---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 07/26/05: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:58 AM - Re: Built-in starter contactor/Z-22 (Robert L. Nuckolls, III) 2. 05:09 AM - Re: New Chapter 18 (Robert L. Nuckolls, III) 3. 06:00 AM - Re: D-SUB Wye Band-Aid? (Matthew Brandes) 4. 06:49 AM - PTT coiled cord () 5. 07:05 AM - Re: Battery source(s) (Dj Merrill) 6. 11:57 AM - Re: Built-in starter contactor/Z-22 (John Swartout) 7. 02:27 PM - Re: Lycoming Alternator Kit on Ebay () 8. 07:38 PM - Cessna alternator regulator (Robert L. Nuckolls, III) 9. 07:41 PM - Re: Re: D-SUB Wye Band-Aid? (Robert L. Nuckolls, III) 10. 09:45 PM - Re: overvoltage protection false trigger fix (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:58:02 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Built-in starter contactor/Z-22 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:25 AM 7/26/2005 -0400, you wrote: >--> AeroElectric-List message posted by: "John Swartout" > > >Bob, I'm figuring to use Z13/8 with Z-22 for my Sky-Tec Flyweight >permanent magnet starter with onboard solenoid. > >In Note 10 you recommend locating the field breaker for the main >alternator (L40 with LR-3 in my case) not on the panel but as close as >possible to the starter contactor. That's not a field breaker but protection for the alternator's output wire commonly referred to as the "b-lead". > My starter RELAY will be on the >forward side of the firewall. This would make it impossible to pull the >breaker from the pilot's seat in case of alternator troubles. You'll never have a need to touch that FUSE (not breaker) in any conceivable failure scenario. > But if >the main alternator died, I would still like to be able to start the >engine if I am stuck 400 miles out in the bush, so I plan to use the >progressive transfer, 2-10 style master switch discussed in Note 22. It >is not clear to me whether it would still be possible to start the >engine if the L40 main alternator is disabled. Does it matter that >there is no jumper from the starter solenoid hot terminal to the B-lead >of the SD-8? Starter functionality has nothing to do with the wiring for either alternator. I'm not understanding your concerns >And should the wire size from the pushbutton starter to the S704-1 relay >be the same size as it would be for a starter contactor, i.e. 20AWG? It can be 22AWG >Thank you once again for your generous assistance. You're welcome. Bob . . . ________________________________ Message 2 _____________________________________ Time: 05:09:03 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: New Chapter 18 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 04:53 PM 7/25/2005 -0600, you wrote: >--> AeroElectric-List message posted by: mark supinski > > >I've read the new chapter 18 on audio panels, and it hits most of my >issues right on the head. The only thing it lacks is a picture of the >end result in terms of what is installed on the panel. > >Here is what I am trying to tie together: > >Comm1: (Garmin 250XL GPS/Comm) >Comm 2: (VAL 760) >Intercom: Sigtronics SPA 600 with optional stereo music module >Warning: Redish stall warner (have to create tone generator per chapter 18) >Music: Sirius satellite radio > >BX-2000 Audio selector panel > > >My basic question is - is it worth it (or even possible) to use the >BX-2000, or would I be better off to simply create something on my own >per chapter 18? The BX-2000 has lots of selections which I would have >no intention of using - so it fails the complexity proposed in ch >18... On the other hand, the audio isolator presented in ch 18 is mono >only it appears. > >As an aside, I wish there were a panel "after" drawing in Chapter 18 >to compare against the notional audio selector which is presented >early in the chapter. > >Help help! Depends on how many switches you WANT. It's quite practical to assemble an audio distribution system for your suite of goodies with but one switch . . . a DPDT toggle for transmitter selection. Indeed, this is suggested throughout the schematics in Chapter 18 where the only switches illustrated are transmitter selector switch and one or two push-to-talk buttons. This is why there are no figures illustrating the minimalist switch panel since it consists of a single switch labeled COMM 1 and COMM 2. If you want more switches, you can insert them into any audio pathway to add any degree of control you wish. However, I've suggested these are probably not necessary for practical operation of the system. A switch not present is NOT going to be the mis- positioned switch that prevents you from hearing something important. Bob . . . ________________________________ Message 3 _____________________________________ Time: 06:00:32 AM PST US From: "Matthew Brandes" Subject: AeroElectric-List: RE: D-SUB Wye Band-Aid? --> AeroElectric-List message posted by: "Matthew Brandes" Bob, I did this exact same wiring harness this past weekend (mine goes to Garmin 320 and a KLN-89B). Here is what I did that was a suggestion I got from another