---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 05/19/08: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:33 AM - Re: Re: Schematic Review (Ken) 2. 06:14 AM - Re: Re: S704-1 Relay Question (Andrew Butler) 3. 07:11 AM - Re: Re: S704-1 Relay Question (Ron Shannon) 4. 08:19 AM - Re: Re: S704-1 Relay Question (Andrew Butler) 5. 08:19 AM - Re: Schematic Review (user9253) 6. 08:36 AM - Re: Use of 700-2-10 switch for Voltage Sense - how to wire? (mikef) 7. 08:44 AM - Re: Re: S704-1 Relay Question (Etienne Phillips) 8. 08:46 AM - Re: Re: S704-1 Relay Question (Ron Shannon) 9. 09:17 AM - Re: Re: S704-1 Relay Question (Andrew Butler) 10. 01:11 PM - Re: Re: S704-1 Relay Question (Robert L. Nuckolls, III) 11. 03:27 PM - Re: Help for English translation (Gilles Thesee) 12. 03:41 PM - Re: battery tenders (skyking135) 13. 03:47 PM - Re: Re: Schematic Review (Dave Leikam) 14. 04:16 PM - Re: Help for English translation (Kevin Horton) 15. 07:29 PM - Re: battery tenders (earl_schroeder@juno.com) 16. 08:02 PM - Any legacy regulator gurus out there? (Robert L. Nuckolls, III) 17. 08:06 PM - Contactor Locations (Les Kearney) ________________________________ Message 1 _____________________________________ Time: 05:33:12 AM PST US From: Ken Subject: Re: AeroElectric-List: Re: Schematic Review I am skeptical whether paralleling a double pole switch really helps reliability. Mechanical switch failure would take out both poles. A lightly loaded switch might suffer corrosion and wear issues at a similar rate for both poles. One would not know if one pole failed prematurely. For heavily loaded contacts perhaps the second pole would help share the arc damage though?? Ken user9253 wrote: > > Suggestion 1. An avionics master switch is controversial because it becomes a single point failure for all of your avionics. Modern avionics are not supposed to be affected by voltage spikes. If concerned about expensive avionics, one could shut off individual units, not as convenient as a master switch but safer. If you must have an avionics master, consider using a double pole switch wired in parallel. If one half of the switch fails, the other half will carry the load. > ________________________________ Message 2 _____________________________________ Time: 06:14:45 AM PST US From: "Andrew Butler" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Hello, At what level of load does an E-Bus become "heavy duty"? Also, what is the purpose of the diode? I know what a diode does, but what is its practical use in this instance? Cheers, Andrew. ----- Original Message ----- From: "Robert L. Nuckolls, III" To: aeroelectric-list@matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Sun, 18 May 2008 22:31:42 -0500 At 02:34 PM 5/18/2008 -0700, you wrote: > > Bob: > > I'm going to install a "Heavy E-bus and use your architecture: Bat-bus > (14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay and 14 > awg from relay to e-bus. I'm a little confused on how the Relay is wired. > I've printed the wiring picture of the Relay off the aeroelectric website > and it didn't help. > > The diode, via fastabs is wired or jumps the - to + terminal and there are > also 2 wires crimped to the same fasttabs. I'm assuming the black goes to > ground, but where does the one wired to the + terminal go to ?? > > Also where does the "COM" wire and N.O. wire go? > > OR...keeping the question simple ---how do you wire the Relay utilizing > Heavy E-Bus architecture? > > Thanks As shown in http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z32K.pdf The picture at: http://aeroelectric.com/Pictures/Relays/s704inst.jpg shows how to get the diode leads into the same terminals with the wires that go to ends of the relay coil . . . but according to Z32K you'll need to drop two wires into the COM terminal too. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- =========== =========== =========== =========== ________________________________ Message 3 _____________________________________ Time: 07:11:49 AM PST US From: "Ron Shannon" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question On Mon, May 19, 2008 at 6:11 AM, Andrew Butler wrote: > Hello, > > At what level of load does an E-Bus become "heavy duty"? > > Also, what is the purpose of the diode? I know what a diode does, but what > is its practical use in this instance? > > Cheers, > > Andrew. > The level at which an E-bus becomes "heavy duty" is not a precise point, but certainly occurs when the E-bus is expected to carry loads that would strain or exceed limits for a standalone toggle switch. Although the S700 series switches are rated to 15A, you should probably be seriously considering a separate relay whenever load approaches 10A, IMHO. The diode keeps the E-bus from back feeding the Main bus when the E-bus alternate feed (direct from battery or battery bus) is ON. If the E-bus were allowed to back feed the Main bus, it would defeat the purpose of the E-bus, which is rapid, positive reduction of load upon alternator failure. Use of a diode instead of another switch eliminates the need to flip another switch (i.e., reduces chance for error, also, see "heavy duty" discussion above). Ron ________________________________ Message 4 _____________________________________ Time: 08:19:34 AM PST US From: "Andrew Butler" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Thanks Ron, though the diode I was referring is the 1N4001 across the coil of the S704 relay. There is something I don't know, cause I don't see it adding any