---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 04/09/06: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:36 AM - Re: Air Speed Switch (ivorphillips) 2. 04:02 AM - Re: Air Speed Switch (ivorphillips) 3. 04:06 AM - Panel grounding (Benjamin =?iso-8859-1?Q?Fr=E9mond?=) 4. 04:29 AM - Re: Air Speed Switch (Werner Schneider) 5. 05:46 AM - Re: Air Speed Switch (Ken) 6. 08:05 AM - Re: Air Speed Switch (Richard Riley) 7. 09:46 AM - Air Speed Switch (BobsV35B@aol.com) 8. 10:02 AM - Re: Why use starter contactor? () 9. 10:47 AM - Re: Air Speed Switch (Bill Denton) 10. 12:55 PM - Re: Air Speed Switch (Larry Ford) 11. 01:11 PM - Re: Panel grounding (Robert L. Nuckolls, III) 12. 01:35 PM - Re: Air Speed Switch (Jan de Jong) 13. 01:39 PM - Re: Air Speed Switch (Brian Lloyd) 14. 08:16 PM - Molex Pins (Jerry2DT@aol.com) 15. 09:53 PM - Overvoltage, faulty switch (Vern Little) ________________________________ Message 1 _____________________________________ Time: 02:36:08 AM PST US From: "ivorphillips" Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: "ivorphillips" Try http://rswww.com/cgi-bin/bv/rswww/subRangeAction.do?cacheID=ukie It works well as a stall warner, If you reverse the Inlet pipe it will work as a pressure switch, And its ajustable! Ivor phillips ________________________________ Message 2 _____________________________________ Time: 04:02:56 AM PST US From: "ivorphillips" Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: "ivorphillips" http://rswww.com/cgi-bin/bv/initSession.jsp?goto=/rswww/subRangeAction.do&catoid=-1600769365&store=uk > > It works well as a stall warner, If you reverse the Inlet pipe it will > work as a pressure switch, And its ajustable! The previous link didnt seem to work, But this one should! Ivor Phillips ________________________________ Message 3 _____________________________________ Time: 04:06:28 AM PST US From: Benjamin =?iso-8859-1?Q?Fr=E9mond?= Subject: AeroElectric-List: Panel grounding --> AeroElectric-List message posted by: Benjamin =?iso-8859-1?Q?Fr=E9mond?= Hi all, I build a Dyn'Aero MCR Sportster kit : this is a two seats carbon epoxy aircraft inspired from Michel Colomban's Bambi. It is Rotax 912 powered, and Z-16 wired. First flight expected in a few weeks ! Two years ago, before reading "The AeroElectric Connection" and subscribing to this list, I would never have thought of wiring it myself. And this is done ! And for the moment, in my garage, everything works well ! Many, many thanks to Bob Nuckolls and all the contributors of the list ! In this aircraft, the aluminium panel is electrically isolated from the airframe, due to the rubber shock-mounts and the composite structure. I don't know whether the cases of my VHF (Microair M760), transponder (Filser TRT600) and intercom (Flightcom 403 mc) are all internally grounded or not (to the avionics ground bus, via their respective D-sub connectors and harnesses) but if only one does, the panel itself is actually grounded too, via its case, and possibly tiny internal connections. Is it then mandatory (or facultative) to add a big wire between the panel and the forest-of-ground-tabs ? My concerns are, in this order, security, protection of expensive avionics and noise. Any advice appreciated. Thanks, Benjamin Fremond Rennes, France ________________________________ Message 4 _____________________________________ Time: 04:29:09 AM PST US From: Werner Schneider Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: Werner Schneider DonVS wrote: >--> AeroElectric-List message posted by: "DonVS" > >Bob, >The switch is recomended by Avidyne for use with their TCAS systems. It is >to take the device out of ground mode and into airborne mode. I used to fly >a piper twin that had the same type of switch to start the "air hobbs" >meter. BTW Avidyne does not have a source, that is why I am hoping that you >had one. Thanks. Don > >-----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, April 08, 2006 3:52 PM >To: aeroelectric-list@matronics.com >Subject: Re: AeroElectric-List: Air Speed Switch > > Don, I'm using an air switch from conrad electronics, and it does close (adjusted) with 45 kts (part #185990), however they have a smaller one too, check that and below you have a list with even smaller one (part # 185981). It seems they are from Micro Pneumatic Logic and run under product spec MPL-503 Hope it helps Werner ________________________________ Message 5 _____________________________________ Time: 05:46:36 AM PST US From: Ken Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: Ken Wouldn't a switch on the landing gear be easier and more reliable? Ken Dave Morris \"BigD\" wrote: >--> AeroElectric-List message posted by: "Dave Morris \"BigD\"" > >Why don't you just buy a cheap microswitch and keep sticking larger >and larger surface area on it until it triggers at the desired speed >while it's being hung out the window of your car? > > ________________________________ Message 6 _____________________________________ Time: 08:05:05 AM PST US From: Richard Riley Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: Richard Riley At 05:38 AM 4/9/2006, you wrote: >--> AeroElectric-List message posted by: Ken > >Wouldn't a switch on the landing gear be easier and more reliable? >Ken Depending on the geometry of the landing gear it may not be possible, unless you're talking about dragging a feeler on the ground. And in that case, no, I think an airspeed switch would be simpler and more reliable. ________________________________ Message 