---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 09/12/05: 27 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:00 AM - Re: Use a 28vdc alternator in 14vdc system? (Charlie England) 2. 12:27 AM - Re: Parts to build the OV protector (Robert L. Nuckolls, III) 3. 12:28 AM - Re: Crowbar OVM schematic version? (Robert L. Nuckolls, III) 4. 06:02 AM - Re: Use a 28vdc alternator in 14vdc system? (Robert L. Nuckolls, III) 5. 06:15 AM - Re: Crowbar CB "problem" question (Robert L. Nuckolls, III) 6. 06:31 AM - Re: elec smoke smell (Guy and Jill Foreman) 7. 07:10 AM - Re: LED annunciator lamps (rv-9a-online) 8. 08:01 AM - Re: Parts to build the OV protector (Robert L. Nuckolls, III) 9. 08:11 AM - Re: Re: Noise Filter for 5 lead motor (Robert L. Nuckolls, III) 10. 08:45 AM - Bringing alternator on line after engine start. (Rogers, Bob J.) 11. 09:22 AM - Re: Re: Noise Filter for 4 lead motor (revenson@comcast.net) 12. 11:57 AM - Re: Re: RV 10 wiring architecture (Dave & Brenda Emond) 13. 12:24 PM - Re: Crowbar CB "problem" question (Paul Messinger) 14. 01:39 PM - Inexpensive source for heat shrink tubing for Kroy, KSun labers () 15. 02:19 PM - Dumb question time (Hinde, Frank George (Corvallis)) 16. 02:51 PM - Re: Inexpensive source for heat shrink tubing (Bob White) 17. 03:05 PM - Re: Inexpensive source for heat shrink tubing (Jim Streit) 18. 03:18 PM - Re: Dumb question time (Matt Prather) 19. 03:43 PM - ARC R402A Marker Pin out (Bill and Marsha) 20. 05:08 PM - PM alternator on Mazda engine. (William) 21. 05:23 PM - Re: Crowbar CB "problem" question (Kevin Horton) 22. 05:38 PM - Re: Crowbar CB "problem" question (D Wysong) 23. 06:02 PM - Re: Crowbar OVM schematic version? (D Wysong) 24. 07:54 PM - Power FET's (Paul McAllister) 25. 08:15 PM - Re: Power FET's (Robert L. Nuckolls, III) 26. 08:18 PM - Re: Crowbar OVM schematic version? (Robert L. Nuckolls, III) 27. 08:31 PM - Re: Power FET's (D Wysong) ________________________________ Message 1 _____________________________________ Time: 12:00:01 AM PST US From: Charlie England Subject: Re: AeroElectric-List: Use a 28vdc alternator in 14vdc system? --> AeroElectric-List message posted by: Charlie England Robert L. Nuckolls, III system? wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" system? > >At 02:07 PM 9/10/2005 -0500, you wrote: > > > >>--> AeroElectric-List message posted by: >> >> >> >> >>>From: "Bruce Gray" >>>Date: 2005/09/08 Thu PM 09:56:40 CDT >>>To: >>>Subject: RE: AeroElectric-List: Use a 28vdc alternator in 14vdc system? >>> >>>--> AeroElectric-List message posted by: "Bruce Gray" >>> >>>How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero >>> >>>Bruce >>>www.glasair.org >>> >>> >>Do you fly a Cessna or RAC a/c? Why is their opinion better for electrical >>systems if it's not better for a/c selection? ;-> >> >> > > Gently Charlie, we know the BePipCesMo guys are hard pressed > just to stay in business under the worst of economic and working > conditions; making detailed evolutionary refinements in on-board systems > is simply impossible. Virtually EVERY decision for making changes > has to be made under the albatross of, "what will it cost us to get > dispensation and blessings from the East?" I'm told the cost > of implementing a change to one sheet of paper describing a part > of our products can cost 5 to 7 $thousands$ by the time everyone > in our business with an interest in that part is properly aware > of the change and the changes are carved into the stone of what > has been euphemistically called "configuration management." > > I've had conversations with my contemporaries at RAC about what > goes on in the OBAM aviation community and nearly to a man, > they all look wistful and say, "Gee . . . I wish we could > do that out here." If any of us could make a living in OBAM > aircraft, we'd all be working for somebody else but the BePipCesMo > crowd. Alas, that same over-regulated, exclusively marketed line > of products is still producing a huge cash flow. As long as > that river of cash is sufficient for each of us to get a tiny > hook into it and snag off enough for a living, we'll hang around. > > There are still some fun days. Took a Saturday morning today to > put my data acquisition system on a Beechjet and track down > a malfunction in a tail deice system. This problem has plagued > my boss and the airplane's owners for months. They've already > spent a bucket of money on the usual but inadequate isolation > techniques. There are few things that will bring me out to > the airport on Saturday morning (or in an ice storm) and this > was one of them. It was a GREAT day. > > In the mean time, let's be mindful of what's gone before us > both for the rich history of experience and as environments > for learning. We are all graduating from "Certified U" and striking > out on our own. Some of us will found new institutions. Some > will be successful, others will not. But our mission here on the > List should not be to judge ACTIONS of either OBAMdom or SPAMdom > but to glean the simple-ideas from both that will provide > foundation for building beyond where we are today in EITHER > venue. The fact that a BE36 currently has a 14 or 28v system is > irrelevant. What is relevant are the tradeoffs for the two > systems in the ways we intend to apply them in an RV or > Glasair and the selection of "tinker-toys" available > to us for implementation of what ever decision is made. > > I'd love to take a stripped-out BE-36 and do a clean-slate > systems installation. I'm sure we could take out lots of weight, > add lots of value and maybe even pump some new market life > into that venerable ol' beast . . . but some nicely built > RV will still outrun it. BTW, it would still have a 28v, 100A > and 20A alternators on it. Too much need for electric heat. > > Bob . . . > Sorry; that was intended to be a little good natured kidding & must have been a bit too...concise. My thought was very similar to yours: the factory decision making is driven by many factors that we don't have to consider & we have the freedom to do what's best for our a/c, not driven by big business/certification issues. For example, I don't use a certified battery, or certified air/oil separator, etc, etc in my RV-4, even though all the factory guys have to. If the original poster's *only* criteria for designing an electrical system is 'What would RAC/Cessna do?' then it can logically follow that RAC/Cessna can also answer the question, 'What airplane should I fly?' for him. Charlie ________________________________ Message 2 _____________________________________ Time: 12:27:51 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Parts to build the OV protector --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:24 AM 9/11/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > >At 10:43 AM 9/11/2005 -0400, you wrote: > > >--> AeroElectric-List message posted by: > > > >I was going to try and build the OV crowbar module as suggested