functionality....... Andrew. ----- Original Message ----- From: "Ron Shannon" To: aeroelectric-list@matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Mon, 19 May 2008 07:07:20 -0700 On Mon, May 19, 2008 at 6:11 AM, Andrew Butler wrote: Hello, At what level of load does an E-Bus become "heavy duty"? Also, what is the purpose of the diode? I know what a diode does, but what is its practical use in this instance? Cheers, Andrew. The level at which an E-bus becomes "heavy duty" is not a precise point, but certainly occurs when the E-bus is expected to carry loads that would strain or exceed limits for a standalone toggle switch. Although the S700 series switches are rated to 15A, you should probably be seriously considering a separate relay whenever load approaches 10A, IMHO. The diode keeps the E-bus from back feeding the Main bus when the E-bus alternate feed (direct from battery or battery bus) is ON. If the E-bus were allowed to back feed the Main bus, it would defeat the purpose of the E-bus, which is rapid, positive reduction of load upon alternator failure. Use of a diode instead of another switch eliminates the need to flip another switch (i.e., reduces chance for error, also, see "heavy duty" discussion above). Ron =========== ======== === ________________________________ Message 5 _____________________________________ Time: 08:19:35 AM PST US Subject: AeroElectric-List: Re: Schematic Review From: "user9253" Hi Ken, I agree with you that a mechanical failure will disable both poles of a double pole switch. It has been my experience that the majority of switches fail because of high resistance between contacts, especially in switches that are not used frequently. I also agree that one would not know if only one pole failed. But who cares as long as the load keeps working? I am not suggesting that double pole switches be used in place of every single pole switch, only for essential applications. The added cost and weight for a couple of DPST switches is not much. Depending on one's panel, it could be a hassle replacing a switch. I would want to delay doing that by using a more reliable switch. I believe that a double pole switch wired in parallel has an extended life compared to a single pole switch. Maybe someone has already done tests to prove or disprove this theory. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183819#183819 ________________________________ Message 6 _____________________________________ Time: 08:36:54 AM PST US Subject: AeroElectric-List: Re: Use of 700-2-10 switch for Voltage Sense - how to wire? From: "mikef" Bob, My bad, I mixed up the switch types. I think I will stick with the small Digikey switch and be happy. Thanks again, Mike Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183822#183822 ________________________________ Message 7 _____________________________________ Time: 08:44:09 AM PST US From: "Etienne Phillips" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question It's called a fly-back diode. The coil of a relay is a fairly sizeable inductor, which means that a step-change in current is not really possible. What happens when the current to the coil is removed, the "inertia" of the inductor will force a current to continue flowing for a short while, generating large voltages and arcing across switch contacts. The fly-back diode gives this current a path to flow without interfering with the rest of the electrical system, and only comes into play when the coil is de-energized. For more info, go to http://en.wikipedia.org/wiki/Flyback_diode :-) Etienne 2008/5/19 Andrew Butler : > Thanks Ron, though the diode I was referring is the 1N4001 across the coil > of the S704 relay. There is something I don't know, cause I don't see it > adding any functionality....... > > Andrew. > > ----- Original Message ----- > From: "Ron Shannon" > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: Re: S704-1 Relay Question > Date: Mon, 19 May 2008 07:07:20 -0700 > > On Mon, May 19, 2008 at 6:11 AM, Andrew Butler > wrote: > >> Hello, >> >> At what level of load does an E-Bus become "heavy duty"? >> >> Also, what is the purpose of the diode? I know what a diode does, but what >> is its practical use in this instance? >> >> Cheers, >> >> Andrew. >> > > > The level at which an E-bus becomes "heavy duty" is not a precise point, > but certainly occurs when the E-bus is expected to carry loads that would > strain or exceed limits for a standalone toggle switch. Although the S700 > series switches are rated to 15A, you should probably be seriously > considering a separate relay whenever load approaches 10A, IMHO. > > The diode keeps the E-bus from back feeding the Main bus when the E-bus > alternate feed (direct from battery or battery bus) is ON. If the E-bus were > allowed to back feed the Main bus, it would defeat the purpose of the E-bus, > which is rapid, positive reduction of load upon alternator failure. Use of a > diode instead of another switch eliminates the need to flip another switch > (i.e., reduces chance for error, also, see "heavy duty" discussion above). > > Ron > > * > > ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com > .matronics.com/contribution > * > > > * > > * > > ________________________________ Message 8 _____________________________________ Time: 08:46:42 AM PST US From: "Ron Shannon" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question On Mon, May 19, 2008 at 8:16 AM, Andrew Butler wrote: > Thanks Ron, though the diode I was referring is the 1N4001 