---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 09/16/05: 20 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:03 AM - Re: Re: Breaker Interrupt Rating (LarryRobertHelming) 2. 06:21 AM - Re: Re: Breaker Interrupt Rating (Robert L. Nuckolls, III) 3. 06:21 AM - Re: Re: Breaker Interrupt Rating (Robert L. Nuckolls, III) 4. 06:49 AM - Re: Re: Breaker Interrupt Rating (RV Builder (Michael Sausen)) 5. 07:25 AM - Re: degaussing (demagnetizing) my roll bar (Eric M. Jones) 6. 07:42 AM - Re: Breaker Interrupt Rating (Eric M. Jones) 7. 08:17 AM - Re: Breaker Interrupt Rating (Ernest Christley) 8. 08:52 AM - Re: Tire valve extension (Wayne Berg) 9. 09:41 AM - Re: Re: Breaker Interrupt Rating (Terry Watson) 10. 10:01 AM - Re: Re: degaussing (demagnetizing) (GMC) 11. 10:35 AM - Re: Breaker Interrupt Rating (Eric M. Jones) 12. 11:12 AM - Re: Re: Breaker Interrupt Rating (Mickey Coggins) 13. 11:16 AM - Re: Re: degaussing (demagnetizing) my roll bar (Mickey Coggins) 14. 12:27 PM - Re: degaussing (demagnetizing) my roll bar (Eric M. Jones) 15. 02:46 PM - magneto timing buzz box (Dan Checkoway) 16. 04:02 PM - Re: magneto timing buzz box (Robert L. Nuckolls, III) 17. 04:15 PM - Re: magneto timing buzz box (D Wysong) 18. 08:41 PM - Re: Re: Breaker Interrupt Rating (Charlie England) 19. 09:02 PM - Re: magneto timing buzz box (John Schroeder) 20. 09:54 PM - Re: Breaker Interrupt Rating (Eric M. Jones) ________________________________ Message 1 _____________________________________ Time: 05:03:41 AM PST US From: "LarryRobertHelming" Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "LarryRobertHelming" Bob: might I suggest you should use, for these that make claims and fail to back them up with their own testing as you have requested time and time again without response, the DELETE key. In other words just ignore them. Or better still, let them run their own bulletin board and ban them from posting on aeroelectric. They are obviously wanting to introduce and sell new products but should not need to throw insults and challenges without supporting scientific data to back it up. I have bought some stuff in the past when I thought I could see the merit. ( I bought Eric's Diode because it saves some current and my 35 amp alternator is stretched when landing with landing lights and strobes on while at low rpms. ) do not archive Indiana Larry, RV7 Tip Up SunSeeker -- wired without Transorbs or an avionic's buss and it has not self destructed after 61 hours. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ " Happiness: like a butterfly, when pursued, is always beyond our grasp, but which, if one sits quietly, may light upon you." Nathaniel Hawthorne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ----- Original Message ----- snip > Years later, some have decided to play the specs game when > in fact, they were blatantly guilty of mis-interpreting and/or > ignoring component specs just as I've been accused of doing. See: > > http://aeroelectric.com/articles/spike.pdf > > Some numbers tossed around in this thread weren't as wild as the > 700A fault currents claimed at the beginning of the latest > discussion started but were no more accurate. > > You guys are very long on throwing interpretation of specs around > and short on both hard data and experience. Please, sell all the > series shut down devices you wish . . . shucks, if you want > to peddle ov RELAYS . . . those are fine too. But if the only > way you can sell your products/ideas is to claim my products/ > ideas are deficient and use concocted numbers and claims to > support it, it's a sad day for the CONSUMERS of devices who > must make decisions on data no better than that offered by a > commercial for laundry soap. > > The challenge still stands. Take any breaker you like and > throw it across a 12v battery as many times as you like and > tell me how many times you have to whack it to trash it. > I've not been able to do it on my bench, maybe your's is > uglier than mine. I've done all the testing I'm going > to do to defend myself against the indefensible . . . the > interminable string of allegations. It's time for you guys > to put up or shut up. Show me the smoke . . . > > By the way Eric. I've been trying to identify a connector/tool > combination that works well with that sample of coax I got > from you in Plymouth. It may be great coax but I found it > very user-unfriendly to work with. If you're going to recommend > and/or sell it, I'll suggest you recommend/supply tools and > connectors to mate with it. A step-by-step instruction sheet > to aid the builder in getting it right by the second or third > try would be good too . . . > > Bob . . . ________________________________ Message 2 _____________________________________ Time: 06:21:13 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:02 AM 