---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/16/09: 18 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:01 AM - Re: Splicing wire (N395V) 2. 06:38 AM - Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? (Robert L. Nuckolls, III) 3. 07:18 AM - Re: Re: Splicing wire (Bob Collins) 4. 08:34 AM - E-Buss and Master Switches (David Nelson) 5. 09:50 AM - Re: Re: Splicing wire (Robert L. Nuckolls, III) 6. 10:23 AM - Re: E-Buss and Master Switches (Jay Hyde) 7. 11:37 AM - Re: E-Buss and Master Switches (Robert L. Nuckolls, III) 8. 11:38 AM - Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? (Robert L. Nuckolls, III) 9. 12:45 PM - Re: E-Buss and Master Switches (David Nelson) 10. 01:12 PM - Re: E-Buss and Master Switches (David Nelson) 11. 01:54 PM - Re: E-Buss and Master Switches (Jay Hyde) 12. 02:24 PM - Re: E-Buss and Master Switches (Robert L. Nuckolls, III) 13. 02:37 PM - Re: E-Buss and Master Switches (Robert L. Nuckolls, III) 14. 03:12 PM - Re: E-Buss and Master Switches (David Nelson) 15. 03:26 PM - VOM Troubles (Dennis Johnson) 16. 05:07 PM - Re: Check this out (Walter Fellows) 17. 06:50 PM - Re: Check this out (Robert L. Nuckolls, III) 18. 07:48 PM - Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? (Allen Fulmer) ________________________________ Message 1 _____________________________________ Time: 05:01:11 AM PST US Subject: AeroElectric-List: Re: Splicing wire From: "N395V" Bob, I would consider a lash splice............ http://workmanship.nasa.gov/guidadv_recmeth_lashsplice.jsp covered with heatshrink. -------- Milt 2003 F1 Rocket 2006 Radial Rocket Read this topic online here: http://forums.matronics.com/viewtopic.php?p=257954#257954 Attachments: http://forums.matronics.com//files/guidadv_recmeth_lash0_213.jpg ________________________________ Message 2 _____________________________________ Time: 06:38:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 12 volt 3 or 4 pole relay for 1 to 2 amp load? At 09:18 PM 8/15/2009, you wrote: >Hello Bob, > >I want to add a little 3 pole relay to turn a Trutrak Flight Systems >Automatic Pitch Trim on and off. (I did not consider this >capability when I was running my wire bundle to the pitch servo area >though I do have a spare pair that could be used to control a relay.) > >Page 7 of the Trutrak manual has the wiring diagram for their Auto >Trim module. > >http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf > >Can you recommend a relay that might be carried by Allied >Electronics? http://www.alliedelec.com/ > >I don't think you sell such a critter. Allied has a lot of choices. This one is suited to your task: http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912&MPN=LY3F-DC12 http://www.alliedelec.com/Images/Products/Datasheets/BM/OMRON_ELECTRONICS_LLC/821-0906.PDF Emacs! Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 3 _____________________________________ Time: 07:18:54 AM PST US From: "Bob Collins" Subject: RE: AeroElectric-List: Re: Splicing wire Excellent, Milt. Thank you. B -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of N395V Sent: Sunday, August 16, 2009 6:59 AM Subject: AeroElectric-List: Re: Splicing wire --> Bob, I would consider a lash splice............ http://workmanship.nasa.gov/guidadv_recmeth_lashsplice.jsp covered with heatshrink. -------- Milt 2003 F1 Rocket 2006 Radial Rocket Read this topic online here: http://forums.matronics.com/viewtopic.php?p=257954#257954 Attachments: http://forums.matronics.com//files/guidadv_recmeth_lash0_213.jpg ________________________________ Message 4 _____________________________________ Time: 08:34:46 AM PST US From: David Nelson Subject: AeroElectric-List: E-Buss and Master Switches Hi Bob, I'm going over the finer details of a design based largely upon Z-11. Why wouldn't one, for normal ops, have both the E-Buss and Master in the 'On' position? My reasoning being: - In the event of some electrical problems, you only have to contend with switching off one switch rather than remembering to turn the E-buss 'On' followed by turning the Master 'Off'. - If the problem persists, we aren't in any different position than if we turned on the E-Buss followed by turning off the Master. Am I missing something fundamental here or was I always assuming that the E-Buss was always originally 'Off' during normal ops? Thank you, /\/elson ________________________________ Message 5 _____________________________________ Time: 09:50:43 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Splicing wire At 06:59 AM 8/16/2009, you wrote: > >Bob, > >I would consider a lash splice............ > >http://workmanship.nasa.gov/guidadv_recmeth_lashsplice.jsp > >covered with heatshrink. That works good. We've published similar processes on aeroelectric.com Solder and insulate techniques range from the simple processes described above to the more sophisticated (and expensive) process illustrated here: http://parts.digikey.com/1/parts-kws/solder-sleeve Any methodology that achieves good mechanical and electrical joining of the wires followed by robust insulation will serve your purposes. The simplest processes are recommended. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 6 _____________________________________ Time: 10:23:44 AM PST US From: "Jay Hyde" Subject: RE: AeroElectric-List: E-Buss and Master Switches Hi there David, I had to write a procedure on how to use a system that I wired to one of the Z diagrams and then it became clear why one does not want to leave the e-bus alt feed on. In the event of a fault, smoke, what have you, the first thing that you want to do is isloate the power sources from the fault as fast as possible- hence the DC master; once its off only the short fat wire between the battery and your solenoid is live (and the E-bus alt to the switch wire). So, unless the fault is right there (usually unlikely), then you have removed the power that is driving the fault. In a mag equipped aircraft the engine should still run and in an all electric aircraft the ECU and fuel pumps should have directly connected wires that bypass the DC master. If you still have smoke and trouble then you know that you are now seriously in the dwang, as the fault is somewhere in those, non-isolatable, wires. However, if switching the DC master off clears the fault you can now switch the E-bus alt feed on and see what happens; then maybe switch off a few circuits on the main bus; switch the DC master back on, etc. This is assuming that landing is not a luxury that you are presently afforded- such as if you are crossing the Atlantic and you're 10 hours into a 22 hour flight... ;-) If you can land, better to figure the problem out on the ground of course, using just the E-bus to get you down. Jay -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David Nelson Sent: 16 August 2009 05:30 PM Subject: AeroElectric-List: E-Buss and Master Switches Hi Bob, I'm going over the finer details of a design based largely upon Z-11. Why wouldn't one, for normal ops, have both the E-Buss and Master in the 'On' position? My reasoning being: - In the event of some electrical problems, you only have to contend with switching off one switch rather than remembering to turn the E-buss 'On' followed by turning the Master 'Off'. - If the problem persists, we aren't in any different position than if we turned on the E-Buss followed by turning off the Master. Am I missing something fundamental here or was I always assuming that the E-Buss was always originally 'Off' during normal ops? Thank you, /\/elson ________________________________ Message 7 _____________________________________ Time: 11:37:14 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: E-Buss and Master Switches At 10:30 AM 8/16/2009, you wrote: > > >Hi Bob, > >I'm going over the finer details of a design based largely upon >Z-11. Why wouldn't one, for normal ops, have both the E-Buss and >Master in the 'On' position? Could, but not necessary. Doesn't hurt. But you DO want to pre-flight test the dual power path philosophy for the e-bus. >My reasoning being: > >- In the event of some electrical problems, you only have to contend >with switching off one switch rather than remembering to turn the >E-buss 'On' followed by turning the Master 'Off'. Remember? It's recommended that you have a checklist for shutdown. It's also recommended that you consider an ergonomic arrangement of switches wherein ship's DC power controls are grouped. Leaving the airplane should be preceded by placing all switches down (OFF). >- If the problem persists, we aren't in any different position than >if we turned on the E-Buss followed by turning off the Master. > >Am I missing something fundamental here or was I always assuming >that the E-Buss was always originally 'Off' during normal ops? That was the original design philosophy. But failure mode effects analysis for the system's design included consideration of risk for having the switch ON under any flight conditions. Wired as shown, you may operate it with any philosophy you choose. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 8 _____________________________________ Time: 11:38:29 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 12 volt 3 or 4 pole relay for 1 to 2 amp load? At 09:18 PM 8/15/2009, you wrote: >Hello Bob, > >I want to add a little 3 pole relay to turn a Trutrak Flight Systems >Automatic Pitch Trim on and off. (I did not consider this >capability when I was running my wire bundle to the pitch servo area >though I do have a spare pair that could be used to control a relay.) > >Page 7 of the Trutrak manual has the wiring diagram for their Auto >Trim module. > >http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf > >Can you recommend a relay that might be carried by Allied >Electronics? http://www.alliedelec.com/ > >I don't think you sell such a critter. Allied has a lot of choices. This one is suited to your task: http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912&MPN=LY3F-DC12 http://www.alliedelec.com/Images/Products/Datasheets/BM/OMRON_ELECTRONICS_LLC/821-0906.PDF Emacs! Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 9 _____________________________________ Time: 12:45:27 PM PST US From: David Nelson Subject: RE: AeroElectric-List: E-Buss and Master Switches Hi Jay, I certainly understand your reasoning for the below and I had a similar argument in my head. But then this scenario popped up in my head. Currently, I'm only VFR rated but plan to go for the IFR ticket within a couple of years of project completion. I imagined flying in the soup and would I want to reset all my avionics and wait for them to reinitialize? I'll be honest, I don't how long it will take for my equipment to re-initialize while flying - I'll add it as a 'todo' item for further investigation. Ugh - this is making my head hurt. To me, I guess what it comes down to is that we must architect our systems for fault tolorance, know how the systems are designed and how they work, understand the associated risks and trade-offs, and train for emergencies. Thanks to Bob, we can thank him for the 1st three. /\/elson On Sun, 16 Aug 2009, Jay Hyde wrote: > > > Hi there David, > > I had to write a procedure on how to use a system that I wired to one of the > Z diagrams and then it became clear why one does not want to leave the e-bus > alt feed on. In the event of a fault, smoke, what have you, the first thing > that you want to do is isloate the power sources from the fault as fast as > possible- hence the DC master; once its off only the short fat wire between > the battery and your solenoid is live (and the E-bus alt to the switch > wire). So, unless the fault is right there (usually unlikely), then you > have removed the power that is driving the fault. In a mag equipped > aircraft the engine should still run and in an all electric aircraft the ECU > and fuel pumps should have directly connected wires that bypass the DC > master. If you still have smoke and trouble then you know that you are now > seriously in the dwang, as the fault is somewhere in those, non-isolatable, > wires. > However, if switching the DC master off clears the fault you can now switch > the E-bus alt feed on and see what happens; then maybe switch off a few > circuits on the main bus; switch the DC master back on, etc. This is > assuming that landing is not a luxury that you are presently afforded- such > as if you are crossing the Atlantic and you're 10 hours into a 22 hour > flight... ;-) > > If you can land, better to figure the problem out on the ground of course, > using just the E-bus to get you down. > > Jay > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David > Nelson > Sent: 16 August 2009 05:30 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: E-Buss and Master Switches > > > > > Hi Bob, > > I'm going over the finer details of a design based largely upon Z-11. Why > wouldn't one, for normal ops, have both the E-Buss and Master in the 'On' > position? > > My reasoning being: > > - In the event of some electrical problems, you only have to contend with > switching off one switch rather than remembering to turn the E-buss 'On' > followed by turning the Master 'Off'. > > - If the problem persists, we aren't in any different position than if we > turned on the E-Buss followed by turning off the Master. > > Am I missing something fundamental here or was I always assuming that the > E-Buss was always originally 'Off' during normal ops? > > Thank you, > /\/elson > > ________________________________ Message 10 ____________________________________ Time: 01:12:34 PM PST US From: David Nelson Subject: Re: AeroElectric-List: E-Buss and Master Switches Hi Bob, 100% agree that the pre-flight checklist should involve toggling both swithches to ensure proper operation. That should be item regardless of normal ops. I'm giving an awful lot of thought to switch placement and overall cockpit ergonomics. Being my 1st time, I'm learning that it is not as easy as a task as I had thought it would be....and I am making progress. /\/elson On Sun, 16 Aug 2009, Robert L. Nuckolls, III wrote: > > > At 10:30 AM 8/16/2009, you wrote: >> >> >> >> Hi Bob, >> >> I'm going over the finer details of a design based largely upon Z-11. Why >> wouldn't one, for normal ops, have both the E-Buss and Master in the 'On' >> position? > > Could, but not necessary. Doesn't hurt. But you DO > want to pre-flight test the dual power path philosophy > for the e-bus. > >> My reasoning