by Bob. I > >discovered that the MBS4991 is an invalid part number with Digikey and they > >only have two of the other parts in stock. With a $5 handling charge, I > >need to get the complete order if possible. > > > >Can someone tell me part numbers and sources for these parts? I am not an > >electrician, so I don't even know what the part that they don't have is, > >since I don't understand the symbol in the drawing. > > > >The resistors I suppose I could get at Radio Shack, maybe the diode and the > >potentiometer? > > Your looking at a very old version which utilized a part > now obsolete. The latest version will be published later > today or tomorrow. I've updated the schematics and BOM > and thought I'd got them posted but an astute reader > pointed out the error of that impression a couple of > days ago. I'll try to get caught up this evening. Done. Download . . . http://aeroelectric.com/articles/Crowbar_OV_Protection/Crowbar_C.pdf Bob . . . ________________________________ Message 3 _____________________________________ Time: 12:28:08 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar OVM schematic version? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" D, Thanks for "picking the nits" . . . I thought I'd updated that page. See: http://aeroelectric.com/articles/Crowbar_OV_Protection/Crowbar_C.pdf Bob . . . At 01:21 PM 9/8/2005 -0500, you wrote: >--> AeroElectric-List message posted by: D Wysong > >Howdy Bob - > >FYI (from a nitpickin' proof reader) - it seems that an older schematic >and BOM snuck back onto page 1 of the Crowbar OVM document (02/20/01): > >http://aeroelectric.com/articles/crowbar.pdf > >I dug out a schematic from 06/29/04, but I figured there might be an >even later revision to reflect Ken's contribution. No? > >Thanks, > >D > > >-- > > >-- incoming mail is certified Virus Free. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________ Message 4 _____________________________________ Time: 06:02:44 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Use a 28vdc alternator in 14vdc system? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >Sorry; that was intended to be a little good natured kidding & must have >been a bit too...concise. My thought was very similar to yours: the >factory decision making is driven by many factors that we don't have to >consider & we have the freedom to do what's best for our a/c, not driven >by big business/certification issues. For example, I don't use a >certified battery, or certified air/oil separator, etc, etc in my RV-4, >even though all the factory guys have to. > >If the original poster's *only* criteria for designing an electrical >system is 'What would RAC/Cessna do?' then it can logically follow that >RAC/Cessna can also answer the question, 'What airplane should I fly?' >for him. No big deal. There's always a risk with "one liners" that the spirit and intent can be left open to supposition and at least half the readers will get it wrong! I wasn't real sure . . . it would have helped me to consider the icon at the end . . . being an engineer tasked with communication by precise speech, I miss those things from time to time. Thank you for the follow up! Bob . . . ________________________________ Message 5 _____________________________________ Time: 06:15:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar CB "problem" question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > AeroElectric-List message previously posted by: Richard Riley > > > > > > < > particularly one of the B&C regulators - how often do the nuisance > > trips occur? > > > > If we're worried about the nuisance trips degrading field CB's, would > > it be a reasonable fix to replace those CBs at annual?>> There are rumors suggesting that some breakers are severely overtaxed by the crowbar event that forces them open when using this particular technology for ov protection. I have researched this allegation extensively. I've produced many documents to combine with my personal anecdotal experience going back 25 years that will not support the allegation for the types of circuit breakers commonly used in the Spam Can and OBAM aircraft industries. The field breaker on B&C's regulator test stand got replaced after about ten years of testing running over 1000 regulators that were deliberately tripped as part of the acceptance test procedure. I can find no substantive concerns about breaker life in this application. Real problems have been rare and addressed as soon as individuals experiencing problems brought it to our attention. If the rate of problem events with components and systems on bizjets were as low as for the crowbar system, I'd be out of a job. Bob . . . ________________________________ Message 6 _____________________________________ Time: 06:31:06 AM PST US From: "Guy and Jill Foreman" Subject: Re: AeroElectric-List: elec smoke smell --> AeroElectric-List message posted by: "Guy and Jill Foreman" Thanks for the advise. I'll try this today. thanks, guy >From: "Robert L. Nuckolls, III" >Reply-To: aeroelectric-list@matronics.com >To: aeroelectric-list@matronics.com >Subject: Re: AeroElectric-List: elec smoke smell >Date: Sun, 11 Sep 2005 21:41:32 -0500 > >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > >At 06:30 PM 9/10/2005 -0700, you wrote: > > >--> AeroElectric-List message posted by: Richard Riley > > > > >Others will, I'm sure, have better suggestions. But I'd start off > >with have a halon extinguisher handy. > > > > > >At 05:15 PM 9/10/05, Guy and Jill Foreman wrote: > > > > >--> AeroElectric-List message posted by: "Guy and Jill Foreman" > > > > > > > > >I turned on my split batt/alt switch, and heard a rapid clicking noise, > > >followed by a elec smoke smell. I turned of the batt switch, and the >smell > > >went away. I decided to replace the batt relay, but never did find out >where > > >the smell was coming from. I know something got hot, but cant find >where it > > >came from. Any suggestions? > > Pull all fuses/breakers. Install a temporary fuse in > series with your battery. I recommend a MAX30 and HHX inline holder > like the one on page 12 of > >http://www.bussmann.com/shared/library/catalogs/Buss_Auto-Fuse_Cat.pdf > > You can find these at many car parts stores. > > Power system up battery only. Push breakers in/install fuses in one > system at a time and test each one for functionality. When a system > has been checked, pull that fuse/breaker back out. If you can't locate > a "dead" system, then hook some kind of visual or audible indicator > to the downstream side of your MAX30 and start pushing and pulling > on things. You're looking for something loose and/or cut wherein > the original fault cleared when you smelled smoke the first time. > You're trying to get it to repeat but without smoke this time. > > Bob . . . > > ________________________________ Message 7 _____________________________________ Time: 07:10:41 AM PST US From: rv-9a-online Subject: Re: AeroElectric-List: LED