---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 07/14/07: 18 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:36 AM - Re: Connecting a Garmin (Apollo) SL40 COM to a PS Engineering PMA4000 Audio Panel (Steve Glasgow) 2. 05:13 AM - CDI Switch? () 3. 06:03 AM - Re: best contactor reliability -- mechanical, solid state, or manual? (Robert L. Nuckolls, III) 4. 06:23 AM - Re: Connecting a Garmin (Apollo) SL40 COM to a PS Engineering PMA4000 Audio Panel (Ron Quillin) 5. 06:41 AM - Re: Plane-Power (Robert L. Nuckolls, III) 6. 06:43 AM - Where to start (Alan K. Adamson) 7. 07:23 AM - Re: CDI Switch? (Eric M. Jones) 8. 08:10 AM - Re: best contactor reliability -- mechanical, solid state, or ma (Eric M. Jones) 9. 08:45 AM - Re: Where to start (Robert L. Nuckolls, III) 10. 09:26 AM - Re: Where to start (Robert L. Nuckolls, III) 11. 09:49 AM - Semi-Custom Products (Robert L. Nuckolls, III) 12. 12:00 PM - Re: Where to start (Alan Adamson) 13. 02:13 PM - Re: Garmin 430 transmitter problem (David Abrahamson) 14. 02:30 PM - Re: S700 2-50 Switch / Electric Fuel Pump (Frank Stringham) 15. 05:37 PM - Re: Re: S700 2-50 Switch / Electric Fuel Pump (Frank Stringham) 16. 06:29 PM - Switch guards, switch locks, locking switches? (Christopher Barber) 17. 06:29 PM - Switch guards, switch locks, locking switches? (Christopher Barber) 18. 07:34 PM - Re: Switch guards, switch locks, locking switches? (John McMahon) ________________________________ Message 1 _____________________________________ Time: 03:36:14 AM PST US From: "Steve Glasgow" Subject: Re: AeroElectric-List: Connecting a Garmin (Apollo) SL40 COM to a PS Engineering PMA4000 Audio Panel I'm just about to go through the same thing only with an SL30. If you call Tony at Stark Avionics I'm sure he will have the correct answer. He has been very helpful in my other endeavors so far. Steve Glasgow-Cappy N123SG RV-8 Cappy's Toy 704-362-0005 Home 704-281-7884 Cell ________________________________ Message 2 _____________________________________ Time: 05:13:36 AM PST US From: Subject: AeroElectric-List: CDI Switch? 7/14/2007 Hello Eric, Great equipment choice. Switching can be done with a mulltiple pole remote relay controlled by a push button switch that shows which mode you are in. Ameri-King has some relays: http://www.ameri-king.com/ So does Northern Airborne Technology, but their web site is pretty opaque. 'OC' Says: "The best investment we can make is the effort to gather and understand knowledge." Time: 02:32:38 PM PST US From: "Eric Parlow" Subject: AeroElectric-List: CDI Switch? What's the best way to switch the CDI input from GPS-WAAS to Nav1 to Nav2? I have the Garmin GI106A, GNS430W, SL30 combination. The GNS430W allows you to switch between GPS-WAAS and NAV1 internally. Also the GNS430W and the SL30 are feeding GPS/VOR/ILS to the Blue Mountian(BMA) EFIS/One. The GNS430W via an analog connection and SL30 via the serial link. The BMA autopilot is only able to be driven by the BMA EFIS/One. Sincerely, ERic-- RV-10, N104EP ________________________________ Message 3 _____________________________________ Time: 06:03:26 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: best contactor reliability -- mechanical, solid state, or manual? At 05:27 AM 7/13/2007 -0400, you wrote: > >On 13 Jul 2007, at 04:38, D Wysong wrote: > >> >>I have a remotely operated application where the loss of the master >>battery contactor will result in the loss of data/money/time (... >>and dignity!). My baseline design resembles a "Z" diagram (thanks >>Bob!) and I planned to use a mechanical, continuous duty contactor >>like the S-701 from B&C. However, a buddy of mine recently >>experienced a contactor failure in flight and it caused me to >>experience a few "What If!?" nightmares. I'm back to reconsidering >>my original decision... Help us with a bit more information about your application. What kind of vehicle? What kind of environment? What's the energy requirement to maintain data in vulnerable systems. It's often much easier to arrange for brownout and/or momentary power loss for a few items than to back-up the whole system. Finally, it's almost always better to have a plan-a/plan-b modus operandi than to scratch around for "more reliable" hardware. EVERYTHING will break at some point in time. Give us a rundown of your equipment that must stay awake and what the power requirements are. Bob . . . ________________________________ Message 4 _____________________________________ Time: 06:23:42 AM PST US Subject: Re: AeroElectric-List: Connecting a Garmin (Apollo) SL40 COM to a PS Engineering PMA4000 Audio Panel From: Ron Quillin At 20:28 7/13/2007, you wrote: >What I'd like is for some to confirm that they match up (are >connected ) as follows: > >Headphone - 14 to Com 1 Audio HI - Top -19 >Audio Ground - 13 to Com 1 Audio LO - Top - 7 >Mic 1 - 8 to Com Mic Audio HI - Bottom - 21 >Mic Ground - 7 to Com 1 Audio LO - Bottom 9 >TxKey - 4 to Com 1 PTT - Bottom - 22 > >Thanks for suffering thought these details with me. It seems that >PS Engineering refers to the ground as "LO" consistently. > >Jeff