---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 02/05/04: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:22 AM - Re: Converting a Mitsu Alternator #2 (Charlie Kuss) 2. 06:33 AM - Re: Converting a Denso Alternator (Robert L. Nuckolls, III) 3. 10:30 AM - ov protection for internal v.r. alternators (Glen Matejcek) 4. 10:45 AM - Re: 11133 Hersha (Robert L. Nuckolls, III) 5. 11:52 AM - RG400 (Ken Simmons) 6. 04:00 PM - Re: RG400 (Robert L. Nuckolls, III) 7. 04:02 PM - ov protection for internal v.r. alternators (Robert L. Nuckolls, III) 8. 05:10 PM - Re: Converting a Denso Alternator (Jerzy Krasinski) 9. 08:30 PM - Re: Re: 11133 Hersha <5.0.0.25.2.20040204215217.015c1920@pop.central.cox.net> (Scott Hersha) 10. 09:23 PM - OV Protection for Internally Regulated .. Another Question (James E. Clark) 11. 10:48 PM - Shielded wire options (hollandm) ________________________________ Message 1 _____________________________________ Time: 05:22:59 AM PST US From: Charlie Kuss Subject: Re: AeroElectric-List: Converting a Mitsu Alternator #2 --> AeroElectric-List message posted by: Charlie Kuss The blurry photos are due to the fact that this article was faxed to me. Charlie >--> AeroElectric-List message posted by: Jerzy Krasinski > >I opened my internaly regulated Mitsubishi, and I found one irregular >block containing the brush holders and regulator, all epoxy potted >inside a fragile looking piece of plastic. I thought about milling out >the regulator but it is very difficult to hold that thing in the mill, >and it looked that I would have to make a new brush holder from >scratch. I have spent a day looking at it and I gave up. I put the >alternator back together and I will try to attach transorbs or a big >varistor for protection. The problem is that information about the >transients included in http://www.sto-p.com/pfp/pfp-transients.htm#load > is showing voltage approaching 100V and internal resistance of the >source between 0.1 and 1 ohm. That would imply that current through the >varistor or transorb limiting output voltage to several volts could >reach several hundreds amps. That does not seem to make any sense, I >would expect that the alternator would try to make the output current >equal to the current just before removal of the load, and such current >would reduce the peak voltage down to the normal output voltage. > > I will connect the protective elements and we will see if it works. > >Anyway, my Mitsubishi is nearly impossible to convert in a simple way. >But maybe somebody solved that problem? I would appreciate some info. >Thank you, >Jerzy ________________________________ Message 2 _____________________________________ Time: 06:33:57 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Converting a Denso Alternator --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:14 PM 2/4/2004 -0600, you wrote: >--> AeroElectric-List message posted by: Jerzy Krasinski > > >I opened my internaly regulated Mitsubishi, and I found one irregular >block containing the brush holders and regulator, all epoxy potted >inside a fragile looking piece of plastic. I thought about milling out >the regulator but it is very difficult to hold that thing in the mill, >and it looked that I would have to make a new brush holder from >scratch. I have spent a day looking at it and I gave up. I put the >alternator back together and I will try to attach transorbs or a big >varistor for protection. The problem is that information about the >transients included in http://www.sto-p.com/pfp/pfp-transients.htm#load > is showing voltage approaching 100V and internal resistance of the >source between 0.1 and 1 ohm. That would imply that current through the >varistor or transorb limiting output voltage to several volts could >reach several hundreds amps. That does not seem to make any sense, I >would expect that the alternator would try to make the output current >equal to the current just before removal of the load, and such current >would reduce the peak voltage down to the normal output voltage. Your thinking rationally now Jerry, gotta be careful around those who preach the gospel of doom-n-gloom. I think we know that an alternator is incapable of delivering more than its magnetics are designed for . . . even in a transient condition. So a battery-dump event would be limited to perhaps 10-20% more than the alternator's current rating. Also, I think the time constants cited are rather long and predicated on effects of system loads . . the effect we're intently interested in is an intentionally generated battery-dump when the disconnect contactor is opened and the alternator is totally unloaded. Like you, I've read all the literature designed to convince us that a happy world has transorbes sprinkled all over it, and gee, if little ones are good, fat ones are better. Let's keep stirring the pot with good science and repeatable experiments. This can be good stew yet. > I will connect the protective elements and we will see if it works. Are you planning an experiment with measurements? >Anyway, my Mitsubishi is nearly impossible to convert in a simple way. >But maybe somebody solved that problem? I would appreciate some info. That's not uncommon. The moldings that hold brushes and regulators tend to be integrated in ways that make it difficult to remove regulators and re-wire brushes. Bob . . . ________________________________ Message 3 _____________________________________ Time: 10:30:52 AM PST US From: "Glen Matejcek" Subject: AeroElectric-List: ov protection for internal v.r. alternators --> AeroElectric-List message posted by: "Glen Matejcek" Hi Bob and list- Something has occurred to me. While I've never been inside a ND alternator, and am certainly no guru of any sort, I have an idea I'd like your feedback on. It seems to me that the fundamental problem with regard to OV protection on these internally regulated alternators is the