annunciator lamps --> AeroElectric-List message posted by: rv-9a-online Dave, you must have had fun building your annunciator system. It would be interesting to get more details. These kind of alarm functions are also contained in even simple engine monitors, such as the Rocky Mountain or Grand Rapids devices. These devices usually have a master alarm output (visual and/or audible) that you can tie to a single Lamp, labelled 'ENGINE' or something similar. This lamp would then call your attention to the engine monitor which should be displaying the out-of-limit field. On my aircraft, I or-tie the engine monitor alarm output with a low oil pressure switch. This 'master' alarm serves three primary functions: Alarms from the engine monitor; fail-safe low oil pressure alarm (engine monitor not operating), and a master switch 'on' alarm. Vern Little RV-9A Dave Morris "BigD" wrote: >--> AeroElectric-List message posted by: "Dave Morris \"BigD\"" > >That's very cool! But, as I was designing my annunciator system, I found a >need for not only active high and active low, but also a threshold type >trigger where you can set a voltage comparator to trigger at a certain >voltage level. That would allow you to build both LV and HV annunciators >for the bus, as well as monitoring a number of other sensors without a lot >of external circuitry, for example carb ice, fuel tank level, AOA sensor, >and so on. > >Regards, > >Dave Morris > > >At 09:29 AM 9/11/2005, you wrote: > > >>--> AeroElectric-List message posted by: rv-9a-online >> >>A few months ago, several list browsers were discussing sources for LED >>annuciator lamps. >> >>I did a lot of research, and I wasn't happy with what was commercially >>available so I designed a family of lamp panels, available now through >>Vx Aviation http://www3.telus.net/aviation/vx.html >> >>Also, the free aircraft electrical system schematic on the site has been >>updated. Dynon contacted me with a warning not to use the switched >>power output from the D10A as an emergency power source for the >>E-MAG/P-MAG ignition. The design has been updated to reflect this change. >> >>Thanks, >> >>Vern Little >>RV-9A >> >> >> >> > > > > ________________________________ Message 8 _____________________________________ Time: 08:01:46 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Parts to build the OV protector --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:08 PM 9/11/2005 -0400, you wrote: >--> AeroElectric-List message posted by: "Rodney Dunham" > > >Brad, > >Why would you even consider building you own OV crowbar module??? > >B&C Specialties has one for just $35! > >I installed one in my OBAM and glad I did. No creative electrical >engineering for me. > >Rodney It depends on your goals. It's true that one can almost never assemble a product from scratch for less than it costs assembled. But one learns nothing about the processes, techniques and materials until you put your hands on them. Education is ALWAYS expensive in terms of time . . . and when purchasing parts for one instead off 100, they're more expensive too. The difference is that the folks who have done it are (by their own choice) more of a subject matter expert than those who have not. That's the major difference between myself and most of my contemporaries in the certified aviation industry. I've made it a career goal to put my hands on lots of different technologies, techniques and materials. It's been expensive but fun and it's now producing a return on investment. Bob . . . ________________________________ Message 9 _____________________________________ Time: 08:11:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Noise Filter for 5 lead motor --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 02:26 PM 9/8/2005 +0000, you wrote: >--> AeroElectric-List message posted by: revenson@comcast.net > >Yes, I have run this fan motor, but only from the battery (engine not >running): > >Low, medium, and high fan speeds work just fine, but when switching past >low,the supercharger high manifold pressure light comes on and stays on.To >get it off, I have to pull the 9pin dsub off the supercharger controller. >Once reconnected,as soon as I start moving that heater switch past the low >position, on comes thelight.My supercharger controller power is taken from >the line side of abreaker comingfrom the Auxbattery, while the heater >power is coming off the other side (the load side)of the same breaker. > >I've since removed the fan power and its 3 speed control wires well >away from the supercharger controller wires, as well as moved the >fan power source off the breaker near the supercharger controller source, >but I get the same response. > >Does this mean it's RFI coming from the fan motor (the motor case is plastic, >not metal)? > >And is this a candidate for an inductor/capacitor filter near the motor? My friend, you're now confronted with the classic chicken/egg conundrum in electromagnetic compatibility issues. (1) is the supercharger controller SPECIFIED to operate in any defined/known levels of abnormal stimulus? It appears to be an extraordinarily susceptible system. The fact that it wanders off into the weeds and locks up is particularly significant. If it just hiccupped and then went on about its business, we could feel more comfortable with a simple mitigation of stimulus by filtering at the antagonist, breaking propagation mode(s) or mitigation by filtering at the victim. My sense is that even if you FIXED the present problem with the fan, the system seems likely to be a high-risk victim for other noise sources. Given that your engine operation depends on reliable function of this product, I think it would be a good idea to have some discussion with the manufacturer. Do you have a wiring diagram for the controller you could scan and send to me? I think my initial approach to the problem would be to add protection AT the victim. Bob . . . ________________________________ Message 10 ____________________________________ Time: 08:45:12 AM PST US Subject: AeroElectric-List: Bringing alternator on line after engine start. From: "Rogers, Bob J." --> AeroElectric-List message posted by: "Rogers, Bob J." I am building a Mustang II kit plane with a Mazda Rotary 13B engine for power. The stock alternator is a 60 amp internally regulated Mitsubishi, which will be my primary source of electrical power. In addition to the stock alternator, I also have a John Deere 35 amp permanent magnet (PM) alternator for a backup. The electrical system is designed to receive power from either alternator, but not both at the same time. I want to be able to check that both alternators are working before take-off, which requires that I switch the electrical feed from one alternator to the other while the engine is running. The switch would be through a contactor for each alternator, which connects/disconnects the B terminal, as well as the electrical feed to the L & R terminals (which activate the