9/16/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "LarryRobertHelming" > > >Bob: might I suggest you should use, for these that make claims and fail to >back them up with their own testing as you have requested time and time >again without response, the DELETE key. It would be the EASIEST thing to do . . . But I cannot ignore echoes of some words by an intellectual super-hero of mine who once offered: "Perhaps the sentiments contained in the following pages, are not yet sufficiently fashionable to procure them general favor; a long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defence of custom. But the tumult soon subsides. Time makes more converts than reason." Common Sense by Thomas Paine 1776 The topic of his missive was to discuss the simple ideas of good government and the rights of individuals to live without fear of force or fraud against person or property (liberty for short). But the paragraph is a simple-idea unto itself. If you do not consistently and calmly defend a simple-idea by which you operate, then after a time a LACK OF DEFENSE is easily misconstrued to be a demonstration of weakness or falsity of the idea. Many folks in both government and science depend on the age old idea of simply wearing the opposition down with tenacity and the ease with which allegations can be tossed . . . one can conduct an effective offense even without UNDERSTANDING of the ideas under discussion! I heartily encourage folks who find these conversations troubling, boring, or useless to use the DELETE key as their personal feelings dictate. But if I'm to stay true to my craft, I cannot allow time to elevate bad science to the level of believable simply because I'm weary of defending good science. Nor do I belive it's a good idea to "take the discussions off-list" . . . our system of justice used to be founded on a judgement by our peers. One can acquire neither justice as an individual nor effect the propagation of good science by conducing the discussions in the dark. Thank you for your concerns my friend but as long as I can muster the energy, I'm not the one who is in need of rescue. Bob . . . ________________________________ Message 3 _____________________________________ Time: 06:21:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:49 AM 9/16/2005 +0200, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > > > By the way Eric. I've been trying to identify a connector/tool > > combination that works well with that sample of coax I got > > from you in Plymouth. It may be great coax but I found it > > very user-unfriendly to work with. If you're going to recommend > > and/or sell it, I'll suggest you recommend/supply tools and > > connectors to mate with it. A step-by-step instruction sheet > > to aid the builder in getting it right by the second or third > > try would be good too . . . > >I used this wire too. Since it was the first time I've ever >done anything with coax, I just thought working with coax was >hard. Now I feel a bit better! I got the stuff cut, trimmed, >and crimped, but I don't have 100% confidence in the quality >of my work. I was planning on finding out how good it works >on the first flight. What tool and connectors did you use? This coax is smaller than RG400/142 and larger than RG174. I have connectors that mate nicely with both sizes and neither was suited to this task. There might be an intermediate sized connector available but they're not in common distribution by any of my favorite suppliers. Bob . . . ________________________________ Message 4 _____________________________________ Time: 06:49:11 AM PST US Subject: RE: AeroElectric-List: RE: Breaker Interrupt Rating From: "RV Builder (Michael Sausen)" --> AeroElectric-List message posted by: "RV Builder (Michael Sausen)" Bob: might I suggest you should use, for these that make claims and fail to back them up with their own testing as you have requested time and time again without response, the DELETE key. In other words just ignore them. No kidding Or better still, let them run their own bulletin board and ban them from posting on aeroelectric. Umm, I believe this is Matt's list, not Bob's. Not trying to split hairs but this is a public forum and people should be allowed to disagree. I've said it before, I respect Bob and feel he adds more to the aviation community than 95% of the rest of us but I do still like to hear what other people have to say. If they don't have data to back it up I like to think I'm intelligent enough to take that into account when evaluating options. I have, on a regular basis, eschewed technologies which show much greater benefits in favor of proven technologies. Of course this list does ware the name of Bob's book and therefore we should expect him to defend his theories and methods with vigor. ;-) Let's not turn this into another pi$$ing contest on