---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 04/26/13: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:38 AM - Re: Master / Starter Relay (Eric M. Jones) 2. 06:30 AM - Re: Re: Master / Starter Relay (Bill Bradburry) 3. 08:59 AM - Re: Re: Master / Starter Relay (Holger Selover-Stephan) 4. 09:37 AM - Re: Fw: Putting two batteries in parallel (Robert L. Nuckolls, III) 5. 09:39 AM - Re: Master / Starter Relay (Robert L. Nuckolls, III) 6. 09:41 AM - Re: Master / Starter Relay (Robert L. Nuckolls, III) 7. 09:53 AM - Re: Re: Master / Starter Relay (Ed Holyoke) 8. 11:44 AM - Re: 28V to 15.6V @ 5A (Jeff Page) ________________________________ Message 1 _____________________________________ Time: 05:38:43 AM PST US Subject: AeroElectric-List: Re: Master / Starter Relay From: "Eric M. Jones" > Very modern and expensive We use Tyco at work ..all good stuff ... but > what is wrong with $ 20,- from Vans? The $20 Type 70 contactor has been used for years. It might be okay for some applications, but there have been great strides in designing contactors. I often recommend the Kilovac EV200, the Gigavac GX-11, or NO CONTACTORS AT ALL (Use a remote battery switch from Flaming River) but there are many good choices. The Type 70 is rated at 122 degress F, is not sealed, not fuel proof, G-sensitive, requires external diodes (use Bidir Zeners!) and is less than ideal in other respects. But it is cheap. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=399419#399419 ________________________________ Message 2 _____________________________________ Time: 06:30:36 AM PST US From: "Bill Bradburry" Subject: RE: AeroElectric-List: Re: Master / Starter Relay And has been used with no real problem in aircraft for about a hundred years! If you glue dollar bills to the sides of the fuselage, it will make the fuselage a little stronger... :>) B2 -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric M. Jones Sent: Friday, April 26, 2013 8:37 AM Subject: AeroElectric-List: Re: Master / Starter Relay > Very modern and expensive We use Tyco at work ..all good stuff ... but > what is wrong with $ 20,- from Vans? The $20 Type 70 contactor has been used for years. It might be okay for some applications, but there have been great strides in designing contactors. I often recommend the Kilovac EV200, the Gigavac GX-11, or NO CONTACTORS AT ALL (Use a remote battery switch from Flaming River) but there are many good choices. The Type 70 is rated at 122 degress F, is not sealed, not fuel proof, G-sensitive, requires external diodes (use Bidir Zeners!) and is less than ideal in other respects. But it is cheap. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=399419#399419 ________________________________ Message 3 _____________________________________ Time: 08:59:23 AM PST US Subject: Re: AeroElectric-List: Re: Master / Starter Relay From: Holger Selover-Stephan On Apr 26, 2013, at 6:29 AM, Bill Bradburry wrote: > If you glue dollar bills to the sides of the fuselage, it will make the > fuselage a little stronger... :>) Interesting. From a structural standpoint, which bill is recommended: $1, $20, $50, ...? Probably the higher ones, you get what you pay for? Holger PS: Plugged my 40W LED landing light into the cigarette lighter on a flight the other day, and there was no RF noise. More tests needed. ________________________________ Message 4 _____________________________________ Time: 09:37:40 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Fwd: Putting two batteries in parallel >I,m very excited to have a book like yours to refer to when it comes >to electrical airplanes. I have a couple of questions that I hope >that you can clarify for me. Thank you, I'll try . . . > >First: I'm one of those that thought that two batteries in >parallel will drain the higher one until both are at equal voltages >(kinda like air pressure tanks). No. Batteries CHARGE at 13.5 and above. Batteries DELIVER at 12.5 and below. Hence, a battery cannot charge another battery of same voltage. > The question is, when one battery has a shorted cell, will the > other battery not drain through the shorted cells in the bad > battery? This problem was one of the possible causes for Mr. > Gomez. I do understand that this is rare. Is it an idea to use a > diode from each battery so they do not feed into each other? Or is > this not necessary. No, with a properly maintained battery . . . in particular an SVLA battery . . . shorted cells are so rare as to be insignificant in terms of system reliability studies. > >Second: As per Figure 17-4, would you have the regulator for the >SD-8 set lower than the main regulator so that it will not take all >the load if both alternators were switched on together? No, an SD-8 is not intended to run