7 _____________________________________ Time: 09:46:35 AM PST US From: BobsV35B@aol.com Subject: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 4/9/2006 1:18:29 A.M. Central Standard Time, BigD@DaveMorris.com writes: Why don't you just buy a cheap micro switch and keep sticking larger and larger surface area on it until it triggers at the desired speed while it's being hung out the window of your car? Dave Morris Good Morning Dave, That should work, but if you are going to rely on a plate that is out in the breeze, it will add drag to the aircraft. If you place a switch in the pitot system that reacts to the pressure, there will be no additional drag added to the flying machine. Do Not Archive Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Air Park LL22 Downers Grove, IL 60516 630 985-8503 ________________________________ Message 8 _____________________________________ Time: 10:02:33 AM PST US From: Subject: AeroElectric-List: Re: Why use starter contactor? --> AeroElectric-List message posted by: >From: "Robert L. Nuckolls, III" >I was at OSH one year when a story flashed around the field >about one of the airshow performers having landed and discovering >that his starter and ring gear were all chewed up. The off-hand >diagnosis was that high g-loading during his performance caused >a tentative closure and subsequent welding of his starter >contactor. I would have given $100 to get my hands on all the >parts and to see how they were installed. >I would guess that it's far more likely that the starter >stuck on initial cranking of the engine and the pilot >was mentally concentrating on the performance task before >him. He might have made good use of the $1 processor. Bob: >I would guess that it's far more likely that the starter >stuck on initial cranking of the engine and the pilot >was mentally concentrating on the performance task before >him. He might have made good use of the $1 processor. Don't you there's a good chance the firewall solenoid was mounted in a manner that positive G's caused it to close. This is common on acro planes with firewall contactors mounted where pos G's close them. Van's aircraft found this and than recommended the contactor be mounted sideways. Well that also turned out to be a bad idea. Because the solenoid Van's sells is not made for sideways mounting, the solenoid galled and failed. The ultimate solution was to mount the start solenoid so Positive G's would keep the contacts open, since negative G's are less critical, the way to mount was with the metal cap down (on typical contactor). http://www.vansaircraft.com/cgi-bin/catalog.cgi?ident=1144596827-336-39&browse=electrical&product=start-sw (as shown) Here is some more goodies from SkyTec's site: As far as unknown run-on? starter backdriving. Why not install a run-on light if possible (think it applies to HT model): http://www.skytecair.com/images/warning%20lights%202.JPG http://www.skytecair.com/images/Starter_RunOn_Doc.pdf (also see note below on Robinson HT skytec starter) How to wire a starter push button: http://www.skytecair.com/images/ST2_Wiring.pdf Interesting SkyTec standard or replacing B&C on Robinson Helicopters? http://www.skytecair.com/images/HT%20Robinson%20Convert.pdf Also the new SkyTec NL starter NEEDS a firewall solenoid: http://www.skytecair.com/Wiring_diag.htm (No choice, you must use a FW solenoid with the new NL starter) New NL starter, cool animation on reset of shear pin http://www.skytecair.com/NL%20Shear%20Pin.htm http://www.skytecair.com/Lycoming.htm Interesting note on shower of sparks and helicopter wiring: http://www.skytecair.com/Helicopter_wiring.htm (some one commented on a problem, I think this is relative) George --------------------------------- ________________________________ Message 9 _____________________________________ Time: 10:47:57 AM PST US Subject: AeroElectric-List: Re: Air Speed Switch From: "Bill Denton" --> AeroElectric-List message posted by: "Bill Denton" You might take a look at this one: http://www.alliedelec.com/Search/ProductDetail.asp?SKU=634-0005&SEARCH=6753%2DAEJA%2DA000&ID=&MPN=6753%2DAEJA%2DA000&DESC=6753%2DAEJA%2DA000 I believe this is the one that Microair uses with their transponders to switch them out of standby when the aircraft reaches a specific speed. Good luck! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=27151#27151 ________________________________ Message 10 ____________________________________ Time: 12:55:01 PM PST US From: "Larry Ford" Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: "Larry Ford" Take a look at the World Magnetics line available thru Digikey at www.designflexswitches.com . There's a new Goldtech line that looks promising for the application. This also looks favorable for a pitot based "squat" switch or a gear warning sensor based on airspeed. The previously available switches were either normally open (PSF102), weren't sensitive below 2" H20 (PSF 103). This new switch appears to be able to handle switching loads for the landing gear solenoid in the application where you would prevent gear retraction for airspeeds below 70 knots (3.159" H20) with the switch in series. I've been waiting for something like this! What do you gurus think? Larry Ford Glasair I RG N149LF ________________________________ Message 11 ____________________________________ Time: 01:11:34 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Panel grounding --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:09 PM 4/9/2006 +0200, you wrote: >--> AeroElectric-List message posted by: Benjamin >=?iso-8859-1?Q?Fr=E9mond?