Davidson Should work fine Jeff, as you've indicated. -Back in the days-, before all our new solid state electronics, many audio systems were truly 'balanced'; that is for increased noise rejections capability neither signal was ground referenced, but referenced to one another. A ground referenced shield covered the pair. Low signal level signals, microphone lines for example, are still, in professional systems, done this way. However, the higher level 'line' level signals, that used to be 500 or 600 ohm balanced lines, have for the most part become single-ended; with a high signal and a ground return completing the path. You will note most of our com radios have a ~500 ohm output and most intercoms and audio panels have their input impedance spec'd as ~500 ohms despite the fact generally in newer equipment neither really is. It's a carry over for compatibility with as MS would name, legacy equipment. But still a good idea when properly implemented and interconnected. Problem here with 'single ended (not balanced) systems' is that the signal will "see" any stray currents and voltage drops through the resistance of the real world as an additional voltage. That additional voltage will appear as unwanted noise, or whatever, with the signal we desire; an especially bothersome issue with the low level signals our microphones provide. With the higher level line signals it's less a problem, but is just ignored by many manufacturers. PS, to their credit, didn't ignore the real or old world and provisioned their equipment with both hi and low inputs for those wishing to use shielded twisted pair cable to reduce noise in all interconnects. While their "lo" may still be very similar to ground, it is still provided and by following their IM one can end up with an audio system having greater immunity to externally generated noise; this by running the 'lo' along with the 'hi' and not using the airframe as the signal return. It's very important to keep the microphone jack mounting bushing, and to a lessor degree the headphone as well, insulated from the airframe and rely on the LO wire to provide that connection. To not do so negates the advantage of what PS has provided us. Ron Q. ________________________________ Message 5 _____________________________________ Time: 06:41:48 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Plane-Power At 01:36 PM 7/12/2007 -0500, you wrote: > > > >Hi Bob, > >I was just curious if you had had any time to explore any of Plane-Power's >internally regulated alternators on that fancy alternator stand? > >Thanks, No. My duties with an ageing father in Medicine Lodge, putting down new hardwood floors on my house and needs of my new clients (out of town 4 days last week and 3 days next week) have push my drive-stand project back into the corner. Actually, I have no particular plans to test Plane-Power's products. They are wired exactly the same architecture and alternator control philosophy that you would get if if you did a B&C LR-3 installation on an externally regulated alternator . . . or figure Z-11 from the book. I intend to explore the energy questions on alternators in general with a goal of achieving positive on/off, any time, any conditions control of an internally regulated alternator that is NOT modified per the Plane Power manufacturing philosophy. I.e. off the shelf automotive. I can deduce no reason to be skeptical of Plane Power's product performance claims. Bob . . . ________________________________ Message 6 _____________________________________ Time: 06:43:18 AM PST US From: "Alan K. Adamson" Subject: AeroElectric-List: Where to start Ok, so I'm doing a little remote diagnostics. I've got a friend who has a dual battery, dual alternator system. It's flown for 75 hrs with no problems and now has developed an odd on. It uses 2 12v Odyssey batteries, and a regular Continental alternator and an SD-20 both regulated with B&C LR3's. Charging starts out fine and in about 15 mins, both alternators shut off and he's on battery only until he descends to a lower altitude (not predictable) or shuts down the electrical for some time and then brings both Alts back on line. We've tried the turn on a load, turn off a load routing, also he had been flying with his crosstie on all the time and this last flight he stared with crosstie on and then turned it off and it made no difference. Anyone care to offer the short version of where to start and what to look for besides the obvious, wire loose, connector broken, ground failed, etc? Thanks in advance, Alan ________________________________ Message 7 _____________________________________ Time: 07:23:44 AM PST US Subject: AeroElectric-List: Re: CDI Switch? From: "Eric M. Jones" I think Perihelion Design has a relay for the job. (Originally a B Nuckolls design). http://www.periheliondesign.com/18polerelays.htm Parts list and PCB design are free for the asking. Assembled unit is cheap. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=123775#123775 ________________________________ Message 8 _____________________________________ Time: 08:10:16 AM PST US Subject: AeroElectric-List: Re: best contactor reliability -- mechanical, solid state, or ma From: "Eric M. Jones" Some reuse from an email to a customer here...) Compare--- ____________________Type 70_____GX-11 Weight.........................12.5 Oz.............18 Oz Temp...........................50 DegC...........75-85 DegC (50 degC 122 F) makes the type 70 unusable.... Position........................Cap Down..........Any Environmental...............Dust-Proof.........Hermetically sealed Coil Suppression............Must be added....Built in B&C Type 70 uses diodes, GX-11 uses transorbs (SnapJacks!) Continuous Amps............80 at 50C..........150A at 75C Inrush A.........................150...................500-2000 Open against Vmax.......... 35V.................>>100V (...same as Kilovac) Hold current.....................1.0 A................700 mA (Kilovac is 100 mA, Gigavac has lower hold currents on request) G-force opening...............2G ??................>>10G Anyway the GX11 will be about $120, but the Type 70 ($37.00 from Newark) is not really useable in my opinion. You may want the accessory contacts and long leads...couldn't hurt. The Kilovac EV200aaana (aka Blue Sea 9014) is still great (similar to the Gigavac GX11). The type 70 is problematic even if very common and long in the tooth. It is deficient in three main areas: 1) Poor coil suppression (this can be retrofitted to improve it) 2) Inadequate operating temperature. My GUESS is that the early ones had fiber/bakelite interiors, now they are Nylon. Regardless 122F spec is way too low to use. 3) Inadequate G force withstand. 2G ?? 4) Open against Vmax. 35V. They caould sustain an arc if the alternator runs away. Pure solid state solutions are not quite ready. I have experimented with this, and continue to do so. There are some remarkable devices in development. Mechanical contactors--"Flaming River" seems to come up when people talk about quality. I would like some people to describe what happens to lower quality mechanical contactors, but I haven't heard details. "The despotism of custom is everywhere...the standing hindrance to human advancement." --John Stuart Mill -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=123780#123780 ________________________________ Message 9 _____________________________________ Time: 08:45:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Where to start At 09:42 AM 7/14/2007 -0400, you wrote: > > >Ok, so I'm doing a little remote diagnostics. I've got a friend who has a >dual battery, dual alternator system. It's flown for 75 hrs with no >problems and now has developed an odd on. > >It uses 2 12v Odyssey batteries, and a regular Continental alternator and an >SD-20 both regulated with B&C LR3's. > >Charging starts out fine and in about 15 mins, both alternators shut off and >he's on battery only until he descends to a lower altitude (not predictable) >or shuts down the electrical for some time and then brings both Alts back on >line. We've tried the turn on a load, turn off a load routing, also he had >been flying with his crosstie on all the time and this last flight he stared >with crosstie on and then turned it off and it made no difference. > >Anyone care to offer the short version of where to start and what to look >for besides the obvious, wire loose, connector broken, ground failed, etc? > >Thanks in advance, >Alan The airplane should be flown with the CROSS-TIE OPEN. This is the whole purpose of dual, independent systems is to eliminate the possibility of a failure affecting both systems. If leaving the cross tie open does not change the observed phenomenon, then I suspect a wiring error. The cross-tie contactor is, for some reason remaining closed. There has to be something else going on as well. The only thing I can think of that would have such a profound effect on both systems is a flaky ground connection between crankcase and firewall ground stud. Bob . . . ________________________________ Message 10 ____________________________________ Time: 09:26:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Where to start At 10:46 AM 7/14/2007 -0600, you wrote: > > >At 09:42 AM 7/14/2007 -0400, you wrote: > >> >> >>Ok, so I'm doing a little remote diagnostics. I've got a friend who has a >>dual battery, dual alternator system. It's flown for 75 hrs with no >>problems and now has developed an odd on. >> >>It uses 2 12v Odyssey batteries, and a regular Continental alternator and an >>SD-20 both regulated with B&C LR3's. >> >>Charging starts out fine and in about 15 mins, both alternators shut off and >>he's on battery only until he descends to a lower altitude (not predictable) >>or shuts down the electrical for some time and then brings both Alts back on >>line. We've tried the turn on a load, turn off a load routing, also he had >>been flying with his crosstie on all the time and this last flight he stared >>with crosstie on and then turned it off and it made no difference. >> >>Anyone care to offer the short version of where to start and what to look >>for besides the obvious, wire loose, connector