being: >> >> - In the event of some electrical problems, you only have to contend with >> switching off one switch rather than remembering to turn the E-buss 'On' >> followed by turning the Master 'Off'. > > Remember? It's recommended that you have a checklist > for shutdown. It's also recommended that you consider > an ergonomic arrangement of switches wherein ship's > DC power controls are grouped. Leaving the airplane > should be preceded by placing all switches down (OFF). > >> - If the problem persists, we aren't in any different position than if we >> turned on the E-Buss followed by turning off the Master. >> >> Am I missing something fundamental here or was I always assuming that the >> E-Buss was always originally 'Off' during normal ops? > > That was the original design philosophy. But failure > mode effects analysis for the system's design included > consideration of risk for having the switch ON under > any flight conditions. Wired as shown, you may operate > it with any philosophy you choose. > > > Bob . . . > > --------------------------------------- > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > --------------------------------------- > > ________________________________ Message 11 ____________________________________ Time: 01:54:34 PM PST US From: "Jay Hyde" Subject: RE: AeroElectric-List: E-Buss and Master Switches Hey David, I kinda agree... re waiting for stuff to reset; I suppose that the best is exactly what we are arming ourselves with right here- a pretty good understanding of exactly how our sytems work. As an aside, the MGL EFIS systems that I am using a lot now have the option (as many others also do) of their own standby and backup battery ( a little isty bitsy thing) that keeps them all running when you switch off the DC master- sort of like an airborne UPS you might say; so the reset doesn't really happen :-) I hope... ;-) Jay -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David Nelson Sent: 16 August 2009 09:44 PM Subject: RE: AeroElectric-List: E-Buss and Master Switches Hi Jay, I certainly understand your reasoning for the below and I had a similar argument in my head. But then this scenario popped up in my head. Currently, I'm only VFR rated but plan to go for the IFR ticket within a couple of years of project completion. I imagined flying in the soup and would I want to reset all my avionics and wait for them to reinitialize? I'll be honest, I don't how long it will take for my equipment to re-initialize while flying - I'll add it as a 'todo' item for further investigation. Ugh - this is making my head hurt. To me, I guess what it comes down to is that we must architect our systems for fault tolorance, know how the systems are designed and how they work, understand the associated risks and trade-offs, and train for emergencies. Thanks to Bob, we can thank him for the 1st three. /\/elson On Sun, 16 Aug 2009, Jay Hyde wrote: > > > Hi there David, > > I had to write a procedure on how to use a system that I wired to one of the > Z diagrams and then it became clear why one does not want to leave the e-bus > alt feed on. In the event of a fault, smoke, what have you, the first thing > that you want to do is isloate the power sources from the fault as fast as > possible- hence the DC master; once its off only the short fat wire between > the battery and your solenoid is live (and the E-bus alt to the switch > wire). So, unless the fault is right there (usually unlikely), then you > have removed the power that is driving the fault. In a mag equipped > aircraft the engine should still run and in an all electric aircraft the ECU > and fuel pumps should have directly connected wires that bypass the DC > master. If you still have smoke and trouble then you know that you are now > seriously in the dwang, as the fault is somewhere in those, non-isolatable, > wires. > However, if switching the DC master off clears the fault you can now switch > the E-bus alt feed on and see what happens; then maybe switch off a few > circuits on the main bus; switch the DC master back on, etc. This is > assuming that landing is not a luxury that you are presently afforded- such > as if you are crossing the Atlantic and you're 10 hours into a 22 hour > flight... ;-) > > If you can land, better to figure the problem out on the ground of course, > using just the E-bus to get you down. > > Jay > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David > Nelson > Sent: 16 August 2009 05:30 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: E-Buss and Master Switches > > > > > Hi Bob, > > I'm going over the finer details of a design based largely upon Z-11. Why > wouldn't one, for normal ops, have both the E-Buss and Master in the 'On' > position? > > My reasoning being: > > - In the event of some electrical problems, you only