= > >Hi all, > >I build a Dyn'Aero MCR Sportster kit : this is a two seats carbon epoxy >aircraft inspired from Michel Colomban's Bambi. It is Rotax 912 powered, >and Z-16 wired. First flight expected in a few weeks ! Two years ago, >before reading "The AeroElectric Connection" and subscribing to this list, >I would never have thought of wiring it myself. And this is done ! And for >the moment, in my garage, everything works well ! Many, many thanks to Bob >Nuckolls and all the contributors of the list ! > > >In this aircraft, the aluminium panel is electrically isolated from the >airframe, due to the rubber shock-mounts and the composite structure. > >I don't know whether the cases of my VHF (Microair M760), transponder >(Filser TRT600) and intercom (Flightcom 403 mc) are all internally grounded >or not (to the avionics ground bus, via their respective D-sub connectors >and harnesses) but if only one does, the panel itself is actually grounded >too, via its case, and possibly tiny internal connections. > >Is it then mandatory (or facultative) to add a big wire between the panel >and the forest-of-ground-tabs ? My concerns are, in this order, security, >protection of expensive avionics and noise. If you never grounded it, as long as all other grounds get back to the single point firewall ground, you're not likely to perceive any problems with respect to noise or other functionality. However, as a matter of practice in big airplanes, we BOND large hunks of 'floating' metal to heavier ground structures, mostly for lightning stroke issues. It's a toss up. Of course one never expects to get hit by the big one but when and if it does happen - See: http://aeroelectric.com/articles/Anatomy_of_a_Lightning_Strike.pdf Then likelihood of your electronics surviving (or at least mitigating damage) goes up if you put a hefty ground conductor from panel to firewal. I'd suggest a 10AWG with its own bolt on the panel and a ring terminal on the other end to take it to the 5/16 brass firewall passthru bolt. The fact that all other grounds go to this same point means that you'll have no ground-loop generated noises in spite of the fact that multiple systems share common grounds at both ends (panel and firewall). Bob . . . ________________________________ Message 12 ____________________________________ Time: 01:35:17 PM PST US From: Jan de Jong Subject: RE: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: Jan de Jong World Magnetics would seem to make a useful switch? See http://dkc3.digikey.com/PDF/T061/1703.pdf Cheers, Jan de Jong ________________________________ Message 13 ____________________________________ Time: 01:39:19 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Air Speed Switch --> AeroElectric-List message posted by: Brian Lloyd Larry Ford wrote: > --> AeroElectric-List message posted by: "Larry Ford" > > This also looks favorable for a pitot based "squat" switch or a gear warning sensor based on airspeed. > ... > What do you gurus think? Larry Ford Glasair I RG N149LF I think that I have been annoyed with every kind of landing gear warning system I have ever used. Piper had their automatic system that put the gear down when you slowed down and that just about drove everyone nuts. The only system I have really liked is to do my GUMP check twice: once on downwind to get all the stuff done and again on final to make sure I didn't forget anything. If on instruments putting the gear down at the FAF usually sets my descent rate to the runway. I know, it's not high tech. OTOH it is KISS. -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 14 ____________________________________ Time: 08:16:13 PM PST US From: Jerry2DT@aol.com Subject: AeroElectric-List: Molex Pins --> AeroElectric-List message posted by: Jerry2DT@aol.com List, Some of my avionics have molex connectors and I know Bob is an advocate of wire support just outside or as part of the crimp. The molex pins for the 20-22 awg wiring seem awfully fragile. the crimps comprise two parts, which I assume are to grip the wire and then the insulation. However, these appear flimsy and would seem prone to vibration damage. Unlike D-Subs, they do not have a cover with secondary support. Am I worrying about nothing or is there something else I'm missing ? Any advice always a plus, and thanks... Jerry Cochran RV6a.. Close... ________________________________ Message 15 ____________________________________ Time: 09:53:52 PM PST US From: Vern Little Subject: AeroElectric-List: Overvoltage, faulty switch --> AeroElectric-List message posted by: Vern Little Since my first flight of my RV-9A in January, I've been plagued with over-voltage alarms. I've been through the alternator field circuit several times, re-seating fast-on terminals. This always seemed to fix the problem for several operating hours. On Friday, I was flying over the mountains when I had an alarm again, so I shut the alternator off and began an in-flight diagnostic. On the ground, my inspection revealed that I have a bad S700-2-10 switch (my Master Switch). All of the fast-on terminals are riveted in place on this particular switch, and the rivets were quite loose, making the connections intermittent and resistive. My short term fix in flight was to wiggle the terminals by reaching under the panel with my fingers. I've contacted B&C for a replacement, and I've offered to send the bad one back to them for analysis. Has anyone else seen this problem? Vern Little