across the coil > of the S704 relay. There is something I don't know, cause I don't see it > adding any functionality....... > > Andrew. > Ooops! So much for unwarranted assumptions. As for the diode across the coil, see http://www.aeroelectric.com/articles/spikecatcher.pdf Ron ________________________________ Message 9 _____________________________________ Time: 09:17:59 AM PST US From: "Andrew Butler" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Perfect! Thanks. ----- Original Message ----- From: "Ron Shannon" To: aeroelectric-list@matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Mon, 19 May 2008 08:43:42 -0700 On Mon, May 19, 2008 at 8:16 AM, Andrew Butler wrote: Thanks Ron, though the diode I was referring is the 1N4001 across the coil of the S704 relay. There is something I don't know, cause I don't see it adding any functionality....... Andrew. Ooops! So much for unwarranted assumptions. As for the diode across the coil, see http://www.aeroelectric.com/articles/spikecatcher.pdf Ron =========== ======== === ________________________________ Message 10 ____________________________________ Time: 01:11:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: S704-1 Relay Question At 01:11 PM 5/19/2008 +0000, you wrote: >Hello, > >At what level of load does an E-Bus become "heavy duty"? The e-bus was born of a time when many if not most builders could plan on and implement an endurance load of 5A or less. The rule-of-thumb for maximum protection level of an always hot wire in TC aircraft is 5A . . . so the idea of taking a 5A fused feeder off the battery bus to supply an e-bus through a panel mounted switch was well within the parameters of accepted practice in TC aircraft. As folks piled more stuff on the e-bus, 5A feeders wouldn't cut it any more so it became a tribute to accepted practice to add a mini battery contactor at the battery bus to provide a local control point for the e-bus alternate feed path. From a reliability perspective I really like the idea of staying with a toggle switch. Further, given that a 7A fuse is on the order of 5-10 times faster than a 5A breaker, it seems a reasonable tribute to accepted practice to say that anything over a 7A FUSED alternate feed path is "heavy duty" and justifies the complexity of an additional relay. 7A or less can be handled with a toggle switch. Bob . . . ________________________________ Message 11 ____________________________________ Time: 03:27:25 PM PST US From: Gilles Thesee Subject: Re: AeroElectric-List: Help for English translation Mickey Coggins a crit : > > > Hi Gilles, > > There is a MGL representative in France - perhaps he has already > contacted the DGAC. > > http://www.stratomaster.eu/ > > If the document you need translated is going to the boys in South > Africa, I'd say it is quite understandable. To make sure the > translation is accurate, it would help to have a link to the French > version. > Mickey and all, Thanks to all who responded, on-list and off-list. I added a link to the original French version at the bottom of the page http://contrails.free.fr/translate.php I understand that the translation is for the use of the French MGL representative. Thanks again, Best regards, -- Gilles http://contrails.free.fr ________________________________ Message 12 ____________________________________ Time: 03:41:39 PM PST US From: skyking135 Subject: Re: AeroElectric-List: battery tenders I have one of the 42292 units and measured the output voltage on my particular unit to be around 12.7 volts, noload. It was only getting the battery up to about 12.3 volts; not enough to keep a good charge on a battery. So, being the curious one that I am, I popped open the cover to see if I could figure out how to adjust the output voltage. I found a spot on the circuit board for a varistor (VR1) that had a 55ohm resistor soldered in that postion. I figured that must adjust the output voltage. I simply replaced the 55ohm resistor with a 22ohm one I had on hand. That boosted the ouptut to a more respectable 13.2 volts. It still will only charge up to about 12.9 volts which is better than the 12.3 is was reaching before. I think I will adjust the resistor again to see if I can squeeze out a little more performance. Quality control is not high on the list of priorities with Harbor Freight. You get what you pay for. db ________________________________ Message 13 ____________________________________ Time: 03:47:17 PM PST US From: "Dave Leikam" Subject: Re: AeroElectric-List: Re: Schematic Review I flew an Archer for a few years that had two avionics masters side by side wired parallel. Toggles will usually fail when turned on or off. If one failed (never did), you knew it and the other was available. Dave Leikam #40496 N89DA (Reserved) Muskego, WI ----- Original Message ----- From: "Ken" Sent: Monday, May 19, 2008 7:30 AM Subject: Re: AeroElectric-List: Re: Schematic Review > > I am skeptical whether paralleling a double pole switch really helps > reliability. Mechanical switch failure would take out both poles. A > lightly loaded switch might suffer corrosion and wear issues at a similar > rate for both poles. One would not know if one pole failed prematurely. > For heavily loaded contacts perhaps the second pole would help share the > arc damage though?? > Ken > > user9253 wrote: >> >> >> Suggestion 1. An avionics master switch is controversial because it >> becomes a single point failure for all of your avionics. Modern avionics >> are not supposed to be affected by