broken, ground failed, etc? >> >>Thanks in advance, >>Alan > > The airplane should be flown with the CROSS-TIE OPEN. This is > the whole purpose of dual, independent systems is to eliminate > the possibility of a failure affecting both systems. If leaving > the cross tie open does not change the observed phenomenon, > then I suspect a wiring error. The cross-tie contactor is, for > some reason remaining closed. There has to be something else > going on as well. The only thing I can think of that would > have such a profound effect on both systems is a flaky ground > connection between crankcase and firewall ground stud. Got my keyboard cord tangled around my eyeteeth and couldn't see what I was typing. Ignore all the above about cross-tie operation. I can see that I'd mis-read the significance of the cross-tie switch in your dissertation of observed events. Check out that grounding thing. Bob . . . ---------------------------------------- ( "Physics is like sex: sure, it may ) ( give some practical results, but ) ( that's not why we do it." ) ( ) ( Richard P. Feynman ) ---------------------------------------- ________________________________ Message 11 ____________________________________ Time: 09:49:43 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Semi-Custom Products I've been working on a line of new products for the AeroElectric Connection website that will be unique to AEC. We're going to resist being a dealer for other folks products. One project utilizes an ECB and enclosure that has features described in these two illustrations: http://www.aeroelectric.com/DIY/A15_Package.jpg http://www.aeroelectric.com/DIY/Do-Much_Board_Schematic.pdf The schematic would never have ALL components installed, and in some cases, components left of are replaced with solid jumpers. However, depending on what parts are installed, their values, and what software is installed in the microcontroller, we can craft a variety of products with 98% commonality of bill of materials. The first product to be offered under this design and marketing philosophy is described at: http://www.aeroelectric.com/Catalog/AEC/9011/9011-700-1C.pdf . . . except that it will have a 15-pin connector on it instead of a 9-pin. I'm publishing the schematic for the more technically inclined. Perhaps the architecture will suggest an application close to your own wishes for a smart black box to do some task. If so, let's talk about it and see if my software guy can't whip it out in reasonably short order and save you a lot of development time to craft a nicely packaged electro-whizzy. Or, if you want to do your own byte-pudding I could offer you a kit of ECB and enclosure from which you could move your project ahead. Bob . . . ---------------------------------------- ( "Physics is like sex: sure, it may ) ( give some practical results, but ) ( that's not why we do it." ) ( ) ( Richard P. Feynman ) ---------------------------------------- ________________________________ Message 12 ____________________________________ Time: 12:00:33 PM PST US From: "Alan Adamson" Subject: RE: AeroElectric-List: Where to start Thanks Bob, and that is where we are going to start. Couple more tidbits... In talking with my friend. I found another strange oddity. He has enunciator lights that are connected to the LV warnings on the VR's, but they never went on. Also in talked with him, he said he has a "test" curcuit for his annunciators and only those 2 don't light. So, I think there is a couple of things we need to look at... The ground issues in general and the annunciation system. Something is allowing the alternators to start charging and then to drop off line at some point, but because the LV warnings don't flicker, he doesn't find out about the event until the engine monitor determines an LV condition and screams in his ear... At least we have some places to start.... If you think the LV curcuit being open might have a residual effect let us know that too... Thanks as always, Alan -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Saturday, July 14, 2007 1:26 PM Subject: Re: AeroElectric-List: Where to start --> At 10:46 AM 7/14/2007 -0600, you wrote: > > >At 09:42 AM 7/14/2007 -0400, you wrote: > >> >> >>Ok, so I'm doing a little remote diagnostics. I've got a friend who >>has a dual battery, dual alternator system. It's flown for 75 hrs >>with no problems and now has developed an odd on. >> >>It uses 2 12v Odyssey batteries, and a regular Continental alternator >>and an SD-20 both regulated with B&C LR3's. >> >>Charging starts out fine and in about 15 mins, both alternators shut >>off and he's on battery only until he descends to a lower altitude >>(not predictable) or shuts down the electrical for some time and then >>brings both Alts back on line. We've tried the turn on a load, turn >>off a load routing, also he had been flying with his crosstie on all >>the time and this last flight he stared with crosstie on and then turned it off and it made no difference. >> >>Anyone care to offer the short version of where to start and what to >>look for besides the obvious, wire