builder that worked out very well. (In your case, you'd have to cut the pins off one end and start over.) I ran the wires from the encoder to the transponder. On the transponder end of the wire, I stripped about 1/2"-5/8" of insulation off. I crimped on the pin. Then I positioned my wire strippers about 1.5" back from the end of the pin and 'pushed' the insulation up to the pin, exposing a section of wire. I then tinned this wire and soldered on a lead wire to run to the GPS. I put heat shrink over the connection. I also varied the location of the splices so there wasn't a big fat bundle. (What's Bob's phrase? " so it doesn't look like snake that ate the rabbit?".) If you need a picture, let me know. Matthew Brandes, Van's RV-9A (Wiring) #90569 http://www.n523rv.com EAA Chapter 1329 President EAA Chapter 868 Web Editor ________________________________ Message 4 _____________________________________ Time: 06:49:56 AM PST US From: Subject: AeroElectric-List: PTT coiled cord --> AeroElectric-List message posted by: The coiled cord used for cell phones to plug into the cigarette lighter is readily available at swap meets and flea markets here in Los Angeles. The wire is 24 gauge and it is untinned copper. Its what I am using now. I was hoping to fing something with tinned wire and aircraft quality. I would rather not have this cord be a "weak link" for my com radio. Sometimes even the most simple prosaic things can cause trouble. John Los Angeles, CA ________________________________ Message 5 _____________________________________ Time: 07:05:11 AM PST US From: Dj Merrill Subject: Re: AeroElectric-List: Battery source(s) --> AeroElectric-List message posted by: Dj Merrill Robert L. Nuckolls, III wrote: > Where do you live? In any medium size town (300K or more) Where do you live? I consider 300k to be a large city! *grin* do not archive -Dj, grew up in a town of pop. 2k -- Dj Merrill Sportsman 2+2 Builder #7118 "TSA: Totally Screwing Aviation" ________________________________ Message 6 _____________________________________ Time: 11:57:08 AM PST US From: "John Swartout" Subject: RE: AeroElectric-List: Built-in starter contactor/Z-22 --> AeroElectric-List message posted by: "John Swartout" -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: RE: AeroElectric-List: Built-in starter contactor/Z-22 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:25 AM 7/26/2005 -0400, you wrote: >--> AeroElectric-List message posted by: "John Swartout" > > >Bob, I'm figuring to use Z13/8 with Z-22 for my Sky-Tec Flyweight >permanent magnet starter with onboard solenoid. > >In Note 10 you recommend locating the field breaker for the main >alternator (L40 with LR-3 in my case) not on the panel but as close as >possible to the starter contactor. That's not a field breaker but protection for the alternator's output wire commonly referred to as the "b-lead". Okay--that paragraph in Note 10 continues to refer to the ANL current limiter, not the field breaker. I was thrown off by the change to Alternator Breaker in that paragraph. > My starter RELAY will be on the >forward side of the firewall. This would make it impossible to pull the >breaker from the pilot's seat in case of alternator troubles. You'll never have a need to touch that FUSE (not breaker) in any conceivable failure scenario. > But if >the main alternator died, I would still like to be able to start the >engine if I am stuck 400 miles out in the bush, so I plan to use the >progressive transfer, 2-10 style master switch discussed in Note 22. It >is not clear to me whether it would still be possible to start the >engine if the L40 main alternator is disabled. Does it matter that >there is no jumper from the starter solenoid hot terminal to the B-lead >of the SD-8? Starter functionality has nothing to do with the wiring for either alternator. I'm not understanding your concerns I think I'm not seeing how the misbehaving main alternator would be isolated during engine start. It may be that if the S700-2-10 were illustrated in Z13/8 instead of the S700-2-3 as the DC Power Master Switch, it might be clear to me. Do you have a drawing showing how that switch would be wired? >And should the wire size from the pushbutton starter to the S704-1 relay >be the same size as it would be for a starter contactor, i.e. 20AWG? It can be 22AWG >Thank you once again for your generous assistance. You're welcome. Bob . . . ________________________________ Message 7 _____________________________________ Time: 02:27:40 PM PST US From: Subject: AeroElectric-List: Re: Lycoming Alternator Kit on Ebay --> AeroElectric-List message posted by: Looks nice but it shows an external regulator ( a good one), but the text says internal regulated. I would ask? Either way it looks like a new 50 amp Denso, which is the typical one most people use. New just the alternator goes for $90-$140. The brackets look nice if you have a narrow deck. Love ebay, but with anything buyer beware. $199 is not a steal since niagara airparts sells their 40amp kit for about that, but if you need this