who's correct or who's technology is better. Just because something is new and/or unproven doesn't make it wrong just like old/proven technology doesn't automatically need to be replaced with the next new thing comes along. Use your own judgment. Michael Sausen -10 #352 Do not archive FWIW My 2 cents YMMV IMHO Yada yada yada ________________________________ Message 5 _____________________________________ Time: 07:25:16 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Re: degaussing (demagnetizing) my roll bar --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: Mickey Coggins >I'm not really sure how it got magnetized, but it came this >way from Van's. Seems to be a common problem. I checked it >by putting a simple orienteering compass near it. It swings >the needle when about a foot away. My panel mounted compass >will be less than a foot away. Thanks for the hints. Best regards, Mickey Hi Mickey, If you take your compass and examine a can of beans from your pantry, you will find it is magnetized. Almost every piece of ferrous metal slowly drifts into the magnetic state of its environment. Using the 4130 metal airframe for a ground also causes problems, since currents through the metal cause magnetization. Some alloys are worse than others. Aircraft tubing is almost all 4130 so choosing another alloy is not practical. Eliminating magnetization is a process of scrambling the domains by alternating the magnetic field while slowly reducing the field to zero. A spool of wire, and a variable output transformer (variac) are the tools you need; but how much and where is your individual experiment. > Is your fuselage located such that the roll bar is close to (underneath) > fluorescent lights. My roll bar & other parts became magnetized sitting > under a four tube fluorescent light fixture in garage. Magnetism bled > off after aircraft was moved to hangar. > > George in Langley BC George, I think it is more likely that moving the aircraft 90 degrees was the solution. But just wait a few months to see what happened. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "Nothing is too wonderful to be true." James Clerk Maxwell, discoverer of electromagnetism "Too much of a good thing can be wonderful." Mae West, discoverer of personal magnetism ________________________________ Message 6 _____________________________________ Time: 07:42:48 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: "Matt Prather" Matt-- > You might say that calibration and operating performance applies to the > behavior during only one firey interrupt. However, the calibration curve > only goes to 1000x the rating. Please look again. That's 10X the rating or 1000%. Bob claims the curves can be extended. This is a fundamental disagreement. Another problem is how the device will operate at 12V when the trip times are for 28V. There is an important alloy difference in contacts good for 12 and 28 volts. I don't know, but I can imagine a scenario where the contacts would weld without sufficient heat to cause the bimetal strip to flex enough. At any rate, it is wrong to think a device specified for 28V will "work fine" at 12-14V. It is also wrong to think that AC applications are more rigorous than DC. Paul Messinger's tests show that the discharge can be far greater than the CB is spec'd for. This devolved into an argument about battery resistances, but I believe Paul (since I am somewhat party to his testing). > Datasheets exist to cover the backsides of the producer, but also to > provide useful information about how to apply a product correctly. > If a breaker isn't reusable after a real-world hard fault, that's one of the industry's best-kept dirty little secrets. CBs fail all the time, but less so when they are properly located in real systems. In the worst case fault a CB only has to work three times to be approved for that current. "Crowbar" usage is a special application. There are plenty of guys using two motorcycle batteries in parallel, or newer batteries with phenomenal cranking capabilities. I believe Paul's 400 Amp result would be easy to get, and the CB is not correct for the application. Adding a resistor seems easy but requires a pulse rated part. You can't test the crowbar design into a good design. > None the less, maybe you're right, and Rutan is right. Minimum specs end up being performance ceilings. Agreed. But consider that in a mature product the performance tolerance is so small that it does not encourage improvement in the product. This is the best that can be done in a particular design. And it's a good thing, not a bad thing. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "Everything you've learned in school as "obvious" becomes less and less obvious as you begin to study the universe. For example, there are no solids in the universe. There's not even a suggestion of a solid. There are no absolute con- tinuums. There are no surfaces. There are no straight lines." - R. Buckminster Fuller ________________________________ Message 7 _____________________________________ Time: 08:17:21 AM PST US From: Ernest Christley Subject: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: Ernest Christley Eric M. Jones wrote: >Clever engineers those Klixon guys. Or maybe not.... Interrupting capacity >per UL1077/IEC934/EN60934 PC1 is defined as the maximum current that a >circuit breaker must interrupt-just one time-without causing a safely >hazard. KaaPowwwww......Operating a circuit breaker outside its published >ratings is a bad idea. Crowbarring cicuit breakers was an historic method >used in the olden days. Good thing that better methods like Linear >Non-crowbar OVP's were invented. Eric, it is my understanding, and the understanding of everyone I've ever dealt with, that the purpose of a circuit breaker is to break the circuit when something gets shorted. The only failure mode I've ever heard of is that the breaker trips easier as it gets old/wears out/is abused. In fact, when I worked as an electrician's helper in high school, the guy carried around an extra pair of old cutter for the express purpose of cutting through a pair of wires to cause the breaker to trip (so he'd know without a doubt that he was turning off the correct breaker to kill a circuit). That is, he would routinely throw a dead short to trip the breaker. I cannot fathom what 'safely hazard' can be caused by tripping a breaker. THAT IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a resettable circuit interrupton. The worst case scenario is that the breaker want stay closed if you ever hit it too hard. How long would D-Square stay in business if they advertised a breaker that "worked most of the time, but would sometimes fail with a dead short"? They would be laughed out of any industry that had anything to do with electricity. If the whole point is to open the circuit after something bad happens...and we're not going to reset it ('cause we have enough battery reserve to get where we were going, and we'll troubleshoot there), then what's wrong with it staying open after something bad happens? Could you please explain to the casual reader what these safety hazards are? Any example of it ever happening? Please, don't limit yourself to aviation applications. Any anectdotal example anywhere? -- ,|"|"|, | ----===<{{(oQo)}}>===---- Dyke Delta | o| d |o www.ernest.isa-geek.org | ________________________________ Message 8 _____________________________________ Time: 08:52:29 AM PST US From: "Wayne Berg" Subject: Re: AeroElectric-List: Tire valve extension --> AeroElectric-List message posted by: "Wayne Berg" Thanks Gary. Exactly what I wanted. Wayne Berg ----- Original Message ----- From: Gerry Holland Subject: Re: AeroElectric-List: Tire valve extension --> AeroElectric-List message posted by: Gerry Holland > --> AeroElectric-List message posted by: "Wayne Berg" > > Does anyone have a source for tire valve extentions that avoids having to > remove wheel pants to inflate tires? I know I've seen the add before but have > lost the flier. Try: http://www.aircraftextras.com/Valve-ext.htm I have one here in UK from them. Works great! Gerry Holland gholland@gemini-resourcing.com +44 7808 402404 (Mobile) +44 1249 700633 (Direct) +44 01225 436104 (Office) +44 870 7059985 (Fax) Gemini Resourcing Limited Hartham Park, Corsham, Wilts. SN13 0RP - UK Main: +44 1249 700630 Fax: +44 8707 051315 Website - http://www.gemini-resourcing.com DISCLAIMER: This message may contain privileged and confidential information. If you think for any reason this message has been addressed in error you must not copy or disseminate it and we would ask you to notify us immediately by return e-mail to info@gemini-resourcing.com. Internet emails are not necessarily secure. Gemini Resourcing Limited is registered in England with its address at: Hartham Park, Corsham, Wilts. SN13 0RP, England. Regards Gerry ________________________________ Message 9 _____________________________________ Time: 09:41:10 AM PST US From: "Terry Watson" Subject: RE: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "Terry Watson" I think this requires a little clarification. Anyone else who has been on the list from the beginning, including Bob, please correct me if I am wrong. Matt created the Aeroelectric list as a forum for Bob Nuckolls to field questions from experimental airplane builders or airplane owners, and as a general discussion list about aircraft electrical topics. Prior to having the Aeroelectric list, Bob was monitoring many lists and trying to answer questions on this subject. The list was in part an expression of Matt's appreciation for the exceptional value of Bob's efforts. Bob, as the true gentleman