simultaneously with a larger alternator. The SD-8 is a stand-by alternator held in quiescent reserve until needed. >Third: You mentioned that alternators do not run well without a >battery. How possible is it to use an alternator by itself or with >a shorted battery? Could you use the aux alternator with this >back-up from TCW >Technologies: http://www.tcwtech.com/IBBS.htm If an alternator is up and running during a battery contactor failure . . . it will continue to power the airplane transparently to the pilot. There is risk that an alternator not supported by a battery can be 'stalled' with application of a large load transient . . . like landing gear pump motor. But unless your airplane's electro-whizzies are capable of producing such transients, the concern is insignificant. If you have dual, battery powered, electronic ignition and single alternator, a second battery will improve system reliability numbers. Figure Z-13/8 has about everything you'll ever need . . . but without the added cost of ownership for a second battery. Ignition products like P-Mags also eliminate any need for multiple batteries. In any case, factoring a 'shorted battery' into your Failure Mode Effects Analysis is not productive. Plan active notification of low volts, considered preventative maintenance of your battery and a Plan-B tailored to your system demands for continued flight to airport of intended destination. Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:39:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Master / Starter Relay At 04:14 PM 4/25/2013, you wrote: >Pengilly > >Does anyone have any thoughts on the suitability >of these devices from Tyco for our applications, >although may be a little expensive (70 = $110, >both + tax)? How are they supposed to be mounted? > >http://uk.farnell.com/te-connectivity/v23130c2021a412/relay-battery-disconnect-12v/dp/1770635 This is a BI-STABLE relay. Energize one coil to close it; energize the other coil to open it. This calls for a new paradigm in battery master switches. It's a fine product. My first question would explore expected return on investment for the purchase and installation of such a device. Bob . . . ________________________________ Message 6 _____________________________________ Time: 09:41:29 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Master / Starter Relay At 04:14 PM 4/25/2013, you wrote: >Pengilly > >Does anyone have any thoughts on the suitability >of these devices from Tyco for our applications, >although may be a little expensive (=A370 = $110, >both + tax)? How are they supposed to be mounted? > >http://uk.farnell.com/te-connectivity/v23130c2021a412/relay-battery-disconn ect-12v/dp/1770635 This is a BI-STABLE relay. Energize one coil to close it; energize the other coil to open it. This calls for a new paradigm in battery master switches. It's a fine product. My first question would explore expected return on investment for the purchase and installation of such a device. P.S. This product would perform well as a BATTERY contactor but poorly as a STARTER contactor. Bob . . . ________________________________ Message 7 _____________________________________ Time: 09:53:17 AM PST US From: Ed Holyoke Subject: Re: AeroElectric-List: Re: Master / Starter Relay The linen in them might make for a decent phenolic, properly laminated. I don't think the denomination will matter much. ;-) Ed On 4/26/2013 8:57 AM, Holger Selover-Stephan wrote: > --> AeroElectric-List message posted by: Holger Selover-Stephan > > > On Apr 26, 2013, at 6:29 AM, Bill Bradburry wrote: > >> If you glue dollar bills to the sides of the fuselage, it will make the >> fuselage a little stronger... :>) > > Interesting. From a structural standpoint, which bill is recommended: $1, $20, $50, ...? Probably the higher ones, you get what you pay for? > > Holger > > PS: Plugged my 40W LED landing light into the cigarette lighter on a flight the other day, and there was no RF noise. More tests needed. > > ________________________________ Message 8 _____________________________________ Time: 11:44:24 AM PST US From: Jeff Page Subject: AeroElectric-List: Re: 28V to 15.6V @ 5A Wow - lots of possibilities, far less expensive than the TSO unit I was looking at. Astrodyne has some very promising products, that are burnt in and have noise filtering built-in. I am going to suggest to him that we get one of these and try it out. Thanks Eric ! Bob - you found some interesting items too. Seller kuuco has some that I may purchase just to play with. Jay - I enjoyed your story. Even in Toronto, where everything is available, sometimes that is the cheapest way to obtain a part :-) Thanks everyone. Jeff Page Dream Aircraft Tundra #10 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.