have to contend with > switching off one switch rather than remembering to turn the E-buss 'On' > followed by turning the Master 'Off'. > > - If the problem persists, we aren't in any different position than if we > turned on the E-Buss followed by turning off the Master. > > Am I missing something fundamental here or was I always assuming that the > E-Buss was always originally 'Off' during normal ops? > > Thank you, > /\/elson > > ________________________________ Message 12 ____________________________________ Time: 02:24:42 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: E-Buss and Master Switches At 02:56 PM 8/16/2009, you wrote: > > >Hi Bob, > >100% agree that the pre-flight checklist should involve toggling >both swithches to ensure proper operation. That should be item >regardless of normal ops. > >I'm giving an awful lot of thought to switch placement and overall >cockpit ergonomics. Being my 1st time, I'm learning that it is not >as easy as a task as I had thought it would be....and I am making progress. Add this drawing to your sources of ideas . . . http://www.aeroelectric.com/PPS/Switch_Panels/Switches.pdf In several variations I've suggested an ordering of switches that groups function and mitigates the effects of mistakenly grabbing an adjacent switch. Operating the wrong switch is high on the list of concerns for some builders. Here I've built the switch strings where the least used are at the far left and most used at far right with power distribution and control in the middle. You may have other design goals in mind but these drawings may offer a place to start. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 13 ____________________________________ Time: 02:37:44 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: E-Buss and Master Switches >I imagined flying in the soup and would I want to reset all my >avionics and wait for them to reinitialize? I'll be honest, I don't >how long it will take for my equipment to re-initialize while flying >- I'll add it as a 'todo' item for further investigation. I forgot another item from your posting. If it's ever necessary to force any piece of equipment to re-boot, it's ill-advised to initiate it with any part of the power distribution system that affects more than one piece of equipment. Any such processes are best accomplished on one piece at a time with controls unique to that piece of equipment and then perhaps only if you really need that piece of equipment for comfortable completion of that flight. More than one dark-n-stormy night story advanced to higher levels of interest and intrigue as pilot attempts to diagnose/fix some problem by manipulation that serves only distracted him or made other things happen that worsened the situation. >Ugh - this is making my head hurt. To me, I guess what it comes down >to is that we must architect our systems for fault tolorance, know >how the systems are designed and how they work, understand the >associated risks and trade-offs, and train for emergencies. Thanks >to Bob, we can thank him for the 1st three. It shouldn't be painful. It's called failure mode effects analysis and generally takes a LONG time to do a good job. Not that it's difficult . . . but new possibilities or combinations arise with thought, time and conversation with others. I'm pretty sure that every FMEA report I've submitted was considered by others "complete" and suitable for publication. Personally, I've considered them perhaps 99 percent complete while keeping an eye out for new ideas. Don't rush it. The thing that's nice about the airplanes we build here is that the last 1% item can be accommodated in a timely manner and at our convenience. The TC airplane guys HAD to call the work 100% complete because any changes after certification was a horribly protracted process. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 14 ____________________________________ Time: 03:12:40 PM PST US From: David Nelson Subject: RE: AeroElectric-List: E-Buss and Master Switches Hi Jay, "Airborne UPS" - haha - I like that. I had been resistant to using the internal battery option of the AFS unit. Instead opting for a small aux battery. I've recently changed my mind on that front as it somewhat simplyflied my panel and wiring while still maintaining the goal of being able to power up the EFIS before engine startup. After that, everthing else can get turned on. /\/elson On Sun, 16 Aug 2009, Jay Hyde wrote: > > > Hey David, > > I kinda agree... re waiting for stuff to reset; I suppose that the best is > exactly what we are arming ourselves with right here- a pretty good > understanding of exactly how our sytems work. > > As an aside, the MGL EFIS systems that I am using a lot now have the option > (as many others also do) of their own standby and backup battery ( a little > isty bitsy thing) that keeps them all running when you switch off the DC > master- sort of like an airborne UPS you might say; so the reset doesn't > really happen :-) I hope... ;-) > > Jay > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David > Nelson > Sent: 16 August 2009 09:44 PM > To: aeroelectric-list@matronics.com > Subject: RE: AeroElectric-List: E-Buss and Master Switches > > > > > Hi Jay, > > I certainly understand your reasoning for the below and I had a similar > argument in my head. But then this scenario popped up in my head. > Currently, > I'm only VFR rated but plan to go for the IFR ticket within a couple of > years > of project completion. I imagined flying in the soup and would I want to > reset > all my avionics and wait for them to reinitialize? I'll be honest, I don't > how > long it will take for my equipment to re-initialize while flying - I'll add > it > as a 'todo' item for further investigation. > > Ugh - this is making my head hurt. To me, I guess what it comes down to is > that > we must architect our systems for fault tolorance, know how the systems are > designed and how they work, understand the associated risks and trade-offs, > and > train for emergencies. Thanks to Bob, we can thank him for the 1st three. > > /\/elson > > On Sun, 16 Aug 2009, Jay Hyde wrote: > >> >> >> Hi there David, >> >> I had to write a procedure on how to use a system that I wired to one of > the >> Z diagrams and then it became clear why one does not want to leave the > e-bus >> alt feed on. In the event of a fault, smoke, what have you, the first > thing >> that you want to do is isloate the power sources from the fault as fast as >> possible- hence the DC master; once its off only the short fat wire > between >> the battery and your solenoid is live (and the E-bus alt to the switch >> wire). So, unless the fault is right there (usually unlikely), then you >> have removed the power that is driving the fault. In a mag equipped >> aircraft the engine should still run and in an all electric aircraft the > ECU >> and fuel pumps should have directly connected wires that bypass the DC >> master. If you still have smoke and trouble then you know that you are > now >> seriously in the dwang, as the fault is somewhere in those, > non-isolatable, >> wires. >> However, if switching the DC master off clears the fault you can now > switch >> the E-bus alt feed on and see what happens; then maybe switch off a few >> circuits on the main bus; switch the DC master back on, etc. This is >> assuming that landing is not a luxury that you are presently afforded- > such >> as if you are crossing the Atlantic and you're 10 hours into a 22 hour >> flight... ;-) >> >> If you can land, better to figure the problem out on the ground of course, >> using just the E-bus to get you down. >> >> Jay >> >> -----Original Message----- >> From: owner-aeroelectric-list-server@matronics.com >> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David >> Nelson >> Sent: 16 August 2009 05:30 PM >> To: aeroelectric-list@matronics.com >> Subject: AeroElectric-List: E-Buss and Master Switches >> >> >> >> >> Hi Bob, >> >> I'm going over the finer details of a design based largely upon Z-11. Why >> wouldn't one, for normal ops, have both the E-Buss and Master in the 'On' >> position? >> >> My reasoning being: >> >> - In the event of some electrical problems, you only have to contend with >> switching off one switch rather than remembering to turn the E-buss 'On' >> followed by turning the Master 'Off'. >> >> - If the problem persists, we aren't in any different position than if we >> turned on the E-Buss followed by turning off the Master. >> >> Am I missing something fundamental here or was I always assuming that the >> E-Buss was always originally 'Off' during normal ops? >> >> Thank you, >> /\/elson >> >> >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 15 ____________________________________ Time: 03:26:25 PM PST US Subject: AeroElectric-List: VOM Troubles From: "Dennis Johnson" I have a Fluke model 87 digital VOM (Volt-Ohm-Milliammeter) that has just started discharging the internal 9 volt battery in less than a month while it is turned OFF. I've had this meter for 15 years and used it throughout building my airplane, as well as various hobbies before that, so I guess I got my money's worth out of it, but I'm puzzled. Using another meter, I measured about 10 microamps current out of the Fluke's internal 9 volt transistor radio battery while it's turned OFF. If a 9 volt transistor radio battery holds 0.5 amp-hours, then with 10 microamps, the battery should last 50,000 hours. But the last two batteries lasted about a month each. They test good before I put them in and have an expiration date of 2013. First, is my arithmetic correct? I think a milliamp is 0.001 amps