alternator). I have followed the past discussions about how it is not a good idea to take an internally regulated alternator off-line after it is producing electricity. But, my Mazda service manual has a warning that I should not start the engine with the L & R terminals disconnected (these are the terminals that are used to activate the alternator). My plan was to start the engine with the backup PM alternator activated, check that it was working, and then switch to the main 60 amp alternator and leave it on. I would not go back to the PM alternator unless my primary alternator failed. My confusion is with the warning in the service manual that I should not start the engine unless the (main) alternator is already on line. I do not know the purpose for the warning and I do not comprehend the possible consequences of waiting to bring the primary alternator on line. If I start the engine with the back-up PM alternator on line and later switch to the primary (stock) alternator, which is my plan, I will be violating the warning in the service manual, because until I switch to the main alternator after the engine is running, the L & R terminals for the main alternator will, in effect, be disconnected. Can Bob Nuckolls or anyone else give me some advice on the correct procedure and sequence for checking that each alternator is functioning prior to take-off, without doing any harm to my electrical system? Also, I would like to hear your speculation on why the Mazda service manual has the warning discussed above. ________________________________ Message 11 ____________________________________ Time: 09:22:41 AM PST US From: revenson@comcast.net Subject: Re: AeroElectric-List: Re: Noise Filter for 4 lead motor --> AeroElectric-List message posted by: revenson@comcast.net (By the way, I characterized this wrong initially--there are 4 leads coming from the fan, not 5---ground, high, medium, and low speed). Here are my results so far: Battery condition was fine. Ground wire integrity was fine. Fan motor wires were rerouted. Problem still existed. Moved fan wires a foot or so away from the plane. Still light came on. Was able to fix it at the 'victim' two ways: Took the controller box off the aluminum subpanel where it was grounded locally with its mounting screws (in addition to the controller's ground wire). Just holding it up (insulating it from the airframe) resulted in no more light. So perhaps this was a ground loop issue. Secondly, I was in Radio Shack and happened to see part #273-105, a snap-on Ferrite Data-Line Filter ($5). This clamped nicely over the controller wires right at the dsub connector. This also independently solved the effects of the problem. I don't have a wiring diagram, but the supercharger manufacturer has been great. He's sending me a new chip that will eliminate the 'lock on' of the light. It will still be susceptible to voltage fluctuations, but at least it will reset and return to service. Still want to fix the antagonist. Took the fan motor out of the plane and my EAA tech counselor hooked it to an oscilloscope. It was quite noisy--the spikes were approx. 4-5 volts. These spikes didn't show up with a voltmeter. Placing a .01 micro farad ceramic, non-polarized capacitor across the main motor lead (hi speed) and the ground right at the motor showed very substantial noise reduction. Spikes went from several volts to 100-200 micro volts. Have not yet reinstalled the motor to verify, but I'm pretty sure this will fix this problem, and hopefully prevent other potential noise problems from this source. Roger. > > My friend, you're now confronted with the classic chicken/egg > conundrum in electromagnetic compatibility issues. > > (1) is the supercharger controller SPECIFIED to operate in > any defined/known levels of abnormal stimulus? It appears > to be an extraordinarily susceptible system. The fact that > it wanders off into the weeds and locks up is particularly > significant. If it just hiccupped and then went on about its > business, we could feel more comfortable with a simple mitigation > of stimulus by filtering at the antagonist, breaking propagation > mode(s) or mitigation by filtering at the victim. > > My sense is that even if you FIXED the present problem with > the fan, the system seems likely to be a high-risk victim > for other noise sources. Given that your engine operation > depends on reliable function of this product, I think it > would be a good idea to have some discussion with the > manufacturer. Do you have a wiring diagram for the controller > you could scan and send to me? I think my initial approach > to the problem would be to add protection AT the victim. > > Bob . . . > (By the way, I characterized this wrong initially--there are 4 leads coming from the fan, not 5---ground, high, medium, and low speed). Here are my resultsso far: Battery condition was fine. Ground wire integrity was fine. Fan motor wires were rerouted.Problem still existed. Moved fan wires a foot or so away from the plane. Still light came on. Was able to fix it at the 'victim' two ways: Took thecontroller box off thealuminum subpanel where it was grounded locally with its mounting screws (in addition to the controller's ground wire).Just holding it up (insulating it from the airframe)resulted in no more light. So perhaps this was a ground loop issue. Secondly, I was in Radio Shack and happened to see part #273-105, a snap-on Ferrite Data-Line Filter ($5). This clamped nicely over the controller wires right at the dsub connector. This also independently solved the effects of the problem. I don't have a wiring diagram, butthe supercharger manufacturer has been great.He's sending me a new chip that will eliminate the 'lock on' of the light.It will still be susceptible to voltage fluctuations, but at least it will reset and return to service. Still want to fixthe antagonist.Took the fan motorout of the plane and my EAA tech counselorhooked it to an oscilloscope. It was quite noisy--the spikes were approx. 