it looks OK to me. George >Subject: Lycoming Alternator Kit on Ebay From: >Gerry Holland >FYI >I spotted a Lycoming Alternator Kit on Ebay at starting bid at $199. http://cgi.ebay.com/ebaymotors/LYCOMING-HOMEBUILT-AIRCRAFT-ALTERNATOR-KIT_W0QQitemZ4564658670QQcategoryZ26437QQrdZ1QQcmdZViewItem >Ensure the whole URL copied to Browser Thought someone may be in the market to buy. >Regards Gerry ________________________________ Message 8 _____________________________________ Time: 07:38:38 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Cessna alternator regulator --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >Comments/Questions: I have a1968 Cessna 150. After rteading your excellent >book I wonder if I should replace the original Voltage regulator even >though its working fine ? Maybe I should just buy a spare. > >I understand the originals were simply Delco products for the '65 Chevy or >similar. > >What would you suggest please? Cessna's single engine regulators and alternators have a Ford pedigree. The original regulators installed were of the electro-mechanical variety that looked like this: http://www.aeroelectric.com/Pictures/Ford_EM_Reg_Exterior.jpg and http://www.aeroelectric.com/Pictures/Ford_EM_Reg.jpg the automotive world has some solid state equivalents that are very inexpensive and have been used in a lot of owner built and maintained (OBAM) aircraft like: http://www.aeroelectric.com/Pictures/Ford_SS_Reg.jpg http://www.aeroelectric.com/Pictures/Ford_SS_Reg_open.jpg However, I would be cautious with modern substitutes because behavior of the modern regulators when teamed with the overvoltage protection module used in the Cessnas can produce some very anomalous behavior including tendency of the regulator to go into OV condition instead of shutting off. These are NOT form-fit-function replacements for the Ford electro-mechanical regulators as-installed in Cessna aircraft. Your airplane is wired per the first diagram you can find in Zeftronics product literature for a modern solid state replacement for your regulator at: http://www.aeroelectric.com/Mfgr_Data/Zeftronics/R15V00-PIT.pdf Acquiring a new regulator is no big deal. If your present regulator is working, there's no reason I can deduce to replace it. I WOULD, HOWEVER, recommend bench checking the over voltage protection module that wired in series with pin "S" on your present regulator. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 9 _____________________________________ Time: 07:41:07 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: D-SUB Wye Band-Aid? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:58 AM 7/26/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "Matthew Brandes" > > >Bob, > >I did this exact same wiring harness this past weekend (mine goes to Garmin >320 and a KLN-89B). Here is what I did that was a suggestion I got from >another builder that worked out very well. (In your case, you'd have to cut >the pins off one end and start over.) > >I ran the wires from the encoder to the transponder. On the transponder end >of the wire, I stripped about 1/2"-5/8" of insulation off. I crimped on the >pin. Then I positioned my wire strippers about 1.5" back from the end of >the pin and 'pushed' the insulation up to the pin, exposing a section of >wire. I then tinned this wire and soldered on a lead wire to run to the >GPS. I put heat shrink over the connection. I also varied the location of >the splices so there wasn't a big fat bundle. (What's Bob's phrase? " so it >doesn't look like snake that ate the rabbit?".) > >If you need a picture, let me know. Matthew's technique is exactly what I would have suggested. There are some sexier ways to do this all of which get bulky, more expensive and drive up parts count. Some times the best way to drive a nail is with a hammer . . . and to connect some wires is with a bit of solder. Works good, costs next to nothing and lasts a long time. Bob . . . ________________________________ Message 10 ____________________________________ Time: 09:45:00 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: overvoltage protection false trigger fix --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:40 AM 7/24/2005 -0400, you wrote: >--> AeroElectric-List message posted by: Ken > > I had a false OVM trip thing going on similar to Tom Johnson and I >really get annoyed when simple circuits misbehave. Both of my homemade >OVM's would trip their 2.5 amp C/B on battery power without the engine >running when various switches were operated. I couldn't make anything >trip when the OVM's were disconnected and I do have diodes on all the >relays. This is on a modified Z-14 and it turns out that my OVM's are >constructed according to reivision B 6/29/04 with that detailed >explanation of the circuit. > >If I removed the main battery or it's B-lead fuse then just turning on >the crossfeed would trip both OVM's almost everytime. Interestingly both >C/B's are in series with a 10 amp ATO fuse and despite many dozens of >2.5 amp C/B trips I've yet to pop a 10 