D Given the wiring complexity (confusion) and the widely published poor reliability of the ACS combined starter =93 magneto switch I am surprised that any amateur builder would even consider installing such a switch in the aircraft that he is building. OC 'O C' Baker says "The best investment you can make is the effort to gather and understand information." PS: A more ponderable choice is how to place the switches in the panel. Two schools of thought are: a) Scatter the switches about the panel in some manner that locates the switches close to the instrument or device being controlled (an ergonomic philosophy); or b) Place all (or as many is feasible) of the switches in close proximity so that at one glance one can tell if all switches are either ON or OFF (a visual domination philosophy). ============= Time: 02:38:19 AM PST US From: "Carlos Trigo" Subject: AeroElectric-List: Choosing the switches for an RV-10 Guys It's time to choose the switches for the RV-10 panel, and I wonder which ones are more popular between the RV-10 builders: For the Master and ALT field, have you used the Cessna split rocker or just 2 separate toggle switches? For the magnetos and starter, did everybody use the ACS combined keyed switch, or is it better to use 2 toggles and one push-button momentary starter switch? And for the lights and other electrical equipment, which has been the choice: the classic rocker switches or the color coded toggle switches? Thanks for your opinions, both in the technical and the functional aspects Carlos ________________________________ Message 6 _____________________________________ Time: 07:43:03 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Choosing the switches for an RV-10 > > >Given the wiring complexity (confusion) and the >widely published poor reliability of the ACS >combined starter ' magneto switch I am surprised >that any amateur builder would even consider >installing such a switch in the aircraft that he is building. > >OC Can you point me to the discussions about this product? Are reliability issues centered on any one feature of the design? This switch is a clone of the legacy Bendix/Gerdes product popularlized in the single-engine markets waaayyy back when. I think I recall seeing a twin that needed two-keys to go flying. I'm wondering if the problems are not centered on starter contactor currents. The FAA saw fit to mandate adding a diode to the circuit for airplanes that were being upgraded to modern, two-stage solenoid/contactors . . . when in fact, contact opening arcing was just the worst of stress . . . that 30A inrush was still there . . . a stress that the switch was never designed to manage. Bob . . . ________________________________ Message 7 _____________________________________ Time: 08:22:32 AM PST US Subject: Re: AeroElectric-List: Looking for (off topic) From: Larry Mac Donald Bob, I don't recall the name either. But, if you check with an elevator construction firm I'm sure they will have a name for this part. They use them to suspend the hoistway cables in the shaftway. Larry On Jul 6, 2013, at 4:29 PM, Robert L. Nuckolls, III wrote: > > I'd like to tap the collective experience of > the list in search of a gizmo that I don't even > know what to call it . . . > > I've seen cousins to the 'Chinese finger trap' that > could be slipped over a hose or large wire bundle. > One end of the 'trap' is fitted with a loop of small > cable . . . the same cable that makes up the > cylinder of the device. > > When placed over the hose/bundle and tensioned, > it grabs the outside surface over a large area > (essential damage free, low pressure) while > getting a grip on it. The work piece may then > be secured to some suspension point. > > I've seen them used to hold up drop cords suspended > from the ceiling. I've 'wandered' through the > Grainger and McMaster catalogs. I'd bet they have > 'em if I just knew the name of the beasts! > > Any ideas? > > > Bob . . . > > > > > ____________________________________________________________ 30-second trick for a flat belly This daily 30-second trick BOOSTS your body's #1 fat-burning hormone http://thirdpartyoffers.juno.com/TGL3141/51dad8de50aaf58dd0136st01duc ________________________________ Message 8 _____________________________________ Time: 09:17:54 AM PST US Subject: AeroElectric-List: Interesting product From: Eric Page All, I stumbled on this while looking for something else this morning and thought it might be of general interest. Looks like a pretty nifty product. http://www.panelpilot.com/ Cheers, Eric ________________________________ Message 9 _____________________________________ Time: 09:59:17 AM PST US From: Bill Watson Subject: Re: AeroElectric-List: Low voltage indicator with dual alternators On 7/6/2013 9:31 AM, Robert L. Nuckolls, III wrote: > > > >> I have the same setup and that's how it works. That is, the low >> voltage light simply monitors the voltage on the bus independent of >> alternator operation. Given that, I've wondered how a failed >> alternator would manifest itself. > > What architecture are we talking about? Z-12 or Z-14? > With independent buses for each alternator, the two > systems are normally operated with the cross-feed OPEN. > Each LV montior will tell the condition of it's respective > bus. It's a Z-14 > > >> - If failure was due to an overvoltage situation, the breaker would >> pop. Since I normally fly with the 2 buses interconnected > > Not recommended. I see what you mean. > >> I would expect the low voltage lights to remain off perhaps for the >> remainder of the flight. If one did come on because bus voltage >> dropped below the threshold, I would expect both to come on more or >> less simultaneously as long as the buses were interconnected. The >> only explicit indication of Alt failure would be the popped OV breaker. > > The design goals for Z-14 were two-fold. (1) > being able to parallel batteries for engine > cranking and (2) being able to share power between > systems in the event of an alternator failure. > > As you have deduced, running them in parallel > during normal operations has the potential for > obscuring failure of one of the alternators. My operational goals for the Z-14 included being able to run much of the panel on one battery while still having a fully charged battery for starting. The idea being that I wanted to be able to enter flight plans and even check weather before engine start. That's worked out well. I can connect the buses for starts if needed and that works well as well. However, I normally start with the buses separated because if I go parallel, the voltage drop causes my 3 MDFs to re-boot. > >> - Are there other modes of Alternator failure where there would be no >> explicit indication of failure? I'm thinking that a snapped belt >> would be an example. If loads and battery condition were such that >> the interconnected bus voltage stayed above the low volt threshold, >> there would be no explicit indication. Is that right? > > Yes. Another reason for running them independently > of each other for normal flight ops. With the crossfeed > closed, you have a Z-12 with dual batteries. Unless > one alternator is configured for stand-by operation by > incorporation of the appropriate regulator, then you > have two alternators in a paralleled mode of operation > controlled by regulators not designed for paralleling > (current management) of the two alternators. > I'll be going back to running independent. I know what got me started running with the buses interconnected but I lost track of what this robust configuration is designed to do. Thanks Bob! ________________________________ Message 10 ____________________________________ Time: 11:13:15 AM PST US From: Jerry Subject: Re: AeroElectric-List: Jabiru alternator noise-what really causes it? On 7/7/2013 9:02 AM, Chris wrote: > Hi All > A friend of mine has purchased a Zodiac 601 with a Jabiru engine. > The problem was originally lots of noise in the headsets. We rewired > the grounding , installed a forest of tabs on the firewall proper > ground strap to the engine. This cleared up all the noise and the > receive side of the radio is clear. The problem now is when > transmitting there is a loud side tone type noise along with the > verbal transmission, this noise gets worse with higher rpm.. The > transmission of voice is clear and fairly loud, but the hum that > accompanies it is very annoying to controllers. We disconnected the > alternator (dynamo) and the noise disappears. The alternator puts out > about 15 amps and is a bit on the small side for his application. > Jabiru suggests twisting the two alternator wires together which we > did and we also shielded them with no change. My question is what > actually causes this, and is there a way to get rid of it? It is a > Microaire radio, using the built in intercom. I did try a capacitor on > the main bus to ground with little or no effect. > I had the same problem with a Microair with an external intercom. Finally solved it by installing a Flightline 760. Jerry ________________________________ Message 11 ____________________________________ Time: 11:42:48 AM PST US From: Ralph Finch Subject: Re: AeroElectric-List: Interesting product Even after watching the demo it's unclear to me what this thing is supposed to do. For laying out my instrument panel I am using XPanel: http://www.xpanelsoftware.com/ On Mon, Jul 8, 2013 at 9:17 AM, Eric Page wrote: > > All, > > I stumbled on this while looking for something else this morning and > thought it might be of general interest. Looks like a pretty nifty product. > > http://www.panelpilot.com/ > > Cheers, Eric > > ________________________________ Message 12 ____________________________________ Time: 01:05:01 PM PST US Subject: Re: AeroElectric-List: Choosing the switches for an RV-10 From: Paul Fisher I installed the ACS keyed switch in a homebuilt I finished in 1990. Wiring was straight forward (Bob has a good diagram in the Z figures), and it has given me 23 years of reliable service. I put another one in my most recent project and it has been working fine for four years. So my personal experience does not support your statement below. It is simply part of the "security theater". As long as you are comfortable, toggle switches will work as well. YMMV, but the ACS switch has worked fine for me. Paul A. Fisher Q-200 N17PF - ~1,400 hours RV-7A N18PF- ~400 hours On Jul 8, 2013 9:16 AM, "Owen Baker" wrote: > 7/8/2013 > > Hello Carlos, You wrote: =93For the magnetos and starter, did everybody > use the ACS combined keyed > switch, or is it better to use 2 toggles and one push-button momentary > starter switch?