---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 01/27/08: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:46 AM - Circuit breaker polarity (Greg Young) 2. 06:01 AM - Re: Circuit breaker polarity (rampil) 3. 08:52 AM - Re: Mono Isolation Amp - Where to get circuit board? (Robert L. Nuckolls, III) 4. 09:03 AM - Re: Voltage drop under load (Robert L. Nuckolls, III) 5. 11:06 AM - Re: Circuit breaker polarity (Robert L. Nuckolls, III) 6. 12:54 PM - Dumb questions (MaxNr@aol.com) 7. 01:20 PM - Power Board on EBay (h&jeuropa) 8. 01:26 PM - LEDs at 24volts? (Dawson-Townsend,Timothy) 9. 02:06 PM - Re: Dumb questions (jon@finleyweb.net) 10. 02:25 PM - Re: Dumb questions (Richard Girard) 11. 02:56 PM - Re: LEDs at 24volts? (rampil) 12. 03:01 PM - Z13-8 N error ? (Jeff Page) 13. 06:22 PM - LEDs at 24volts? (Ralph Hoover) 14. 07:38 PM - Re: Z13-8 N error ? (Robert L. Nuckolls, III) 15. 08:08 PM - Re: Circuit breaker polarity (Greg Young) 16. 08:10 PM - TNC connections (Jeffrey W. Skiba) 17. 10:09 PM - Z13-8 N P-Mags (Jeff Page) ________________________________ Message 1 _____________________________________ Time: 02:46:32 AM PST US From: "Greg Young" Subject: AeroElectric-List: Circuit breaker polarity I am rewiring my Navion panel using busses with Potter-Brumfield W31 switch breakers and Klixon 7277 c/b's. I put the P-B buss bar on the bottom following their Load-Line labeling but put the Klixon bar on top to ease access to the load terminals. My IA neighbor (not my supervising IA) tried to tell me it was backward but I had already checked and there is no labeling on the Klixon c/b's. I see no intuitive reason it should care about polarity but then I don't have a real understanding of their inner workings. Did I miss something? Does polarity matter for the Klixons? If so, I can change my buss. If not, why does P-B label their units (it's also on their W23 c/b's?) Is it real or just a case of eliminating choice? Thanks for the education. Regards, Greg Young ________________________________ Message 2 _____________________________________ Time: 06:01:21 AM PST US Subject: AeroElectric-List: Re: Circuit breaker polarity From: "rampil" Breakers have no polarity. Element heating occurs in either direction! -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=160648#160648 ________________________________ Message 3 _____________________________________ Time: 08:52:18 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Mono Isolation Amp - Where to get circuit board? At 04:55 AM 1/24/2008 -0800, you wrote: > > >I am adding a second radio to a plane that has no room for a full audio >panel without making a whole new panel. I am going to route two coms and >one marker beacon to the intercom. I have speced out the switched and >dome a wiring diagram. I looked at the Isolation Amp at the AeroElectric >web site. However, under parts, I don't see where I can order the circuit >board to make the amp (part no 9009-301-2A). > >Where do I get one? I've had a lot of requests for this item and I'm in the process of placing it back on the website order form. I'll try to get this done in the next few days. I've been out of town for a week and have some taller fires to beat down first. Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:03:54 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Voltage drop under load At 06:52 PM 1/24/2008 -0500, you wrote: > >Yes voltage starts to sag as the alternator output starts to lag demand. >Quick math suggests that your alternator is working properly. (100 watts >divided by 13.3 volts is about 7.5 amps per 100 watt load) My alternator >can handle all loads but the voltage will drop a bit if I pull the >throttle to idle on approach. No big deal if the battery helps out for a >few dozen seconds on final approach. In cruise my taxi lights wig wag >which halves the current draw. >Ken > >Bill Bradburry wrote: >> >> I noticed today that my voltage would drop from about 14.5 volts down to >>13.3 volts when I turned all my lights on. That is two 100W landing, two >>100W taxi, position, and strobe lights. >>I made sure that I had plenty of rpm to be certain that the alternator was >>putting out its max. The alternator is rated at 55A. >>Is it possible that I am pulling more amps than the alternator can handle? >>Is the drop of voltage an indicator of this? >>What should be the size of the B lead wire for a 55A alternator? >>Thanks, >>Bill B 13.3 is TOO low. You need to put a temporary lead wire on the alternator's b-lead terminal and bring it into the cockpit for attaching a voltmeter. You MAY find that the alternator voltage at the b-lead is holding up just fine and that your wiring is too small . . . i.e. accounts for the drops under load that you've observed. I recommend 4AWG minimum for all the "fat" wires in the airplane. There's so little of it that weight deltas are insignificant . . . but 4AWG or larger makes for very solid voltage regulation at all loads. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 5 _____________________________________ Time: 11:06:53 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Circuit breaker polarity At 04:39 AM 1/27/2008 -0600, you wrote: >I am rewiring my Navion panel using busses with Potter-Brumfield W31 >switch breakers and Klixon 7277 c/b's. I put the P-B buss bar on the >bottom following their Load-Line labeling but put the Klixon bar on top to >ease access to the load terminals. My IA neighbor (not my supervising IA) >tried to tell me it was backward but I had already checked and there is no >labeling on the Klixon c/b's. I see no intuitive reason it should care >about polarity but then I don't have a real understanding of their inner >workings. Did I miss something? Does polarity matter for the Klixons? If >so, I can change my buss. If not, why does P-B label their units (it's >also on their W23 c/b's?) Is it real or just a case of eliminating choice? >Thanks for the education. Intuitively, the physics of a series-connected heat-tripped, switch do not suggest a reason why the breaker would care which way electrons flow through it . . . and in particular, AC system breakers where electrons are known to turn around and run the other direction 120 times a second! You've already had some good responses but I'll take this opportunity to elaborate. Not all breakers are rudimentary . . . i.e. a simple spring-loaded, heater-tripped latch holding a set of single or double-break contacts closed. Breakers can be had with auxiliary switches, indicator lights, voltage sense coils, and all manner of enhancements where proper function of the enhancement depends on a connection to power being available even when the breaker is open. Obviously, some third terminal is necessary for an enhancement to function, this is sometimes an obvious connection, or perhaps it gets hooked up through the mounting. In any case, it's not uncommon for a manufacturer to use common tooling to mold a breaker housing for all versions, hence you often see the word "load", "line" or both formed right next to the breaker's terminals . . . I've asked several tech reps for breakers and except for enhanced breakers, orientation in the system doesn't matter. Interestingly enough, if an electrician encounters "line" and/or "load" labels on a breaker, he'll wire it up that way whether it matters or not. And I suspect many aviation techs do too . . . not because the physics matters but because some inspector who doesn't know any better can be counted on to insist that the protocols be followed. The only time I've encountered this as a "problem" is when a builder finds it convenient to fabricate a two-row bus-bar and take load feeders off opposite ends of the breaker. When they come stamped with a breaker rating, they look pretty funky with one row upside-down in their holes! Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 6 _____________________________________ Time: 12:54:55 PM PST US From: MaxNr@aol.com Subject: AeroElectric-List: Dumb questions I have been sitting in the back row on this list, hoping to learn something. I was born without any electronic genes. I am building an all metal light sport plane.(Zenith) Right or wrong, I developed the habit (over five decades of personal, military and commercial flying) of listening to broadcast radio on the ADF. I'm thinking that I need to install an of the shelf automobile radio in my project. No second hand Ebay ADF's. My two questions are: Will I fry the radio if I use only a headset and no speakers? About the antenna. I know that I should mount it vertically, but it must withstand airspeed excursions to Vne (156kts/180mph) without going L shaped. I've come up with somehow jamming it inside the canopy, or insulating it and mounting against the landing gear, or inside some kind of tubular mast on the belly. I did come across a NOS Volkswagen telescoping antenna in my shop. It would be great if that Lyc carburetor turns up again the same way. Somebody stop me if I'm on the wrong track. This isn't the most pressing problem out there, but all suggestions are appreciated. Bob Dingley ************** Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 ________________________________ Message 7 _____________________________________ Time: 01:20:36 PM PST US Subject: AeroElectric-List: Power Board on EBay From: "h&jeuropa" Check out Item # 120215336354 or search for "Power Board" for an auction for a Blue Mountain Avionics Power Board. Jim Butcher Read this topic online here: http://forums.matronics.com/viewtopic.php?p=160699#160699 ________________________________ Message 8 _____________________________________ Time: 01:26:54 PM PST US Subject: AeroElectric-List: LEDs at 24volts? From: "Dawson-Townsend,Timothy" I have my reasons, so let's not get into that, but we're building a 24/28 volt airplane. Question: Can I take an LED with built-in resistor for 12 volt operation (as bought at Radio Shack) and run it at 24 volts? On the bench it seems to operate fine. Even if it reduces LED life somewhat, with the insane life that LEDs have anyway, and an application as warning light that is intermittant at best, maybe it will do fine. Thoughts? TDT RV-10 40025 ________________________________ Message 9 _____________________________________ Time: 02:06:46 PM PST US Subject: RE: AeroElectric-List: Dumb questions From: jon@finleyweb.net =0AHi Bob,=0A=0A =0A=0AMight I suggest you take a look at satellite radio - like XM (http://www.xmradio.com) or Sirius? I've been flying with an XM s etup (Roady XL) and love it. I can move it from car to airplane to house o r listen on my computer/Internet, in-flight station reception doesn't fade out every 15 minutes (as I fly away from a station), and the antenna is a l ittle tiny thing that is mounted inside my airplane (zero drag). It does r equire a subscription so is not free. In my plane, I just connect the radi o output to my intercom music input.=0A=0A =0A=0AJon=0A=0A=0A-----Original Message-----=0AFrom: MaxNr@aol.com=0ASent: Sunday, January 27, 2008 3:49pm =0ATo: aeroelectric-list@matronics.com=0ASubject: AeroElectric-List: Dumb q uestions=0A=0AI have been sitting in the back row on this list, hoping to l earn something. I was born without any electronic genes. I am building an a ll metal light sport plane.(Zenith) Right or wrong, I developed the habit ( over five decades of personal, military and commercial flying) of listening to broadcast radio on the ADF. I'm thinking that I need to install an of t he shelf automobile radio in my project. No second hand Ebay ADF's. My two questions are: Will I fry the radio if I use only a headset and no speakers ? About the antenna. I know that I should mount it vertically, but it must withstand airspeed excursions to Vne (156kts/180mph) without going L shaped . I've come up with somehow jamming it inside the canopy, or insulating it and mounting against the landing gear, or inside some kind of tubular mast on the belly. I did come across a NOS Volkswagen telescoping antenna in my shop. It would be great if that Lyc carburetor turns up again the same way. Somebody stop me if I'm on the wrong track. This isn't the most pressing p roblem out there, but all suggestions are appreciated.=0ABob Dingley =0A ________________________________ Message 10 ____________________________________ Time: 02:25:15 PM PST US From: "Richard Girard" Subject: Re: AeroElectric-List: Dumb questions Bob, I'm no expert, but I did learn this from one. Some automotive audio systems use completely separate grounds for each channel. For that you'd have to rewire your headphones and run three jacks instead of two. This info may be old, it was a few years ago and things move on, but it never hurts to ask the sales guy or look at the wiring layout of any system you're thinking of buying. Rick On Jan 27, 2008 2:49 PM, wrote: > I have been sitting in the back row on this list, hoping to learn > something. I was born without any electronic genes. I am building an all > metal light sport plane.(Zenith) Right or wrong, I developed the habit (over > five decades of personal, military and commercial flying) of listening to > broadcast radio on the ADF. I'm thinking that I need to install an of the > shelf automobile radio in my project. No second hand Ebay ADF's. My two > questions are: Will I fry the radio if I use only a headset and no speakers? > About the antenna. I know that I should mount it vertically, but it must > withstand airspeed excursions to Vne (156kts/180mph) without going L shaped. > I've come up with somehow jamming it inside the canopy, or insulating it and > mounting against the landing gear, or inside some kind of tubular mast on > the belly. I did come across a NOS Volkswagen