4-5 volts. These spikes didn't show up with a voltmeter. Placing a .01 micro farad ceramic, non-polarized capacitor across the main motor lead (hi speed) and the ground right at the motor showed very substantial noise reduction. Spikes went from several volts to 100-200 micro volts. Have notyetreinstalled the motor to verify, but I'm pretty sure this will fix thisproblem, andhopefully preventother potentialnoise problems fromthissource. Roger. My friend, you're now confronted with the classic chicken/egg conundrum in electromagnetic compatibility issues. (1) is the supercharger controller SPECIFIED to operate in any defined/known levels of abnormal stimulus? It appears to be an extraordinarily susceptible system. The fact that it wanders off into the weeds and locks up is particularly significant. If it just hiccupped and then went on about its business, we could feel more comfortable with a simple mitigation of stimulus by filtering at the antagonist, breaking propagation mode(s) or mitigation by filtering at the victim. My sense is that even if you FIXED the present problem with the fan, the system seems likely to be a high-risk victim for other noise sources. Given that your engine operation depends on reliable function of this product, I think it woul d be a good idea to have some discussion with the manufacturer. Do you have a wiring diagram for the controller you could scan and send to me? I think my initial approach to the problem would be to add protection AT the victim. Bob . . . ________________________________ Message 12 ____________________________________ Time: 11:57:06 AM PST US From: "Dave & Brenda Emond" Subject: Re: AeroElectric-List: Re: RV 10 wiring architecture --> AeroElectric-List message posted by: "Dave & Brenda Emond" Fellow members Thanks for the replies, I will attempt to elaborate further, and appreciate your points of view. I have gone the QB route. I have just started the Fuse and hence the realisation that I need to start giving wiring and avionics some serious thought. I belong to chapter 645 which is based in Durban, South Africa. There are a couple of RV's being built at present. I do follow the matronics lists, and appreciate the the openess and spirit in which topics are discussed and information shared. I visited Oshkosh this year and got to meet some RV owners and builders. I bought a copy of the AeroElectric Connection and learnt much from it. Remembering I started from scratch, not difficult to double what I know about electrics, did that in the first paragraph. lol I am not IFR rated, so would put a VFR panel in to start with, I would like to fly night VFR, and then as future funding allows start looking towards upgrading to an IFR panel, and getting IFR rated. Hence I would like to start considering how to best configure the wiring side of my RV10 to accomodate easy upgrade going forward. Mission of my RV10 will be cross country. The LASAR ignition appealed to me because I know of two other local aircraft, using it. It has been reliable, and gives me confidence that lack of electrical power, doesn't equal engine shut down. I will take Bobs advice and read chapter 17, hopefully 1battery or two batteries. 1 alternator or two alternators. Will become more apparant. Dave Emond RV 10 #40159 > > Start with chapter 17 which speaks to system reliability > and system tailoring to the builder's mission and capabilities > of the airplane. > > If "going stock" with a clone of systems found on certified > ships is of interest, you can get real close with a minimum > of effort/risk by installing the system recommended by Van's. > > If you want something different, then Chapter 17 is a good > place to start. Without knowing more than you've told us so > far, it's difficult to advise now but consider a Figure > Z-11 architecture (See: > > http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf > > with an eye of upgrading to Figure Z-13/8 later. > > Are you hard over on the LASAR system? You can do as > well for a lot less money, installation time, weight > and probably better reliability with owner build and > maintained (OBAM) aircraft alternatives. Lightspeed > has a track record of over 15 years in the industry. > E-Mag (emagair.com) are the up-and-commers who show > a great deal of promise. > > What ever you do, put of buying any major electronics, > or even batteries until as late in your project as > possible. > > Welcome to the AeroElectric-List. Help us out by > telling us more about how you want to use this airplane. > > > Bob . . . > > > ________________________________ Message 13 ____________________________________ Time: 12:24:00 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List: Crowbar CB "problem" question --> AeroElectric-List message posted by: "Paul Messinger" Bob, as one of the "rumor mongers" I think you may have misunderstood my comments (or my intent at least). I never stated that damage was certain (or even likely). My point was, and is, that manufacturers clearly state that operation outside specified ranges MAY result in operation that is out of specification (this means some damage MAY occur, or the trip time or trip current may change or even failure to trip at all, just burn open). This is listed in the manufacturers specification for the device. Its never a good design practice to design a circuit that allows out of specification operation, and in this case, its so simple to prevent with the simple addition of a commonly available resistor that has no noticeable effect on the intended purpose of the circuit and prevents out of specification operation. Its simply not reasonable to assume that any 5 amp CB can be used and never damaged. No specific make and model CB has been specified so its reasonable to assume that any CB with the proper rating can be used and some sold by Aircraft Spruce etc have documented maximum ratings much lower than the maximum potential current in this application. Many parts have the ability to withstand major overload with no apparent (or real) damage but assuming that as fact is never a good idea. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar CB "problem" question > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > >> >> > AeroElectric-List message previously posted by: Richard Riley >> > >> > >> > <> > particularly one of the B&C regulators - how often do the nuisance >> > trips occur? >> > >> > If we're worried about the nuisance trips degrading field CB's, would >> > it be a reasonable fix to replace those CBs at annual?>> > > > There are rumors suggesting that some breakers are severely > overtaxed by the crowbar event that forces them open when > using this particular technology for ov protection. > > I have researched this allegation extensively. I've produced > many documents to combine with my personal anecdotal experience > going back 25 years that will not support the allegation > for the types of circuit breakers commonly used in the > Spam Can and OBAM aircraft industries. The field breaker > on B&C's regulator test stand got replaced after about > ten years of testing running over 1000 regulators that > were deliberately tripped as part of the acceptance test > procedure. > > I can find no substantive concerns about breaker life > in this application. Real problems have been rare and addressed > as soon as individuals experiencing problems brought it to > our attention. If the rate of problem events with components > and systems on bizjets were as low as for the crowbar system, > I'd be out of a job. > > Bob . . . > > > ________________________________ Message 14 ____________________________________ Time: 01:39:56 PM PST US From: Subject: AeroElectric-List: Inexpensive source for heat shrink tubing for Kroy, KSun labers needed --> AeroElectric-List message posted by: Listers, imagesupply.com offers heat shrink tubing kits for various labeling machines (I'm most interested in Kroy & KSun units) for $29. Anyone