inability to cut the supply of power to the field during an OV event. How hard / appropriate would it be to open the regulator up, find the wire that feeds the field, cut it, bring the two resultant lines out of the case to a relay and a B&C OV module? When the system goes OV, power is removed from the field. It seems so simple, I feel like I'm missing something.... gm ________________________________ Message 4 _____________________________________ Time: 10:45:19 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: 11133 Hersha <5.0.0.25.2.20040204215217.015c1920@pop.central.cox.net> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:52 AM 2/5/2004 -0500, you wrote: >I haven't tried the separate battery yet, that's my next experiment. The >radio noise does not go away if I disconnect the antenna - either radio, >either antenna. Squelsh is automatic and not controlable from the front of >the panel. I have 2 VAL COM 760's. Cheap radios, but I wanted 2 and I've >never had a problem with them in the past. . . . and I've never heard of them being a "problem" radio. I'm thinking there may be something basic the architecture of you system that's causing the problem. >My kit from Radio Shack (I'm building 3) came with a 220 micro farad >capacitor. Your plans diagram shows a 10 micro farad capacitor to be used. >Should I use the one supplied or go get the 10 micro farad? the kit should have come with the 10uf cap. If you have larger caps you want to use, that's fine too. Bob . . . ________________________________ Message 5 _____________________________________ Time: 11:52:28 AM PST US From: "Ken Simmons" Subject: AeroElectric-List: RG400 --> AeroElectric-List message posted by: "Ken Simmons" Sorry, but I've researched myself into a state of confusion and was hoping you guys could help me out. I'm not to the point of installing avionics yet, but a buddy is finishing up his RV-6 and is asking for help finishing up his avionics install. I've got connectors and tools (fancy stripper and crimper) for RG-58 cable, but he is using RG400. I've never worked with RG400 before. First, the connectors. I've seen some sites that indicate a single connector for RG58 or RG400. Other sites specify a different connector for the two. Is there really that big of a difference? It seems like there is no reasonable way to tie to the second shield in the RG400 anyway with a crimp connector. The other question on the stripper. It's one where you rotate a die for RG6/RG58/RG59. It seems reasonable to me that the blades could be adjusted, if necessary, with the RG58 position to get a good strip on the RG400. Again it kind of depends on the second shield on the RG400. Thanks for the help. Ken DO NOT ARCHIVE ________________________________ Message 6 _____________________________________ Time: 04:00:40 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RG400 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:00 PM 2/5/2004 -0700, you wrote: >--> AeroElectric-List message posted by: "Ken Simmons" > >Sorry, but I've researched myself into a state of confusion and was hoping >you guys could help me out. > >I'm not to the point of installing avionics yet, but a buddy is finishing >up his RV-6 and is asking for help finishing up his avionics install. I've >got connectors and tools (fancy stripper and crimper) for RG-58 cable, but >he is using RG400. I've never worked with RG400 before. > >First, the connectors. I've seen some sites that indicate a single >connector for RG58 or RG400. Other sites specify a different connector for >the two. Is there really that big of a difference? It seems like there is >no reasonable way to tie to the second shield in the RG400 anyway with a >crimp connector. It depends on the tolerances of the specific connector. MOST connectors for RG400 will work with RG58 also. The connectors and tools offered by B&C work with both coaxes. >The other question on the stripper. It's one where you rotate a die for >RG6/RG58/RG59. It seems reasonable to me that the blades could be >adjusted, if necessary, with the RG58 position to get a good strip on the >RG400. Again it kind of depends on the second shield on the RG400. Yup, I've got a stripper that was supposedly set up for RG58 and it does a better job on 400. A little practice with a scrap of RG400 with an Xacto and #11 blade will do good too. Bottom line is don't make the first attempt at a new combination of tools and technologies the one that goes on your airplane. Get some extra connectors, pins, etc and see how well they work and what techniques you may need to refine to do the best job. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 7 _____________________________________ Time: 04:02:18 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: ov protection for internal v.r. alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:30 PM 2/5/2004 -0500, you wrote: >--> AeroElectric-List message posted by: "Glen Matejcek" > > >Hi Bob and list- > >Something has occurred to me. While I've never been inside a ND >alternator, and am certainly no guru of any sort, I have an idea I'd like >your feedback on. It seems to me that the fundamental problem with regard >to OV protection on these internally regulated alternators is the inability >to cut the supply of power to the field during an OV event. How hard / >appropriate would it be to open the regulator up, find the wire that feeds >the field, cut it, bring the two resultant lines out of the case to a relay >and a B&C OV module? When the system goes OV, power is removed from the >field. It seems so simple, I feel like I'm missing something.... Any modification to that end would be satisfactory . . . once you're inside, it's just about as easy to completely remove the built in regulator and bring out the field leads like the B&C mods. After that, you have MANY options for regulators and ov protection. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 8 _____________________________________ Time: 05:10:53 PM PST US From: Jerzy Krasinski Subject: Re: AeroElectric-List: Converting a Denso Alternator --> AeroElectric-List message posted by: Jerzy Krasinski Jerzy Krasinski wrote: I will connect the protective elements and we will see if it works. Robert L. Nuckolls, III wrote: > Are you planning an experiment with measurements? > > > I just got a bunch of protective diodes and the biggest varistors I could get for a reasonable price. Unfortunately there is a 20X price jump for really big ones. However, it seems much more cost effective to put several smaller varistors in parallel. The choise between the diodes and varistors is difficult. Varistors are almost indestructible, but they have more gradual characteristics. That means they are likely to allow a bigger voltage increase in the conditions of a dump. Diodes have sharper current increase with voltage, but they are more fragile and they fail making a short, if they get too much energy. Such a short would not be nice. The solution is to put many of them in parallel - if I can isolate several similar diodes from the bunch I got.. In the mean time I keep reading whatever was written about the alternators. I do not have at home capabilities to check the protective devices in a pulsed way for high current. I will try to do that somewhere else. I will select more promising elements and attach them to the alternator hoping for the best. Jerzy ________________________________ Message 9 _____________________________________ Time: 08:30:48 PM PST US From: "Scott Hersha" Subject: Re: AeroElectric-List: Re: 11133 Hersha <5.0.0.25.2.20040204215217.015c1920@pop.central.cox.net> --> AeroElectric-List message posted by: "Scott Hersha" Bob, I'm making 3 of the noise filters I got at Radio Shack, however they will not be as pretty as the one you made. When I snipped the choke leads shorter per plans I was left with two untinned copper wires. It was nearly impossibe to get solder to stick to the bare copper when soldering a tinned wire to it. I'm using a 30 watt iron and the kind of solder you recommended. The next two I made, I didn't cut the choke leads down so I could use the tinned ends. I had to wrap the choke wires over the top and glue the cap on the other side of the coil. I'll still run the wires through the coil gap and use a lot of glue to provide strain relief, but it will be a little less professional looking than yours. I just hope it works. Scott Hersha ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: 11133 Hersha <5.0.0.25.2.20040204215217.015c1920@pop.central.cox.net> > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 08:52 AM 2/5/2004 -0500, you wrote: > >I haven't tried the separate battery yet, that's my next experiment. The > >radio noise does not go away if I disconnect the antenna - either radio, > >either antenna. Squelsh is automatic and not controlable from the front of > >the panel. I have 2 VAL COM 760's. Cheap radios, but I wanted 2 and I've > >never had a problem with them in the past. > > . . . and I've never heard of them being a "problem" radio. > I'm thinking there may be something basic the architecture > of you system that's causing the problem. > > >My kit from Radio Shack (I'm building 3) came with a 220 micro farad > >capacitor. Your plans diagram shows a 10 micro farad capacitor to be used. > >Should I use the one supplied or go get the 10 micro farad? > > the kit should have come with the 10uf cap. If you have larger > caps you want to use, that's fine too. > > Bob . . . > > ________________________________ Message 10 ____________________________________ Time: 09:23:27 PM PST US From: "James E. Clark" Subject: AeroElectric-List: OV Protection for Internally Regulated .. Another Question --> AeroElectric-List message posted by: "James E. Clark" There has been a LOT of dialog along the lines mentioned below (opening up the alternator). I have looked but probably overlooked it so my question is: Is there a *summary* recommendation (or opinion) on what one could reasonably do to get additional protection WITHOUT opening the alternator???? The one is question is the 55 amp model from Van's. Thanks, James [snip] > > > >Something has occurred to me. While I've never been inside a ND > >alternator, and am certainly no guru of any sort, I have an idea I'd like > >your feedback on. It seems to me that the fundamental problem > with regard > >to OV protection on these internally regulated alternators is > the inability > >to cut the supply of power to the field during an OV event. How hard / > >appropriate would it be to open the regulator up, find the wire > that feeds > >the field, cut it, bring the two resultant lines out of the case > to a relay > >and a B&C OV module? When the system goes OV, power is removed from the > >field. It seems so simple, I feel like I'm missing something.... > > Any modification to that end would be satisfactory . . . once you're > inside, it's just about as easy to completely remove the built in > regulator and bring out the field leads like the B&C mods. > > After that, you have MANY options for regulators and ov protection. > > Bob . . . > > ________________________________ Message 11 ____________________________________ Time: 10:48:27 PM PST US From: "hollandm" Subject: AeroElectric-List: Shielded wire options --> AeroElectric-List message posted by: "hollandm" In choosing shielded wire to hook up the radio jacks I've used some relatively inexpensive stuff that I found. Rather than the hightech stuff with braided shields this wire has a mylar foil, with a bleed wire. Is this an acceptable to use for audio hookups? I'm intend to use it to connect the Dynon external mag compass, which has been alleged to induce EMI problems. I don't want to cut corners when it makes a difference in safety, performance or reliability. Thanks