loose, connector broken, ground failed, etc? >> >>Thanks in advance, >>Alan > > The airplane should be flown with the CROSS-TIE OPEN. This is > the whole purpose of dual, independent systems is to eliminate > the possibility of a failure affecting both systems. If leaving > the cross tie open does not change the observed phenomenon, > then I suspect a wiring error. The cross-tie contactor is, for > some reason remaining closed. There has to be something else > going on as well. The only thing I can think of that would > have such a profound effect on both systems is a flaky ground > connection between crankcase and firewall ground stud. Got my keyboard cord tangled around my eyeteeth and couldn't see what I was typing. Ignore all the above about cross-tie operation. I can see that I'd mis-read the significance of the cross-tie switch in your dissertation of observed events. Check out that grounding thing. Bob . . . ---------------------------------------- ( "Physics is like sex: sure, it may ) ( give some practical results, but ) ( that's not why we do it." ) ( ) ( Richard P. Feynman ) ---------------------------------------- ________________________________ Message 13 ____________________________________ Time: 02:13:29 PM PST US From: David Abrahamson Subject: Re: AeroElectric-List: Garmin 430 transmitter problem I received the following advice from a local avionics tech. "First thing I would look at is the Com1 circuit breaker. The 430 has two power circuits... one for the com and one for the nav/gps. The nav/gps will light the unit up and allow the Nav and GPS to work, but if the com side isn't getting any (or is getting low) voltage, then you would have transmission issues. So check the breaker to make sure it isn't giving a high resistance when closed, and that you have voltage going to the power pins on the com plug. It might just be best to replace the com breaker with a new one just to be sure. The next would be to swap com coaxes between the SL30 and the 430. If it follows the antenna, then you know it is the coax, antenna, or bonding issue. If it doesn't then you know you have an issue with the 430 transmitter." I haven't had a chance to go back out to the airport yet, but the very first thing I will check will be that I have a good ground to the 430's com circuit. Then, his suggestions. FWIW, one of Garmin's Aviation Field Service Engineers replied to my email with "This sounds like a problem in the GNS430 itself and will need to come back for repair." I'll advise what I find and do. David ________________________________ Message 14 ____________________________________ Time: 02:30:22 PM PST US From: "Frank Stringham" Subject: AeroElectric-List: RE: S700 2-50 Switch / Electric Fuel Pump Finishing up the switch wiring on my RV7A Panel. I am using Z13/8 to wire the aircraft. I am using the S700 2-50 switch to activiate my electric fuel pump. The momentary switch up side primes the engine and the full on down would be used incase of the primary fuel pump failure. The engine id fuel injected. Now the question. I am not quite sure how to wire this switch up to make all of this happen..... Frank @ SGU RV7A Panel/Wiring just about ready to hang the engine....when he gets here!!! _________________________________________________________________ http://liveearth.msn.com ________________________________ Message 15 ____________________________________ Time: 05:37:45 PM PST US From: "Frank Stringham" Subject: RE: AeroElectric-List: RE: S700 2-50 Switch / Electric Fuel Pump Answer found............Page 11-2 AeroElectric connections. Once again thanks Bob...... Now back to tryinjg to find other obvious things known to most that i can ask questions about Frank @ SGU RV7A Panel/Electrical >From: "Frank Stringham" >To: aeroelectric-list@matronics.com >Subject: AeroElectric-List: RE: S700 2-50 Switch / Electric Fuel Pump >Date: Sat, 14 Jul 2007 15:28:52 -0600 > > > >Finishing up the switch wiring on my RV7A Panel. I am using Z13/8 to wire >the aircraft. I am using the S700 2-50 switch to activiate my electric fuel >pump. The momentary switch up side primes the engine and the full on down >would be used incase of the primary fuel pump failure. The engine id fuel >injected. Now the question. I am not quite sure how to wire this switch up >to make all of this happen..... > >Frank @ SGU RV7A Panel/Wiring just about ready to hang the >engine....when he gets here!!! > >_________________________________________________________________ >http://liveearth.msn.com > > _________________________________________________________________ Need a brain boost? Recharge with a stimulating game. Play now! http://club.live.com/home.aspx?icid=club_hotmailtextlink1 ________________________________ Message 16 ____________________________________ Time: 06:29:07 PM PST US From: "Christopher Barber" Subject: AeroElectric-List: Switch guards, switch locks, locking switches? My project is an all electric bird (Velocity SE) with a rotary engine. Since if I loose power things get quite I am using Bob's duel alternator/duel battery set up. What I am curious