know of a less expensive source? Charlie Kuss ________________________________ Message 15 ____________________________________ Time: 02:19:55 PM PST US Subject: AeroElectric-List: Dumb question time From: "Hinde, Frank George (Corvallis)" --> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" I have an electrically dependant airplane (Lycoming with electric fuel pumps only). I see from the Z figures that there is no fuseable link in the Batt buss feed from the battery, the wire is pretty thin and short 6" or less. In my case the feed wire will need to be about 1.5 feet and capable of supporting a load of about 16 amps max running. Considering the engine will make like a glider if this lead shorts to ground (it will be well protected!) what size of wire should I install and should I install an automotive fuse link...Working on the principle that a glider is better than a glider with a cockpit fire? Thanks Frank ________________________________ Message 16 ____________________________________ Time: 02:51:20 PM PST US From: Bob White KSun.labers.needed@roxy.matronics.com Subject: Re: AeroElectric-List: Inexpensive source for heat shrink tubing for Kroy, KSun labers needed --> AeroElectric-List message posted by: Bob White If you need any quantity at all, I would reccomend Merithan Products Corp. http://tinyurl.com/75qwx For example, They will make 500 1/8 in dia labels 1/2 inch long printed with whatever you want for $28.50. Thats less than the $29 cartridge and more than twice the length (250 in. vs 110 in.) It isn't clear from the web site, but they will let you print several different labels and still give you the quantity price break for the total. I'm not sure but you may have to order 500 each to avoid the setup fee. - And I didn't need to buy a $300 printer. use the 1/8 inch or larger shrink tubing if you can. They have a little trouble keeping the text aligned on the 3/32 stuff. Of course if you need the flexability of printing a few at a time, this won't help. Bob W. On Mon, 12 Sep 2005 16:35:41 -0400 wrote: > --> AeroElectric-List message posted by: > > Listers, > imagesupply.com offers heat shrink tubing kits for various labeling machines (I'm most interested in Kroy & KSun units) for $29. Anyone know of a less expensive source? > Charlie Kuss > > > > > > > > -- http://www.bob-white.com N93BD - Rotary Powered BD-4 (real soon) Prewired EC2 Cables - http://www.roblinphoto.com/shop/ ________________________________ Message 17 ____________________________________ Time: 03:05:53 PM PST US From: Jim Streit KSun.labers.needed@roxy.matronics.com Subject: Re: AeroElectric-List: Inexpensive source for heat shrink tubing for Kroy, KSun labers needed --> AeroElectric-List message posted by: Jim Streit * LRT GROUP, INC. ccmc.gif (1193 bytes) ccvisa.gif (1343 bytes)* *Toll Free: 1-877-729-5769* * General Prices Labeling * Vinyl Prices_ for STIKA's _ * * K-SUN TAPES & PRICES * * _Etchall_ K-Sun 2001/2010 LabelShop /or/ Kroy 750 Systems 1 *$379.00* Specialized Shrink Tube Labeling Kit Marking wires, cables, tubes, and conduit, using shrink tubes has never been easier or more economical. The LABELShop 2001XLST is the smallest, most portable shrink tube labeler on the market. 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Shrink tube material is durable and gives a professionally labeled appearance. *LABELShop 2001XLST Machine and Accessories* * LABELShop 2001XLST* Item # Description Price 2001XLST K-Sun LABELShop 2001XLST Shrink Tube and Industrial Labeling Machine Kit Includes: (2) shrink tube cartridges (205 STBY, 211 STBR), 6-"AA" batteries, owner's manual, and industrial yellow plastic carrying case and adapter 379.00 LSAD LABELShop 2001XL, XLST and XLB Adapter 39.95 LSCSS - Yellow Industrial, Yellow Plastic Carrying Case holds machine, adapter, tapes and manual 59.95 LSHG LABELShop 2001XLST Heat Gun 49.95 *LABELShop Tape (for models 2001XLB, 2001XLST, 2001XL) 1/4" x 26'* Item# Description Price 206BB LABELShop Tape Black on Blue 1/4" 16.95 206BC LABELShop Tape Black on Clear 1/4" 16.95 206BG LABELShop Tape Black on Green 1/4" 16.95 206BR LABELShop Tape Black on Red 1/4" 16.95 206BW LABELShop Tape Black on White 1/4" 16.95 206BY LABELShop Tape Black on Yellow 1/4" 16.95 206WB LABELShop Tape White on Black 1/4" 16.95 *LABELShop Tape (for models 2001XLB, 2001XLST, 2001XL) 3/8" x 26'* Item# Description Price 209BB K-SUN LABELShop Tape Black on Blue 3/8" 16.95 209BC K-SUN LABELShop Tape Black on Clear 3/8" 16.95 209BG K-SUN LABELShop Tape Black on Green 3/8" 16.95 209BR K-SUN LABELShop Tape Black on Red 3/8" 16.95 209BW K-SUN LABELShop Tape Black on White 3/8" 16.95 209BY K-SUN LABELShop Tape Black on Yellow 3/8" 16.95 209WB K-SUN LABELShop Tape White on Black 3/8" 16.95 *LABELShop Tape (for models 2001XLB, 2001XLST, 2001XL) 1/2" x 26'* Item# Description Price 212BB K-SUN LABELShop Tape Black on Blue 1/2" 16.95 212BC K-SUN LABELShop Tape Black on Clear 1/2" 16.95 212BG K-SUN LABELShop Tape Black on Green 1/2" 16.95 212BR K-SUN LABELShop Tape Black on Red 1/2" 16.95 212BW K-SUN LABELShop Tape Black on White 1/2" 16.95 212BY K-SUN LABELShop Tape Black on Yellow 1/2" 16.95 212WB K-SUN LABELShop Tape White on Black 1/2" 16.95 212WG K-SUN LABELShop Tape White on Green 1/2" 16.95 212WL K-SUN LABELShop Tape White on Blue 1/2" 16.95 212WO K-SUN LABELShop Tape White on Orange 1/2" 16.95 212WR K-SUN LABELShop Tape White on Red 1/2" 16.95 *LABELShop Tape (for models 2001XLB, 2001XLST, 2001XL) 3/4" x 26'* Item# Description Price 218BB K-SUN LABELShop Tape Black on Blue 3/4" 20.95 218BC K-SUN LABELShop Tape Black on Clear 3/4" 20.95 218BG K-SUN LABELShop Tape Black on Green 3/4" 20.95 218BO K-SUN LABELShop Tape Black on Orange 3/4" 20.95 218BP K-SUN LABELShop Tape Black on Pink 3/4" 20.95 218BR K-SUN LABELShop Tape Black on Red 3/4" 20.95 218BV K-SUN LABELShop Tape Black on Violet 3/4" 20.95 218BW K-SUN LABELShop Tape Black on White 3/4" 20.95 218BX K-SUN LABELShop Tape Black on Gray 3/4" 20.95 218BY K-SUN LABELShop Tape Black on Yellow 3/4" 20.95 218RC K-SUN LABELShop Tape Red on Clear 3/4" 20.95 218RW K-SUN LABELShop Tape Red on White 3/4" 20.95 218WB K-SUN LABELShop Tape White on Black 3/4" 20.95 218WC K-SUN LABELShop Tape White on Clear 3/4" 20.95 218WG K-SUN LABELShop Tape White on Vivid Green 3/4" 20.95 218WL K-SUN LABELShop 2001XL Tape White on Vivid Blue 3/4" 20.95 218WO K-SUN LABELShop Tape White on Vivid Orange 3/4" 20.95 218WR K-SUN LABELShop Tape White on Vivid Red 3/4" 20.95 218WX K-SUN LABELShop Tape White on Gray 3/4" 20.95 *LABELShop Fluorescent (for models 2001XLB, 2001XLST, 2001XL) 3/4" x 16'* Item# Description Price 218FG K-SUN LABELShop Black on Fluor. 