that he is, has never reminded anyone of that fact. So, yes, it is Matt's list, created as a forum for Bob. As I said, if I am wrong, please correct me. Terry RV-8A number 80729 Still finishing Seattle Umm, I believe this is Matt's list, not Bob's. Not trying to split hairs but this is a public forum and people should be allowed to disagree. I've said it before, I respect Bob and feel he adds more to the aviation community than 95% of the rest of us but I do still like to hear what other people have to say. If they don't have data to back it up I like to think I'm intelligent enough to take that into account when evaluating options. I have, on a regular basis, eschewed technologies which show much greater benefits in favor of proven technologies. Of course this list does ware the name of Bob's book and therefore we should expect him to defend his theories and methods with vigor. ;-) Let's not turn this into another pi$$ing contest on who's correct or who's technology is better. Just because something is new and/or unproven doesn't make it wrong just like old/proven technology doesn't automatically need to be replaced with the next new thing comes along. Use your own judgment. Michael Sausen -10 #352 Do not archive FWIW My 2 cents YMMV IMHO Yada yada yada ________________________________ Message 10 ____________________________________ Time: 10:01:34 AM PST US From: GMC Subject: Re: AeroElectric-List: Re: degaussing (demagnetizing) --> AeroElectric-List message posted by: GMC Hi Eric You could well be right. If anyone wants to check for magnetism in their workshop try checking with your hydro utility company they often have a meter [gausmeter ?] that you can borrow at no charge. I discovered that my fluorescent fixtures generated significant magnetic fields. George in Langley BC Eric M. Jones wrote: >--> AeroElectric-List message posted by: "Eric M. Jones" > >--> AeroElectric-List message posted by: Mickey Coggins > > > > >>I'm not really sure how it got magnetized, but it came this >>way from Van's. Seems to be a common problem. I checked it >>by putting a simple orienteering compass near it. It swings >>the needle when about a foot away. My panel mounted compass >>will be less than a foot away. Thanks for the hints. Best regards, Mickey >> >> > >Hi Mickey, > >If you take your compass and examine a can of beans from your pantry, you >will find it is magnetized. Almost every piece of ferrous metal slowly >drifts into the magnetic state of its environment. Using the 4130 metal >airframe for a ground also causes problems, since currents through the metal >cause magnetization. Some alloys are worse than others. Aircraft tubing is >almost all 4130 so choosing another alloy is not practical. > >Eliminating magnetization is a process of scrambling the domains by >alternating the magnetic field while slowly reducing the field to zero. A >spool of wire, and a variable output transformer (variac) are the tools you >need; but how much and where is your individual experiment. > > > >>Is your fuselage located such that the roll bar is close to (underneath) >>fluorescent lights. My roll bar & other parts became magnetized sitting >>under a four tube fluorescent light fixture in garage. Magnetism bled >>off after aircraft was moved to hangar. >> >>George in Langley BC >> >> > >George, > >I think it is more likely that moving the aircraft 90 degrees was the >solution. But just wait a few months to see what happened. > >Regards, >Eric M. Jones > > > ________________________________ Message 11 ____________________________________ Time: 10:35:34 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: Ernest Christley echristley@nc.rr.com Ernest, >Eric, it is my understanding, and the understanding of everyone I've ever >dealt >with, that the purpose of a circuit breaker is to break the circuit when >something >gets shorted. The only failure mode I've ever heard of is that the breaker >trips easier as it gets old/wears out/is abused. In fact, when I worked as >an electrician's helper in high school, the guy carried around an extra >pair >of old cutter for the express purpose of cutting through a pair of wires to >cause >the breaker to trip (so he'd know without a doubt that he was turning off >the correct breaker to kill a circuit). That is, he would routinely throw >a >dead short to trip the breaker. Cool! I met a very old electrician (everyone called him "Sparky"), who loved to regale the young engineers by telling them how he would use his bare fingers to determine the voltage...120, 240, and 480 VAC. >I cannot fathom what 'safely hazard' can be caused by tripping a breaker. >THAT >IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a >resettable >circuit interrupton. The worst case scenario is that the breaker want >stay closed if you ever hit it too hard. How long would