telescoping antenna in my > shop. It would be great if that Lyc carburetor turns up again the same way. > Somebody stop me if I'm on the wrong track. This isn't the most pressing > problem out there, but all suggestions are appreciated. > Bob Dingley > > > ************** > Start the year off right. Easy ways to stay in shape. > http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 > > * > > * > > ________________________________ Message 11 ____________________________________ Time: 02:56:55 PM PST US Subject: AeroElectric-List: Re: LEDs at 24volts? From: "rampil" LED Resistor exist to limit the current flow through the LED. You did not mention want kind of 24v supply you used to test your 12v LED with, I wonder if it had high internal resistance. Your safest bet is to add a serial resistor, otherwise the lifetime of the LED may be VERY short Ira -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=160713#160713 ________________________________ Message 12 ____________________________________ Time: 03:01:16 PM PST US From: Jeff Page Subject: AeroElectric-List: Z13-8 N error ? Reading through the docs on E-Mag and P-Mag products, I think the wiring as shown on Z13-8 version N is incorrect. First, the labels are switched. The P-Mag is the one with the internal power generator. Second, the wiring for the real P-Mag I believe is incorrect. As shown, in the center test position, the P-lead, pin 4 is grounded and the battery bus is applied to pin 5. The engine should stop if the P-lead is grounded and it is not possible to test the internal power generator if there is power externally applied. Keep the wiring all the same, but specify the switch as S700-2-1 and I think it should be correct. Jeff Page Dream Aircraft Tundra #10 ________________________________ Message 13 ____________________________________ Time: 06:22:58 PM PST US From: Ralph Hoover Subject: AeroElectric-List: LEDs at 24volts? If you know or measure the current of the LED at 12 V you can divide 12 by the current and obtain the correct series resistor to maintain the same current at 24. Assuming about 20ma for a run of the mill led you would get 600 ohms. 12V across 600 ohms will dissipate .24W so a 1/2 watt resistor would be in order. You will probably find that if the LED doesn't fail at 24V it's series resistor may!! You will find either 560 or 620 ohm resistors are common values and either would work. -- Ralph C. Hoover RV7A hooverra at verizon dot net ________________________________ Message 14 ____________________________________ Time: 07:38:03 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z13-8 N error ? At 05:56 PM 1/27/2008 -0500, you wrote: > >Reading through the docs on E-Mag and P-Mag products, I think the >wiring as shown on Z13-8 version N is incorrect. > >First, the labels are switched. The P-Mag is the one with the >internal power generator. > >Second, the wiring for the real P-Mag I believe is incorrect. >As shown, in the center test position, the P-lead, pin 4 is grounded >and the battery bus is applied to pin 5. The engine should stop if >the P-lead is grounded and it is not possible to test the internal >power generator if there is power externally applied. >Keep the wiring all the same, but specify the switch as S700-2-1 and I >think it should be correct. I checked the drawings again and they are correct as published. The P-Mag is wired to the main bus. This lets you do the occasional "test" of the internal alternator by shutting down the main bus while the engine is running. This is easy to do by configuring the system to the ENDURANCE MODE where flight is sustained with only the E-bus and battery-bus hot. Emagair suggests this test be conducted infrequently . . . about as often as you would test the ENDURANCE MODE of operation for your electrical system. Emagair's drawings do not exploit this feature unique to Z-13/8 . . . and it should not. The vast majority of their customers will not be using Z-13/8. I hope that the majority of my customers ARE using Z-13/8. The E-mag is wired to run from the always-hot battery bus. A means by which power can be removed from the ignition system at shutdown is necessary. Hence the double-pole, three- position, progressive transfer switch offers independent control of E-Mag power and ONLY AFTER the E-mag has been shut down by means of grounding pin 4 (control) has been suggested. This particular architecture was crafted to support AeroElectric Connection philosophy for having all electrically dependent engine functions run from a battery bus. This goes toward a design goal that allows shutting down the entire electrical system with minimal (if not zero) influence on engine operations. Since the E-Mag needs power, it has been wired to the battery bus. The P-Mag is internally powered and needs only occasional tests of its internal power operations . . . which is easy to do when wired as shown by combing the ignition tests with any ENDURANCE MODE tests one might choose to conduct on the rest of the system. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 15 ____________________________________ Time: 08:08:24 PM PST US From: "Greg Young" Subject: RE: AeroElectric-List: Circuit breaker polarity > > In any case, it's not uncommon for a manufacturer > to use common tooling to mold a breaker housing > for all versions, hence you often see the word > "load", "line" or both formed right next to the > breaker's terminals . . . That's likely. There are a bunch of P-B series that use the same case. > > I've asked several tech reps for breakers and > except for enhanced breakers, orientation in > the system doesn't matter. Interestingly enough, > if an electrician encounters "line" and/or "load" > labels on a breaker, he'll wire it up that way > whether it matters or not. And I suspect many > aviation techs do too . . . not because the > physics matters but because some inspector who > doesn't know any better can be counted on to > insist that the protocols be followed. It just happened that the labeling on the P-B's matched my preferred bus bar mounting. The Klixon row below it has the bar on the opposite terminals which then looked wrong to the "do it the standard way and don't ask why" crowd. > The only time I've encountered this as a > "problem" is when a builder finds it convenient > to fabricate a two-row bus-bar and take load > feeders off opposite ends of the breaker. When > they come stamped with a breaker rating, > they look pretty funky with one row upside-down > in their holes! > > Bob . . . > Thanks for reaffirming my choices. Insightful as always. Regards, Greg Young ________________________________ Message 16 ____________________________________ Time: 08:10:00 PM PST US From: "Jeffrey W. Skiba" Subject: AeroElectric-List: TNC connections Okay, I am having a hard time finding the comic book or other type simple guide to making TNC connections. Is there such a creature at aeroelectic? I found the one for bnc http://www.aeroelectric.com/articles/bnccrimp.pdf is the tnc similar? I ask since my Garmin 430 was converted to the new Garmin 430W and that GPS antenna has a tnc connector. Thanks in advance. Jeff. ________________________________ Message 17 ____________________________________ Time: 10:09:55 PM PST US From: Jeff Page Subject: AeroElectric-List: Z13-8 N P-Mags You might think wiring up an electronic mag might be simple :-( Replacing the S700-2-10 with a S700-2-1 as I indicated in my previous post isn't the correct solution. It does allow removing external power to test the internal alternator, but in normal use, it removes external power before grounding the P-Lead, which is clearly stated by E-Mag as not the way to shut down the engine :-( At one point I had the design such that I used only three switches to control power/ground to the mags, allowing testing and with a position to engage the starter. However, it used three expensive switches and I have encountered poorer reliability with spring return types. The main problem really, is that the power to both mags was routed through one single switch. Since it is not being moved in flight, it is unlikely to fail, but .. My current plan is to use four of the simplest single-pole on-off switches, two for power and two for p-lead grounding, plus a push button for start. So that is a total of five switches, but much simpler and cheaper components and the plane will still fly if any one of them fails. I like the simple flow of operating the switches. However, I am not completely comfortable without a keyswitch, which would be difficult to include in this design. I do not like keyswitches, but there is a clear delineation between someone being (or not) permitted to start the aircraft if they are in possession of the key. To prevent starting, the key would need to disconnect mag power to avoid hand propping. The secret switch under the dash, used for auto anti-theft is a safety of flight issue. Anyone have any good ideas how to handle this ? Jeff Page Dream Aircraft Tundra #10 ------------------------------------------------------------------------------------- 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.