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Anyone know of a less expensive source? >Charlie Kuss > > > > ________________________________ Message 18 ____________________________________ Time: 03:18:14 PM PST US Subject: Re: AeroElectric-List: Dumb question time From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" What kind of fuel delivery system does your airplane use? Is it aircraft or automotive derivative? Regards, Matt- > --> AeroElectric-List message posted by: "Hinde, Frank George > (Corvallis)" > > I have an electrically dependant airplane (Lycoming with electric fuel > pumps only). > > I see from the Z figures that there is no fuseable link in the Batt buss > feed from the battery, the wire is pretty thin and short 6" or less. > > In my case the feed wire will need to be about 1.5 feet and capable of > supporting a load of about 16 amps max running. > > Considering the engine will make like a glider if this lead shorts to > ground (it will be well protected!) what size of wire should I install > and should I install an automotive fuse link...Working on the principle > that a glider is better than a glider with a cockpit fire? > > Thanks > > Frank > > ________________________________ Message 19 ____________________________________ Time: 03:43:59 PM PST US From: "Bill and Marsha" Subject: AeroElectric-List: ARC R402A Marker Pin out --> AeroElectric-List message posted by: "Bill and Marsha" Can any one supply me with a sys.pinout for a R402A Marker? Thanks Bill S. ________________________________ Message 20 ____________________________________ Time: 05:08:09 PM PST US From: "William" Subject: AeroElectric-List: PM alternator on Mazda engine. --> AeroElectric-List message posted by: "William" Bob, Where are you locating the PM alternator? Bill Schertz KIS Cruiser # 4045 Mazda 13-B ----- Original Message ----- From: "Rogers, Bob J." Subject: AeroElectric-List: Bringing alternator on line after engine start. > --> AeroElectric-List message posted by: "Rogers, Bob J." > > > I am building a Mustang II kit plane with a Mazda Rotary 13B engine for > power. The stock alternator is a 60 amp internally regulated > Mitsubishi, which will be my primary source of electrical power. In > addition to the stock alternator, I also have a John Deere 35 amp > permanent magnet (PM) alternator for a backup. ________________________________ Message 21 ____________________________________ Time: 05:23:31 PM PST US From: Kevin Horton Subject: Re: AeroElectric-List: Crowbar CB "problem" question --> AeroElectric-List message posted by: Kevin Horton Paul, If you look at the whole aircraft industry worldwide, there are probably dozens (hundreds?) of events daily where CBs open due to overcurrent. I bet the vast majority of those CBs go back into service once the original problem is fixed. Yet, reports of problems caused by CBs that didn't open when should seem quite rare. Are you suggesting that CBs be considered one-time-use devices, to be replaced after any event that opens them, as we have no way of knowing what the current was? Under what conditions would you replace a CB, and under what conditions would you put it back in service? Kevin Horton On 12 Sep 2005, at 15:20, Paul Messinger wrote: > --> AeroElectric-List message posted by: "Paul Messinger" > > > Bob, as one of the "rumor mongers" I think you may have > misunderstood my > comments (or my intent at least). > > I never stated that damage was certain (or even likely). > > My point was, and is, that manufacturers clearly state that operation > outside specified ranges MAY result in operation that is out of > specification (this means some damage MAY occur, or the trip time > or trip > current may change or even failure to trip at all, just burn open). > This is > listed in the manufacturers specification for the device. > > Its never a good design practice to design a circuit that allows > out of > specification operation, and in this case, its so simple to prevent > with the > simple addition of a commonly available resistor that has no > noticeable > effect on the intended purpose of the circuit and prevents out of > specification operation. > > Its simply not reasonable to assume that any 5 amp CB can be used > and never > damaged. > > No specific make and model CB has been specified so its reasonable > to assume > that any CB with the proper rating can be used and some sold by > Aircraft > Spruce etc have documented maximum ratings much lower than the maximum > potential current in this application. > > Many parts have the ability to withstand major overload with no > apparent (or > real) damage but assuming that as fact is never a good idea. > > Paul > > ----- Original Message ----- > From: "Robert L. Nuckolls, III" > To: > Subject: Re: AeroElectric-List: Crowbar CB "problem" question > > >> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >> >> >> >> >>> >>> >>>> AeroElectric-List message previously posted by: Richard Riley >>>> >>>> >>>> <>>> particularly one of the B&C regulators - how often do the nuisance >>>> trips occur? >>>> >>>> If we're worried about the nuisance trips degrading field CB's, >>>> would >>>> it be a reasonable fix to replace those CBs at annual?>> >>>> >> >> >> There are rumors suggesting that some breakers are severely >> overtaxed by the crowbar event that forces them open when >> using this particular technology for ov protection. >> >> I have researched this allegation extensively. I've produced >> many documents to combine with my personal anecdotal experience >> going back 25 years that will not support the allegation >> for the types of circuit breakers commonly used in the >> Spam Can and OBAM aircraft industries. The field breaker >> on B&C's regulator test stand got replaced after about >> ten years of testing running over 1000 regulators that >> were deliberately tripped as part of the acceptance test >> procedure. >> >> I can find no substantive concerns about breaker life >> in this application. Real problems have been rare and addressed >> as soon as individuals experiencing problems brought it to >> our attention. If the rate of problem events with components >> and systems on bizjets were as low as for the crowbar system, >> I'd be out of a job. >> >> Bob . . . >> >> >> >> ________________________________ Message 22 ____________________________________ Time: 05:38:56 PM PST US From: D Wysong Subject: Re: AeroElectric-List: Crowbar CB "problem" question --> AeroElectric-List message posted by: D Wysong INCOMING!!!! ;-) do not archive ---- Kevin Horton wrote: > --> AeroElectric-List message posted by: Kevin Horton > > Paul, > > If you look at the whole aircraft industry worldwide, there are > probably dozens (hundreds?) of events daily where CBs open due to > overcurrent. I bet the vast majority of those CBs go back into > service once the original problem is fixed. Yet, reports of problems > caused by CBs that didn't open when should seem quite rare. > > Are you suggesting that CBs be considered one-time-use devices, to be > replaced after any event that opens them, as we have no way of > knowing what the current was? Under what conditions would you > replace a CB, and under what conditions would you put it back in > service? > > Kevin Horton > > > On 12 Sep 2005, at 15:20, Paul