and a microamp is 0.000001 amps. I think a 10 microamp current through a half amp-hour battery would take 50,000 hours to deplete the battery. Second, did I read my digital VOM correctly? Using a nice German BBC VOM, set on the 2 milliamp scale, it reads .009. Using a cheap Harbor Freight digital VOM, set on the 200 microamp scale, it reads 09.5. You can see that something is wrong, either with my math or the way I'm reading the scale on the VOMs. Or maybe the Duracell fairies are sneaking in and sucking all the juice out of my batteries? I talked to Fluke customer support and he said there was no published spec on the current draw from the battery while it was turned off and couldn't say if mine was bad or not. My model 87 isn't supported anymore and he wanted me to buy the new version. Any ideas? Dennis Johnson Lancair Legacy, 330 flight hours Read this topic online here: http://forums.matronics.com/viewtopic.php?p=258060#258060 ________________________________ Message 16 ____________________________________ Time: 05:07:23 PM PST US Subject: Re: AeroElectric-List: Check this out From: Walter Fellows There is wisdom in your message but it will be helpful to those of focusing on aeroelectrics if you can mark it off topic. at, Aug 8, 2009 at 6:49 PM, wrote: > It happened sometime during my generation (born 1935). Up until and duri ng > WWII, it was =93honorable=94 to be in the trades, working with your hands .. > Sometime after WWII, and before the =93information age=94, in my world, i t > became imperative to go to college and earn a degree so that one didn=92t * > have* to work with ones hands. Somehow, using brainpower instead of > muscle power became =93noble=94. There are those among us that choose to use > both. We are the =93tinkerers=94. We are driven to learn, experiment an d to > create. But we are the dinosaurs, a dying breed. Beyond the time when i t > was a given that a college education was all that was necessary to succee d, > along came the computer. Today=92s youth (and some ancients) think that y ou > can do anything if you can conquer the computer. Never mind what makes i t > work. You only need to master the keyboard, the display and a host of > programming tricks. This mentality leads one to believe that =93stuff=94 > happens without human intervention, except through the computer=92s omnip otent > power. Thus the decline in people that really make =93stuff=94 happen - t he > carpenters, millwrights, farmers, machinist, plumbers, mechanics - all th ose > that work with their hands. Of course, they are still out there, doing t he > everyday jobs that must be done, but their numbers are rapidly declining; > =91cause it=92s just not E2cool=94 to work with your hands these days. B y all > means, allow and encourage the kids to master the computer. Just don=92t let > it get in the way of learning about and doing things manually, creating a nd > above all - =93TINKERING=94. > > Jay Bannister > ------------------------------ > Email message sent from CompuServe - visit us today at http://www.cs.com > > * > =========== =========== =========== =========== > * > > ________________________________ Message 17 ____________________________________ Time: 06:50:35 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Check this out At 06:56 PM 8/16/2009, you wrote: >There is wisdom in your message but it will be helpful to those of >focusing on aeroelectrics if you can mark it off topic. But it was on topic to the thread I originally posted under that subject . . . Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 18 ____________________________________ Time: 07:48:46 PM PST US From: "Allen Fulmer" Subject: RE: AeroElectric-List: 12 volt 3 or 4 pole relay for 1 to 2 amp load? Thank you BobN and BobMc. Do not archive From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Sunday, August 16, 2009 1:38 PM Subject: Re: AeroElectric-List: 12 volt 3 or 4 pole relay for 1 to 2 amp load? At 09:18 PM 8/15/2009, you wrote: Hello Bob, I want to add a little 3 pole relay to turn a Trutrak Flight Systems Automatic Pitch Trim on and off. (I did not consider this capability when I was running my wire bundle to the pitch servo area though I do have a spare pair that could be used to control a relay.) Page 7 of the Trutrak manual has the wiring diagram for their Auto Trim module. http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf Can you recommend a relay that might be carried by Allied Electronics? http://www.alliedelec.com/ I don't think you sell such a critter. Allied has a lot of choices. This one is suited to your task: http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912 &MPN=LY3F-DC12 http://www.alliedelec.com/Images/Products/Datasheets/BM/OMRON_ELECTRONICS_LL C/821-0906.PDF Emacs! 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