voltage spikes. If concerned about >> expensive avionics, one could shut off individual units, not as >> convenient as a master switch but safer. If you must have an avionics >> master, consider using a double pole switch wired in parallel. If one >> half of the switch fails, the other half will carry the load. >> > > > ________________________________ Message 14 ____________________________________ Time: 04:16:35 PM PST US From: Kevin Horton Subject: Re: AeroElectric-List: Help for English translation On 19 May 2008, at 17:25, Gilles Thesee wrote: > > > Mickey Coggins a crit : >> matronics@rv8.ch> >> >> Hi Gilles, >> >> There is a MGL representative in France - perhaps he has already >> contacted the DGAC. >> >> http://www.stratomaster.eu/ >> >> If the document you need translated is going to the boys in South >> Africa, I'd say it is quite understandable. To make sure the >> translation is accurate, it would help to have a link to the >> French version. >> > > Mickey and all, > > Thanks to all who responded, on-list and off-list. > I added a link to the original French version at the bottom of the > page > http://contrails.free.fr/translate.php > > I understand that the translation is for the use of the French MGL > representative. > Many elements of these requirements appear to be lifted directly from CS 23, the European equivalent to FAR 23. You can find the accepted English wording for some sections by looking at FAR 23.1301, 23.1309, 23.1311, 23.1322, etc. Available on the FAA web site. -- Kevin Horton RV-8 (FInal Assembly) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 15 ____________________________________ Time: 07:29:54 PM PST US From: "earl_schroeder@juno.com" Subject: Re: AeroElectric-List: battery tenders Hi db, The older 42292 [or whatever (the previous generation)]did have a variable resister on the circuit board. Nearly every one needed some adjustment as I have a dozen or so. I purchased a minimum order of 100 ohm pots to install in the newer units. I adjust them for 13.8 open circuit. I've repaired six or so [mine and others] as the common failure is the transformer wire disconnects where it attaches to the plug that plugs into the 110VAC. A sharp knife will separate the plastic housing around the transformer providing access. I thought originally that trying to start an engine with the unit connected would melt the solder at that joint but I'm not sure. For the money they are hard to beat but as some say, you get what you pay for.. Earl -- skyking135 wrote: < I have one of the 42292 units and measured the output voltage on my particular unit to be around 12.7 volts, noload. It was only getting the battery up to about 12.3 volts; not enough to keep a good charge on a battery. So, being the curious one that I am, I popped open the cover to see if I could figure out how to adjust the output voltage. I found a spot on the circuit board for a varistor (VR1) that had a 55ohm resistor soldered in that postion. I figured that must adjust the output voltage. I simply replaced the 55ohm resistor with a 22ohm one I had on hand. That boosted the ouptut to a more respectable 13.2 volts. It still will only charge up to about 12.9 volts which is better than the 12.3 is was reaching before. I think I will adjust the resistor again to see if I can squeeze out a little more performance. Quality control is not high on the list of priorities with Harbor Freight. You get what you pay for. db ________________________________ Message 16 ____________________________________ Time: 08:02:59 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Any legacy regulator gurus out there? I received some pictures from a reader who is looking for an adjustment procedure for a Delco-Remy generator regulator. http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_4.jpg http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_3.jpg http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_2.jpg http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_1.jpg I've never seen an electro-mechanical regulator that was this sophisticated. It appears to have airgap adjustments as well as spring tension adjustments for both the V-reg and I-lim relays. I'm wondering if anyone on this IS or KNOWS someone WHO IS familiar adjustment of these devices. I'm afraid that the "offical" procedure will require test equipment common to a generator/regulator overhaul shop. Unless I can find data specific to this device (I think the 12VN7E numbers on the base plate are a part number) I'm going to recommend that he not mess with anything other than the tension spring on the voltage regulator which can be adjusted with the engine running and a light load on the system. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 17 ____________________________________ Time: 08:06:51 PM PST US From: Les Kearney Subject: AeroElectric-List: Contactor Locations Hi I am trying to plan my RV10 electrical system and have a question for the electrical mavens. That is, how far from avionics should battery contactors be? I am looking at mounting my batteries in the sub panel area and would like to co-locate the contactors in the same area. Access is not an issue but I am concerned about possible interference with the avionics. I may end up locating the starter contactor on the same area as well. Would this be a problem? Cheers Les Kearney ------------------------------------------------------------------------------------- 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.