D-Square stay in >business >if they advertised a breaker that "worked most of the time, but would >sometimes >fail with a dead short"? They would be laughed out of any industry that >had anything to do with electricity. >If the whole point is to open the circuit after something bad happens...and >we're >not going to reset it ('cause we have enough battery reserve to get where >we >were going, and we'll troubleshoot there), then what's wrong with it >staying >open after something bad happens? Could you please explain to the casual >reader >what these safety hazards are? Any example of it ever happening? Please, >don't limit yourself to aviation applications. Any anectdotal example >anywhere? Surely. If you Google ' Circuit Breaker Fail OR Failure' you will find the real world situation. My experience in using hundreds of thousands of circuit breakers or many types is that it is a far more complicated subject than most people believe. Safety hazards include not setting the local surroundings afire. I used to sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first test with a 24V battery as OV, the circuit breaker opened but failed catastrophically. Since the OVP test setup was not a perfect reflection of the real world, I discounted the incident, but later decided to not sell crowbar type OVPs at all. Paul Messinger's 400A measurement used a setup that was an exact duplicate (wire lengths and all) of his aircraft's system. In order for a CB to be rated as "interrupted without damage", it usually only has to do this 3X. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 Teamwork: " A lot of people doing exactly what I say." (Marketing exec., Citrix Corp.) ________________________________ Message 12 ____________________________________ Time: 11:12:20 AM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: Mickey Coggins >>> By the way Eric. I've been trying to identify a connector/tool >>> combination that works well with that sample of coax I got >>> from you in Plymouth. It may be great coax but I found it >>> very user-unfriendly to work with. If you're going to recommend >>> and/or sell it, I'll suggest you recommend/supply tools and >>> connectors to mate with it. A step-by-step instruction sheet >>> to aid the builder in getting it right by the second or third >>> try would be good too . . . >> >>I used this wire too. Since it was the first time I've ever >>done anything with coax, I just thought working with coax was >>hard. Now I feel a bit better! I got the stuff cut, trimmed, >>and crimped, but I don't have 100% confidence in the quality >>of my work. I was planning on finding out how good it works >>on the first flight. > > > What tool and connectors did you use? This coax is smaller > than RG400/142 and larger than RG174. I have connectors that > mate nicely with both sizes and neither was suited to this > task. There might be an intermediate sized connector available > but they're not in common distribution by any of my favorite > suppliers. I used one of these types of ratcheting crimpers: http://www.steinair.com/images/store/panels/sat001.jpg with this die: http://www.steinair.com/images/store/coaxdie.jpg I also used "standard" "RG400 & RG58" connectors: http://www.steinair.com/images/SA1010F.jpg I put heat shrink around the whole connector like this: http://www.rv8.ch/article.php?story=20050110191323706 I guess if Eric chimes in and comes up with some better hardware, I'll re-do the cables. Probably take about 20 minutes - everything's still open and easy to get to. -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________ Message 13 ____________________________________ Time: 11:16:32 AM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: Re: degaussing (demagnetizing) my roll bar --> AeroElectric-List message posted by: Mickey Coggins > Eliminating magnetization is a process of scrambling the domains by > alternating the magnetic field while slowly reducing the field to zero. A > spool of wire, and a variable output transformer (variac) are the tools you > need; but how much and where is your individual experiment. Hi Eric, Thanks for the info. Do you think it's a waste of time to do this? Thanks, Mickey -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________ Message 14 ____________________________________ Time: 12:27:13 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Re: degaussing (demagnetizing) my roll bar --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: Mickey Coggins > Eliminating magnetization is a process of scrambling the domains by > alternating the magnetic field while slowly reducing the field to zero. A > spool of wire, and a variable output transformer (variac) are the tools > you > need; but how much and where is your individual experiment. >Hi Eric, >Thanks for the info. Do you think it's a waste of