Messinger wrote: > > >>--> AeroElectric-List message posted by: "Paul Messinger" >> >> >>Bob, as one of the "rumor mongers" I think you may have >>misunderstood my >>comments (or my intent at least). >> >>I never stated that damage was certain (or even likely). >> >>My point was, and is, that manufacturers clearly state that operation >>outside specified ranges MAY result in operation that is out of >>specification (this means some damage MAY occur, or the trip time >>or trip >>current may change or even failure to trip at all, just burn open). >>This is >>listed in the manufacturers specification for the device. >> >>Its never a good design practice to design a circuit that allows >>out of >>specification operation, and in this case, its so simple to prevent >>with the >>simple addition of a commonly available resistor that has no >>noticeable >>effect on the intended purpose of the circuit and prevents out of >>specification operation. >> >>Its simply not reasonable to assume that any 5 amp CB can be used >>and never >>damaged. >> >>No specific make and model CB has been specified so its reasonable >>to assume >>that any CB with the proper rating can be used and some sold by >>Aircraft >>Spruce etc have documented maximum ratings much lower than the maximum >>potential current in this application. >> >>Many parts have the ability to withstand major overload with no >>apparent (or >>real) damage but assuming that as fact is never a good idea. >> >>Paul >> >>----- Original Message ----- >>From: "Robert L. Nuckolls, III" >>To: >>Subject: Re: AeroElectric-List: Crowbar CB "problem" question >> >> >> >>>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >>> >>> >>> >>> >>>> >>>>>AeroElectric-List message previously posted by: Richard Riley >>>>> >>>>> >>>>><>>>>particularly one of the B&C regulators - how often do the nuisance >>>>>trips occur? >>>>> >>>>>If we're worried about the nuisance trips degrading field CB's, >>>>>would >>>>>it be a reasonable fix to replace those CBs at annual?>> >>>>> >>> >>> There are rumors suggesting that some breakers are severely >>> overtaxed by the crowbar event that forces them open when >>> using this particular technology for ov protection. >>> >>> I have researched this allegation extensively. I've produced >>> many documents to combine with my personal anecdotal experience >>> going back 25 years that will not support the allegation >>> for the types of circuit breakers commonly used in the >>> Spam Can and OBAM aircraft industries. The field breaker >>> on B&C's regulator test stand got replaced after about >>> ten years of testing running over 1000 regulators that >>> were deliberately tripped as part of the acceptance test >>> procedure. >>> >>> I can find no substantive concerns about breaker life >>> in this application. Real problems have been rare and addressed >>> as soon as individuals experiencing problems brought it to >>> our attention. If the rate of problem events with components >>> and systems on bizjets were as low as for the crowbar system, >>> I'd be out of a job. >>> >>> Bob . . . >>> >>> >>> >>> > > > > > > > > ________________________________ Message 23 ____________________________________ Time: 06:02:01 PM PST US From: D Wysong Subject: Re: AeroElectric-List: Crowbar OVM schematic version? --> AeroElectric-List message posted by: D Wysong Bob - Thanks for the crowbar BOM/schematic update. I wish you'd include a chapter in the 'connection that explains how you find/make/conjure up "free" time (... and without your wife finding out about it)?! Since someone brought up the buy vs. build topic, what flavor of OVM is B&C selling these days? Is there a way to guarantee we'll receive a Rev C unit if ordered tomorrow? The reason I ask is that the installation instructions on B&C's site contain a VERY outdated schematic. It doesn't affect the installation, of course, but it made me wonder how well they kept up with mod's. Thanks again for your service! D ________________________________ Message 24 ____________________________________ Time: 07:54:43 PM PST US From: "Paul McAllister" Subject: AeroElectric-List: Power FET's --> AeroElectric-List message posted by: "Paul McAllister" Hi all, A little off topic, but I am searching for a source of power FET's. The device I am looking for needs to be in a TO-204AA (TO-3) case Vds > 50 volt N Channel All I seem to be able to find on Mouser and Digikey is stuff in a T0-220 case. Thanks, Paul do not archive ________________________________ Message 25 ____________________________________ Time: 08:15:25 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Power FET's --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:53 PM 9/12/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "Paul McAllister" > > >Hi all, > >A little off topic, but I am searching for a source of power FET's. The >device I am looking for needs to be in a TO-204AA (TO-3) case > > Vds > 50 volt > N Channel > >All I seem to be able to find on Mouser and Digikey is stuff in a T0-220 case. > >Thanks, Paul > >do not archive How many do you need? What voltage and current ratings? I might have some in my junk-box. Bob . . . ________________________________ Message 26 ____________________________________ Time: 08:18:16 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar OVM schematic version? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:01 PM 9/12/2005 -0500, you wrote: >--> AeroElectric-List message posted by: D Wysong > >Bob - > >Thanks for the crowbar BOM/schematic update. I wish you'd include a chapter >in the 'connection that explains how you find/make/conjure up "free" time >(... and without your wife finding out about it)?! > >Since someone brought up the buy vs. build topic, what flavor of OVM is B&C >selling these days? Is there a way to guarantee we'll receive a Rev C unit >if ordered tomorrow? It's the ORIGINAL design with appropriate updates. B&C did a lifetime buy of the MBS4992 when it went obsolete. >The reason I ask is that the installation instructions on B&C's site contain >a VERY outdated schematic. It doesn't affect the installation, of course, >but it made me wonder how well they kept up with mod's. The original version doesn't need the added 22uf cap. The latest version has a very low gate pull-down resistor to offset dv/dt effects at the SCR anode. This configuration has been sold now for a couple of years and I'm not hearing any unhappy feedback from them. Bob . . . ________________________________ Message 27 ____________________________________ Time: 08:31:30 PM PST US From: D Wysong Subject: Re: AeroElectric-List: Power FET's --> AeroElectric-List message posted by: D Wysong Paul, give Newark a try (www.newark.com ). They have an Int'l Rectifier part that might meet your needs (IRF130). D do not archive ----------------------- > I am searching for a source of power FET's. The device I am looking > for needs to be in a TO-204AA (TO-3) case > > Vds > 50 volt > N Channel >