amp fuse. I did not see anything >unusual with an analog scope although on the bench the scope sure shows >how the diodes across the relays eliminates the negative spike when the >relays are opened. The OVM's seemed to check out fine on my bench and >and in fact I was only been able to get one unrepeatable false trip on >the bench and that was by drawing a little arc for quite some time in >the connection to the relay coil. > >I then started thinking that maybe this really is the dv/dt effect on >the SCR due to voltage spikes on the bus. So I disconnected the >tranistor from the SCR gate but no false triggering occurred which I >think that means that the dv/dt effect was NOT occurring. However while >investigating (poking around) I noticed that just touching a digital >voltmeter probe to point C (the zener) would often trigger the little >devil. That didn't seem right so I added a 10 uF aluminum cap to >stabilize/filter the 12 volt reference provided by the zener. (No >particular reason for 10 uF , I just happened to put my hand on one) >Well happy days, it seems to have done the trick as so far I have not >been able to false trip the device. > >Bob I'm going to declare my problem fixed unless you still want to see >one of these OVM's for your own tests. Maybe my particular zeners are >slow learners but it seems to me that the voltage reference probably >should have a capacitor on it to reduce its sensitivity to bus >variations and in any event, that seems to have fixed my problem :) > >thanks >Ken Ken, Your observations and analysis are dead-on and more profound than you probably know. The original ov protection system used a two-wire, 4-layer trigger device (MBS4991) which was as vulnerable to dv/dt triggering as an SCR but isolated from those effects by the strong response roll-off of of the voltage divider and time delay characteristics of the input calibration network. When the MBS4991 went obsolete, we needed a quick substitute where synthesis of a 4-layer, voltage sensitive device was accomplished with two transistors, a couple of resistors and a zener. This more complex circuit found its way into a number of versions of the B&C regulators. This 3-wire network sampled bus voltage as part of the Vref circuit which opened another gateway with a potential for sensitivity to dv/dt. Your discovery and analysis published above was something of an epiphany because I didn't recall how a voltage reference was supplied to the ov protection system in the production regulators. Your work illuminated the potential for problems in the production products. An inspection of schematics for those products showed that Vref for the network comes off a precision voltage reference bypassed with a capacitor. Therefore, the 'fix' you described above was already present in the B&C products but overlooked in my published drawings for a DIY ov protection system. I'm modifying the DIY circuit for publication over the next day or so to incorporate the benefits of your discovery. Ken, the benefits realized from this exchange of simple ideas is a great example of how the collective efforts of individuals can work in ways individual efforts cannot. Your discovery is very rudimentary, simple and seems like it should be an "obvious" concept. But folks who have worked as creative professionals understand how easy it is for things like this to slip by unnoticed. Your discovery is a significant addition to a considered critical review process of a condition that could have wide influence on the systems installed in many airplanes. I'm grateful for your ability and willingness to bring this condition to light. Further, I'd like to use this experience as a working example of what I've been trying to explain about how cooperative, considered critical review pushes the art and science of our craft ahead in quantum jumps. I'll beg your indulgence in allowing me to showcase your contribution and ask your assistance in encouraging others to contribute with the same spirit and goals in mind. I'm adding a new feature to aeroelectric.com that will showcase this experience as the first of what I hope will become a long series of exchanges between two or more individuals here on the list where a simple (but profound) idea comes to light with benefits to anyone who chooses to exploit it. I'll catalog and archive the posts that describe these experiences as a special new feature. Individual(s) contributions will be acknowledged by addition of the thread to the archive and issuance of Certificates of Recognition issued by the AeroElectric Connection. I'll reserve the right to make final determination and selection of items to be so recognized but I encourage ANY participant on the AeroElectric-List to nominate any simple-idea and discussion participants for special recognition. The first certificate of this series has been posted in your name and may be downloaded from http://www.aeroelectric.com/Awards/Certificates/001_Ken_Lehman.pdf Thank you so much for sharing your insight and skills on the AeroElectric List. Bob . . .