time to do this? Thanks, >Mickey Mickey, If it were my airplane, I'd do it once or twice if the equipment was not too hard to find. (BTW--You do live in the world's HQ for demagnetizers. Every watchmaker has at least one.) Then depending on the results I'd either do it periodically; mu-metal wrap the rollbar near the compass; get a remote compass; or just live with it. Eric do not archive ________________________________ Message 15 ____________________________________ Time: 02:46:12 PM PST US From: "Dan Checkoway" Subject: AeroElectric-List: magneto timing buzz box --> AeroElectric-List message posted by: "Dan Checkoway" I've scoured the archives and haven't found anything definitive. I want to roll my own "buzz box" for timing my magneto. This can't be too complicated (although it's over my head, else I'd already have done it). Does anybody have a buzz box circuit that works? )_( Dan RV-7 N714D http://www.rvproject.com ________________________________ Message 16 ____________________________________ Time: 04:02:28 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: magneto timing buzz box --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 02:44 PM 9/16/2005 -0700, you wrote: >--> AeroElectric-List message posted by: "Dan Checkoway" > >I've scoured the archives and haven't found anything definitive. I want to >roll my own "buzz box" for timing my magneto. This can't be too complicated >(although it's over my head, else I'd already have done it). > >Does anybody have a buzz box circuit that works? I had a schematic for one (I think out of a Sport Aviation article) but I can't put my hands on it. The problem with using an ohmmeter to detect point opening arises from the fact that points in a mag are paralleled with a very low resistance primary winding on the magneto core. It looks like a dead short to most ohmmeters and therefore, difficult to detect when the points open. The "buzz box" used a buzzer to generate a relatively high frequency AC signal that could take advantage of the primary winding's apparent rise in resistance as the excitation frequency went up . . . much easier to tell when the dead-short points opened up. I'm wondering if a milliohmmeter adapter I showed at: http://aeroelectric.com/articles/LowOhmsAdapter_3.pdf wouldn't detect the points opening in a magneto . . . I'll keep an eye out for the article I copied and post it if I find it. Bob . . . ________________________________ Message 17 ____________________________________ Time: 04:15:25 PM PST US From: D Wysong Subject: Re: AeroElectric-List: magneto timing buzz box --> AeroElectric-List message posted by: D Wysong Is it this one, Bob? http://www.rst-engr.com/kitplanes/KP9910/KP9910.htm D -------------------------- Robert L. Nuckolls, III wrote: > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 02:44 PM 9/16/2005 -0700, you wrote: > > >>--> AeroElectric-List message posted by: "Dan Checkoway" >> >>I've scoured the archives and haven't found anything definitive. I want to >>roll my own "buzz box" for timing my magneto. This can't be too complicated >>(although it's over my head, else I'd already have done it). >> >>Does anybody have a buzz box circuit that works? > > > I had a schematic for one (I think out of a Sport Aviation > article) but I can't put my hands on it. The problem with using > an ohmmeter to detect point opening arises from the fact that > points in a mag are paralleled with a very low resistance > primary winding on the magneto core. It looks like a dead > short to most ohmmeters and therefore, difficult to detect when > the points open. The "buzz box" used a buzzer to generate > a relatively high frequency AC signal that could take advantage > of the primary winding's apparent rise in resistance as the > excitation frequency went up . . . much easier to tell when > the dead-short points opened up. > > I'm wondering if a milliohmmeter adapter I showed at: > > http://aeroelectric.com/articles/LowOhmsAdapter_3.pdf > > wouldn't detect the points opening in a magneto . . . > > I'll keep an eye out for the article I copied and post > it if I find it. > > Bob . . . > > > > > > > ________________________________ Message 18 ____________________________________ Time: 08:41:34 PM PST US From: Charlie England Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: Charlie England Eric M. Jones wrote: >--> AeroElectric-List message posted by: "Eric M. Jones" > >--> AeroElectric-List message posted by: Ernest Christley >echristley@nc.rr.com > >Ernest, > > > >>Eric, it is my understanding, and the understanding of everyone I've ever >>dealt >>with, that the purpose of a circuit breaker is to break the circuit when >>something >>gets shorted. The only failure mode I've ever heard of is that the breaker >>trips easier as it gets old/wears out/is abused. In fact, when I worked as >>an