---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 02/04/24: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:29 AM - Re: toggle switches better than Carling? (Ken Ryan) 2. 09:16 AM - Re: toggle switches better than Carling? (Charlie England) 3. 09:54 AM - Re: toggle switches better than Carling? (Matthew S. Whiting) 4. 12:07 PM - Re: toggle switches better than Carling? (Robert L. Nuckolls, III) 5. 12:32 PM - Re: One for the battery gurus: recovery from deep discharge (Robert L. Nuckolls, III) 6. 02:45 PM - Re: toggle switches better than Carling? (N1921R) ________________________________ Message 1 _____________________________________ Time: 06:29:19 AM PST US From: Ken Ryan Subject: Re: AeroElectric-List: toggle switches better than Carling? Nikkai (NKK) switches seem good to me and they are available in fast on configuration. On Sat, Feb 3, 2024 at 3:58=AFPM N1921R wrot e: > > > After reading on VAF about failures of Carling toggle switches with fasto n > tabs attached with hollow rivets I was planning to use Honeywell TS but > they have been discontinued. > > One VAF thread: > https://vansairforce.net/threads/failing-intermittent-toggle-switch.17276 5/ > > I'd like to find good quality toggle switches that use faston tabs and > come in configurations like 2-10... any thoughts here on AEL? > > I find APEM on Newark, part number 644H/2 for instance seems to be 2-10 > configuration. It has tabs called solder lug/quick-connect which have a > larger thru hole compared to what APEM calls normalized quick-connect tab s > which have the smaller through hole I am used to seeing. APEMs with > normalized quick-connect tabs are not stocked that I can find. The switch > description says "terminal and contact support is manufactured from a > single piece of metal. The contacts are resistance-welded to the terminal > for increased mechanical strength". Bushing dia is 12 mm which is > practically the same, 0.004" larger, compared to the 15/32" I am used to. > > Newark page for APEM 644H/2: > https://www.newark.com/apem/644h-2/switch-dp3t-10a-250vac/dp/96C7308 > > APEM 600H data sheet: https://www.farnell.com/datasheets/1697794.pdf > > -------- > John Bright, RV-6A N1921R, working on FWF. > Single battery, alternator on main bus, Monkworkz generator on > engine/essential bus. > My links here > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=513195#513195 > > =========== =========== =========== =========== =========== > > ________________________________ Message 2 _____________________________________ Time: 09:16:12 AM PST US From: Charlie England Subject: Re: AeroElectric-List: toggle switches better than Carling? On Sat, Feb 3, 2024 at 6:58=AFPM N1921R wrot e: > > > After reading on VAF about failures of Carling toggle switches with fasto n > tabs attached with hollow rivets I was planning to use Honeywell TS but > they have been discontinued. > > One VAF thread: > https://vansairforce.net/threads/failing-intermittent-toggle-switch.17276 5/ > > I'd like to find good quality toggle switches that use faston tabs and > come in configurations like 2-10... any thoughts here on AEL? > > I find APEM on Newark, part number 644H/2 for instance seems to be 2-10 > configuration. It has tabs called solder lug/quick-connect which have a > larger thru hole compared to what APEM calls normalized quick-connect tab s > which have the smaller through hole I am used to seeing. APEMs with > normalized quick-connect tabs are not stocked that I can find. The switch > description says "terminal and contact support is manufactured from a > single piece of metal. The contacts are resistance-welded to the terminal > for increased mechanical strength". Bushing dia is 12 mm which is > practically the same, 0.004" larger, compared to the 15/32" I am used to. > > Newark page for APEM 644H/2: > https://www.newark.com/apem/644h-2/switch-dp3t-10a-250vac/dp/96C7308 > > APEM 600H data sheet: https://www.farnell.com/datasheets/1697794.pdf > > -------- > John Bright, RV-6A N1921R, working on FWF. > Single battery, alternator on main bus, Monkworkz generator on > engine/essential bus. > My links here > > > Hi John, Did you read the entirety of that VAF thread? Might be worth your time to go back and re-read it, assigning weight to what's significant. Your takeaway about hollow rivets might be the most insignificant thing in the thread. ;-) There are also some criticisms of supposed failure points where the responder got the failure point wrong. Only one responder mentioned multiple failures; that could have been a bad batch of switches, or 'pilot error'. Consider that quite a few of us have seen failures of milspec circuit breakers; does that mean *everyone* should find a different circuit breaker? (I was the 1st responder to that VAF thread.) Virus-free.www.avast.com <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> ________________________________ Message 3 _____________________________________ Time: 09:54:07 AM PST US From: "Matthew S. Whiting" Subject: Re: AeroElectric-List: toggle switches better than Carling? --- MIME Errors - No Plain-Text Section Found --- A message with no text/plain MIME section was received. The entire body of the message was removed. Please resend the email using Plain Text formatting. HOTMAIL is notorious for only including an HTML section in their client's default configuration. If you're using HOTMAIL, please see your email application's settings and switch to a default mail option that uses "Plain Text". --- MIME Errors No Plain-Text Section Found --- ________________________________ Message 4 _____________________________________ Time: 12:07:52 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: toggle switches better than Carling? At 11:15 AM 2/4/2024, you wrote: >On Sat, Feb 3, 2024 at 6:58=AFPM N1921R ><RV.6A.N1921R@gmail.com> wrote: >"N1921R" <RV.6A.N1921R@gmail.com> > >After reading on VAF about failures of Carling >toggle switches with faston tabs attached with >hollow rivets I was planning to use Honeywell TS >but they have been=C2 discontinued. > >One VAF thread: >https://vansairforce.net/threads/failing-intermittent-toggle-switch.172765 / > >I'd like to find good quality toggle switches >that use faston tabs and come in configurations >like 2-10... any thoughts here on AEL? Failed after 660 hrs??? How many years of service and under what manner of environmental/service stress? Was root cause for the failure skillfully diagnosed? I've studied and resolved dozens of 'contact failures' in a constellation of relays and switches that ranged from hardware-store to mil-spec devices. There were very few instances wherein studies were the basis for 'upgrading' a failed device. The Carling switch configuration under discussion has been used in very high volumes in aircraft for decades. We're just making the change-over to those switches (with rocker actuators) at Cessna when I worked there in 1965. Yes, there were field failures but relatively rare in the grand scheme of things with majority of failures attributable to conditions external to the switch . . . moisture, bad terminal crimp, poor fast-on-grip, etc. So what's the benchmark for satisfactory service life? Is the failure of any switch a potential for uncomfortable termination of flight? If so, what about the myriad of peripheral components of that system? Had a reader many moons ago who was worried about the quality of his landing light switch . . . I had to remind him, "You do know those bulbs burn out sometime." Do your FMEA and strive to have no single failure become a hazard to comfortable completion of flight. Did a study on roll trim relays on Beechjets way back when where contacts were sticking shut causing the occasional hard-over runaway in roll trim. After much study and bench tests I discovered a design consideration that didn't manifest until a redesign of the trim system replaced legacy 10A relays (mil-spec no less) with a 5A relay (also mil-spec). I discovered that arcing during contact bounce was exacerbated by reflections of energy from the far end of a shielded wire bypassed with a fat capacitor. Clip the shield ground or eliminate the capacitor (neither one of which was needed) and the problem resolved. During the investigation of some 2+ years, I did discover that one brand of relay was a bit more tolerant of the abuse. Management in their infinite wisdom purged stock of the 'bad' relay and banned them from future purchase. The 'good' relay was substituted and life went on . . . that way nobody had to change any drawings. Yeah, that's a short story made long but I hope it illustrates the value in having good data as to cause/effect and cost/benefit before changing course from a well worn pathway. Bob . . . //// (o o) ===========o00o=(_)=o00o======= = < Go ahead, make my day . . . > < show me where I'm wrong. > ======================== ======== In the interest of creative evolution of the-best-we-know-how-to-do based on physics and good practice. ________________________________ Message 5 _____________________________________ Time: 12:32:10 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: One for the battery gurus: recovery from deep discharge At 11:25 AM 2/3/2024, you wrote: >In my case I had a newish deep cycle=C2 12v100a/h >battery in an inverter drop to 3.6v...dont ask... > >Anyway...the Victron charger didnt see the >battery...put a 24v CTEK intelligent charger on >it got it to 15v in about 30min. Changed over to >the 7amp Victron 12v smart charger... > >I had just about given up after about 5 days >when suddenly the charge light went green! > >Its been about a month and the battery seems fine. Maybe a bit of luck? It may have been quite predictable. When the battery is discharge to LESS than zero, i.e. open terminal volts less than 12.0 V and SG below 1.12, then what's left of the acid is free do mischief on the battery's innards . . . like sulfation at an accelerated rate. In the fully charged state, the negative plate consists of lead; the positive plate is lead dioxide. The electrolyte has a higher concentration acid which is where chemical energy is stored. When discharged, both the positive and negative plates become lead sulfate; the electrolyte becomes less acid and more water. The lead sulfate is initially fine grains and convertible back into hydrogen sulfide thus increasing strength of the acid. Depending on depth and duration of discharge, SOME of the lead sulfate forms hard, insoluble crystals thus diminishing battery CAPACITY. Without a doubt, your battery has experienced and extra-ordinary, deep-discharge which will have consumed more of its service life than if it had been subjected to a normal discharge-recharge cycle. Bob . . . //// (o o) ===========o00o=(_)=o00o======= = < Go ahead, make my day . . . > < show me where I'm wrong. > ======================== ======== In the interest of creative evolution of the-best-we-know-how-to-do based on physics and good practice. ________________________________ Message 6 _____________________________________ Time: 02:45:53 PM PST US Subject: AeroElectric-List: Re: toggle switches better than Carling? From: "N1921R" Thanks guys for bringing me back to reality. -------- John Bright, RV-6A N1921R, working on FWF. Single battery, alternator on main bus, Monkworkz generator on engine/essential bus. 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