about is the switches in the cabin. Currently I have all the switches up high on the panel a bit right of center towards the co-pilot position. I hope to not have a passanger who would inadvertanlty flip a switch down and off, HOWEVER, you never know what may get tangled or a stray move may flip a switch....in my set up, if my coil switch or primary injectors get switched off I will start sweating. Also, I don't really mind the switches where they are, but I do have a couple of other places I would like them, but I placed them here as to minimize being bumped. My question is what other options do I have to either guard against accidental deactivation. I have purchased a couple of aviation locking toggles from ebay, but they are kinda small and may not be up for the task (but at $13.00 I couldn't go too wrong...they may work for my coil switch and primary fuel). The regulare priced DPDT (for my contactors and injectors) seem to start at close to $60.00 a piece...a bit much for my police salery if other options will surfice. I have also considered those installing some of the switch guards you see in old nuclear missle bunker movies that they would open to expose the firing buttons for the big ol' missles. I considered installing them upside down (which is really easy) so that they are on when the cover is closed thus making the switch impossible to turn off by mistake. This seems really fool proof, however, the guards, while cheap, are pretty big and do not look all that, well, elligant. Also, I was watching the Astronaut Farmer last night on PPV and saw the little hard wire loops that where installed next to the switches on each side of the individual switches in his space capsule and this reminded me of the ones NASA used to use....maybe still do. Donno. These seem to be just half circles that make grabbing the switch very deliberate and minimizes potential knocks. Finally, it seems as if I have seen bars held in by springs that lay across a series of switches to keep them in place. What say ye? Insight? Wisdom? Warnings? Observations? WAG's? Thanks. All the best, Chris Barber Houston ________________________________ Message 17 ____________________________________ Time: 06:29:07 PM PST US From: "Christopher Barber" Subject: AeroElectric-List: Switch guards, switch locks, locking switches? My project is an all electric bird (Velocity SE) with a rotary engine. Since if I loose power things get quite I am using Bob's duel alternator/duel battery set up. What I am curious about is the switches in the cabin. Currently I have all the switches up high on the panel a bit right of center towards the co-pilot position. I hope to not have a passanger who would inadvertanlty flip a switch down and off, HOWEVER, you never know what may get tangled or a stray move may flip a switch....in my set up, if my coil switch or primary injectors get switched off I will start sweating. Also, I don't really mind the switches where they are, but I do have a couple of other places I would like them, but I placed them here as to minimize being bumped. My question is what other options do I have to either guard against accidental deactivation. I have purchased a couple of aviation locking toggles from ebay, but they are kinda small and may not be up for the task (but at $13.00 I couldn't go too wrong...they may work for my coil switch and primary fuel). The regulare priced DPDT (for my contactors and injectors) seem to start at close to $60.00 a piece...a bit much for my police salery if other options will surfice. I have also considered those installing some of the switch guards you see in old nuclear missle bunker movies that they would open to expose the firing buttons for the big ol' missles. I considered installing them upside down (which is really easy) so that they are on when the cover is closed thus making the switch impossible to turn off by mistake. This seems really fool proof, however, the guards, while cheap, are pretty big and do not look all that, well, elligant. Also, I was watching the Astronaut Farmer last night on PPV and saw the little hard wire loops that where installed next to the switches on each side of the individual switches in his space capsule and this reminded me of the ones NASA used to use....maybe still do. Donno. These seem to be just half circles that make grabbing the switch very deliberate and minimizes potential knocks. Finally, it seems as if I have seen bars held in by springs that lay across a series of switches to keep them in place. What say ye? Insight? Wisdom? Warnings? Observations? WAG's? Thanks. All the best, Chris Barber Houston ________________________________ Message 18 ____________________________________ Time: 07:34:53 PM PST US From: "John McMahon" Subject: Re: AeroElectric-List: Switch guards, switch locks, locking switches? You might look at www.PerihelionDesign.com for switch guards...... -- John McMahon Lancair Super ES, S/N 170, N9637M (Reserved) ------------------------------------------------------------------------------------- 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.