electrician's helper in high school, the guy carried around an extra >>pair >>of old cutter for the express purpose of cutting through a pair of wires to >>cause >>the breaker to trip (so he'd know without a doubt that he was turning off >>the correct breaker to kill a circuit). That is, he would routinely throw >>a >>dead short to trip the breaker. >> >> > >Cool! I met a very old electrician (everyone called him "Sparky"), who loved >to regale the young engineers by telling them how he would use his bare >fingers to determine the voltage...120, 240, and 480 VAC. > > > >>I cannot fathom what 'safely hazard' can be caused by tripping a breaker. >>THAT >>IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a >>resettable >>circuit interrupton. The worst case scenario is that the breaker want >>stay closed if you ever hit it too hard. How long would D-Square stay in >>business >>if they advertised a breaker that "worked most of the time, but would >>sometimes >>fail with a dead short"? They would be laughed out of any industry that >>had anything to do with electricity. >> >> > > > >>If the whole point is to open the circuit after something bad happens...and >>we're >>not going to reset it ('cause we have enough battery reserve to get where >>we >>were going, and we'll troubleshoot there), then what's wrong with it >>staying >>open after something bad happens? Could you please explain to the casual >>reader >>what these safety hazards are? Any example of it ever happening? Please, >>don't limit yourself to aviation applications. Any anectdotal example >>anywhere? >> >> > >Surely. > >If you Google ' Circuit Breaker Fail OR Failure' you will find the real >world situation. My experience in using hundreds of thousands of circuit >breakers or many types is that it is a far more complicated subject than >most people believe. > >Safety hazards include not setting the local surroundings afire. I used to >sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B >Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first >test with a 24V battery as OV, the circuit breaker opened but failed >catastrophically. Since the OVP test setup was not a perfect reflection of >the real world, I discounted the incident, but later decided to not sell >crowbar type OVPs at all. > >Paul Messinger's 400A measurement used a setup that was an exact duplicate >(wire lengths and all) of his aircraft's system. In order for a CB to be >rated as "interrupted without damage", it usually only has to do this 3X. > >Regards, >Eric M. Jones >www.PerihelionDesign.com >113 Brentwood Drive >Southbridge MA 01550-2705 >(508) 764-2072 > You have personal experience using hundreds of thousands of circuit breakers? You must have had an exceedingly long and/or prolific career. If we limit the count to 200,000, that works out to around 15 per work day over a 50 year career if you don't take any vacations. Were they all aircraft style c/b's? ;-) Charlie ________________________________ Message 19 ____________________________________ Time: 09:02:24 PM PST US Subject: Re: AeroElectric-List: magneto timing buzz box From: "John Schroeder" --> AeroElectric-List message posted by: "John Schroeder" Kitplanes had an article about this a couple of yerars ago. > > Does anybody have a buzz box circuit that works? > > )_( Dan > RV-7 N714D > http://www.rvproject.com ________________________________ Message 20 ____________________________________ Time: 09:54:28 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: RE: Breaker Interrupt Rating --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: Charlie England ceengland@bellsouth.net >You have personal experience using hundreds of thousands of circuit >breakers? You must have had an exceedingly long and/or prolific career. >If we limit the count to 200,000, that works out to around 15 per work >day over a 50 year career if you don't take any vacations. Were they all >aircraft style c/b's? ;-) Charlie, Sure. I was chief engineer for 28 years at a medical instrument company that made gizmos in boxes to be used in surgery, before that I ran my own similar company. The medical business preferred circuit breakers because finding a replacement fuse in the middle of an operation was risky business--so nearly everything we made had a circuit breaker in it. Some had more than one. Twenty different kinds probably. Obviously I didn't install many myself, but supervised what was happening and had to obtain a basketful of worldwide electrical approvals for most devices that used them. Let me tell you....Brazilian electricity is a nightmare. Aviation style c/b's...? Some were but most of ours were for 120/230VAC. Do Not Archive Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "The man who carries a cat by the tail learns something that can be learned in no other way." - Mark Twain