=94 > > Given the wiring complexity (confusion) and the widely published poor > reliability of the ACS combined starter ' magneto switch I am surprised > that any amateur builder would even consider installing such a switch in > the aircraft that he is building. > > OC > > 'O C' Baker says "The best investment you can make is the effort to gathe r > and understand information." > > PS: A more ponderable choice is how to place the switches in the panel. > Two schools of thought are: a) Scatter the switches about the panel in so me > manner that locates the switches close to the instrument or device being > controlled (an ergonomic philosophy); or b) Place all (or as many is > feasible) of the switches in close proximity so that at one glance one ca n > tell if all switches are either ON or OFF (a visual domination philosophy ). > > ======================== ============== > > > Time: 02:38:19 AM PST US > From: "Carlos Trigo" > Subject: AeroElectric-List: Choosing the switches for an RV-10 > > Guys > > > It's time to choose the switches for the RV-10 panel, and I wonder which > ones are more popular between the RV-10 builders: > > > For the Master and ALT field, have you used the Cessna split rocker or ju st > 2 separate toggle switches? > > > For the magnetos and starter, did everybody use the ACS combined keyed > switch, or is it better to use 2 toggles and one push-button momentary > starter switch? > > > And for the lights and other electrical equipment, which has been the > choice: the classic rocker switches or the color coded toggle switches? > > > Thanks for your opinions, both in the technical and the functional aspect s > > Carlos > > * > =========== =========== =========== =========== > * > > ________________________________ Message 13 ____________________________________ Time: 01:29:44 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Low voltage indicator with dual alternators >My operational goals for the Z-14 included being able to run much of >the panel >on one battery while still having a fully charged battery for starting. The >idea being that I wanted to be able to enter flight plans and even >check weather >before engine start. That's worked out well. I can connect the >buses for starts >if needed and that works well as well. Okay, but consider the ENERGY needed to do these two tasks. Suppose you turn on three electro-whizzies for a total drain of 3A (a lot for solid state gizmos) and take 5 minutes to herd all the ducks into place. That 12v x 3A x 300 seconds for a total of 11,000 watt-seconds. Now, lets crank the engine at 200A x 12v x 10 seconds for a total of 24,000 watt-seconds. How much energy is available for use in a 18 a.h. SVLA battery? At a 3A rate will give it up over 5 hours at an average voltage of 11.5 for a total of about 650,000 watt-seconds. In other words, the task of conducting pre-flight activities and starting the engine are not big demands on a well maintained battery. > >However, I normally start with the buses separated because if I go >parallel, the voltage drop causes my 3 MDFs to re-boot. How much 'stuff' do you have to turn on before engine start? On the Beech products we used to offer a mini-ebus switch that would let you fire up a comm radio directly from the battery. Your comm radio probably needs 0.2A receive, and maybe 1.5A transmit. A long winded pre-flight activity might need 1000 watt-seconds. I'm thinking that the bus from which all your 'kitchen sink' accessories is powered also powers the comm radio and you have no way to power up the comm radio independently? You might want to consider moving a comm radio to a battery bus and adding . . . COMM RADIO . . . . . Check OFF . . . . to your shutdown checklist. Bottom line is that with two batteries on board, you've got perhaps a million watt-seconds to burn. Doing your starts in parallel will reduce relative abuse to the batteries and extend their service life. Letting the 'kitchen sink' accessories clock in after engine start may not be a significant delay in your departure plans. Bob . . . ________________________________ Message 14 ____________________________________ Time: 01:39:58 PM PST US Subject: Re: AeroElectric-List: Interesting product From: Verso Electronics Ralph, It's a video screen that can be customized through PC software to display tw o separate input voltages in various ways. The voltages can be expressions o f volts, amps, temps, pressures, quantities, etc. Pretty much anything that 's electronically measurable can be expressed as an analog voltage level and displayed on the screen in whatever format you choose (numbers, bar graph, n eedle-on-scale). Monitor bus voltage, alternator current, fuel qty, fuel pr essure, fuel flow, oil temp, oil pressure, manifold pressure, manifold temp, OAT, EGT, CHT. And so on. Choose any two and put them on a screen. Consider a DIY, poor man's engine monitor: Use a microcontroller to monitor and select the highest of four CHTs and highest of four EGTs to send to the display. Use the display's alarm output to light an LED or put a tone in y our headset. Eric On Jul 8, 2013, at 11:40 AM, Ralph Finch wrote: > Even after watching the demo it's unclear to me what this thing is suppose d to do. > > > On Mon, Jul 8, 2013 at 9:17 AM, Eric Page wrote: >> >> http://www.panelpilot.com/ ------------------------------------------------------------------------------------- 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.