---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 02/07/04: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:22 AM - alternator switch (klehman@albedo.net) 2. 08:49 AM - Re: Re: OV protection for internally regulated (Jerzy Krasinski) 3. 09:31 AM - Re: Shielded wire options (John Schroeder) 4. 02:21 PM - Wing wiring (Terry Teer) ________________________________ Message 1 _____________________________________ Time: 07:22:23 AM PST US From: klehman@albedo.net Subject: AeroElectric-List: alternator switch --> AeroElectric-List message posted by: klehman@albedo.net I still have trouble with the need for absolute alternator control or a need for an alternator switch. I am referring to an internal vr alternator. If ov protection trips then I don't want to reset it in flight unless I suspect a nuisance trip. However nuisance ov tripping is unacceptable so I would want to correct that or remove the ov protection. If diodes short then the ANL is going to blow before I can manually turn off the alternator. If I think that I might have time and opportunity to turn it off before an impending crash then I'm pretty sure that I'll already have the engine shutoff and I don't expect my psru equipped engine to windmill so the alternator will already be dead. At this point I'm leaning toward a manual battery switch that is not on the panel so it can't be accidently turned off and no alternator switch. I'm still thinking about it but such an architecture would also allow me to run the electrically dependant engine loads through the manual batt switch. But heh I'm still listening ;) ... Another option that I'd like is for a reasonable cost replacement for the heavy (weight and current) contactor that seems to be required to add ov protection to my 40 amp alternator. With high current silicon these days, I'd almost think that there would be a way of directly crowbar shorting/blowing the B lead ANL. Hmmm now that I think about it there might even be some 100+ amp scr's in my junk box... I think they came from an AC/DC welder. Fortunately a lighter S704-1 relay seems to be acceptable for my 20 amp second alternator. Ken Yup, Figure Z-24 in the back of the AeroElectric Connection suggests a means for providing (1) absolute control of an internally regulated alternator and (2) providing ov protection. ________________________________ Message 2 _____________________________________ Time: 08:49:25 AM PST US From: Jerzy Krasinski alternators Subject: Re: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: Jerzy Krasinski alternators Jack Bloodgood wrote: > > >Hello, > >Just a thought that where appropriate we might profit from the marine >industry. Almost all private boats have a battery switch which isolates the >battery and alternator. They have found that alternator diodes blow when >this switch is opened while the field windings are still energized. The >alternator is charging into an open circuit. > > From the picture it looks that they are selling $0.70 transorb for $27.99. Jerzy ________________________________ Message 3 _____________________________________ Time: 09:31:42 AM PST US Subject: Re: AeroElectric-List: Shielded wire options From: John Schroeder --> AeroElectric-List message posted by: John Schroeder You can buy RG400 Coax from Wiremaster for $0.86/ft (Min. of 100 ft order) vs. $1.50 per ft. for a 100' buy at the source listed below. Wiremasters also has every gauge of 22759 and in almost every color for prices below any I have found. Most buys must be 100' min. They also have milspec M27500-xx TG x T14 (shielded hookup wire). Their 22 AWG 5 conductor is $.94/ ft and their 3 conductor (M27500-22TG3T14) is $.26 per foot. Call them at 800 635-5342. Ask for Deb Sullivan. Or email her at dsullivan@wiremasters.net Cheers, John > In that case I want to pass along this source of the least expensive > wire that will handle this application. They also stock various > connectors and antenna wire. > > http://www.thewireman.com/index.shtml > ________________________________ Message 4 _____________________________________ Time: 02:21:56 PM PST US From: "Terry Teer" Subject: AeroElectric-List: Wing wiring --> AeroElectric-List message posted by: "Terry Teer" Just about completed wings on a RV-7 and need some help. Installing landing light, position light, strobes (in fiberglass tips), nav/com antenna wiring (RG-400), also a roll servo for the a/p. Should I run all the wires through the 3/4 conduit or should some of them be separated from the rest? Also on the strobe heads...the whelen strobes say to ground the shielding to the power supply but in Bob's manual it says to ground the shielding wire to the strobe heads if mounting in plastic tips. What about it list? This is my second OBAM and the first to have more advanced equipment and need some advice. Regards, Terry Ackerman, MS