---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 06/23/08: 20 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:23 AM - Re: Re: Diode Wiring () 2. 07:02 AM - Re: Re: Contactor Diodes (Robert L. Nuckolls, III) 3. 07:35 AM - Tru Trak ADI (Palvary) 4. 11:11 AM - Re: Battery Question? (Frank Stringham) 5. 11:44 AM - Re: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp (Ernest Christley) 6. 11:49 AM - Re: Battery Question? (Robert L. Nuckolls, III) 7. 12:10 PM - (Robert L. Nuckolls, III) 8. 12:10 PM - Re: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp (Tony Babb) 9. 12:39 PM - Re: Tru Trak ADI (Mike) 10. 12:45 PM - Re: Battery Question? (ROGER & JEAN CURTIS) 11. 12:52 PM - Re: (David E. Nelson) 12. 01:01 PM - Re: Tru Trak ADI (Glaeser, Dennis A) 13. 01:17 PM - Re: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp (Harley) 14. 01:21 PM - Dual Comm Antenna Spacing (Valovich, Paul) 15. 02:40 PM - Re: Dual Comm Antenna Spacing () 16. 04:03 PM - Re: Dimmer trick (N601RT) 17. 05:51 PM - Re: Contactor Diodes (Joe) 18. 07:21 PM - Re: Contactor Diodes (Robert Feldtman) 19. 09:29 PM - Re: Contactor Diodes (Joemotis@aol.com) 20. 11:12 PM - Re: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp (Vernon Little) ________________________________ Message 1 _____________________________________ Time: 06:23:28 AM PST US Subject: RE: AeroElectric-List: Re: Diode Wiring From: Just and FYI, I've had my master to eBus B & C diode installed for about 3 weeks. After as much as 8 hours at 10-12 amps, it doesn't even get warm to the touch. I am using #10 wire for the 3 inch jumper with a 15 amp fuse. I have my diode wired to one terminal. At 3 - 9 amps with a heat sink installed you won't even know it's on. On the other hand my Garmin stack is going to make a good cabin heater this winter. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Sunday, June 22, 2008 8:26 AM Subject: Re: AeroElectric-List: Re: Diode Wiring --> > > > > >Just received the diode assembly from B&C for the main bus to > > >endurance bus wiring. The wiring diagram that came with it shows > > >two of its terminals joined going to the main bus. In the Aero > > >Connection, Bob says only one of the terminals goes to the main bus > > >and the other two can be removed. > > > > > >Please clarify--which is correct? > > > > Flip a coin . . . it doesn't matter much. > > SOMETIMES . . . the two paralleled diodes > > match close enough to sort-of share the > > loads but It's poor practice to depend on > > it. How big are your e-bus loads? > > > > Bob . . . > > >E-BUS loads about 3.5 amps; maximum 9.5. >Roger. Mount the diode to a metal surface, wiring to one diode is sufficient, two diodes doesn't hurt anything. Bob . . . ________________________________ Message 2 _____________________________________ Time: 07:02:08 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Contactor Diodes At 08:18 PM 6/22/2008 -0500, you wrote: >Bob, > >I think I mis-stated question 2. What I meant to say was, why would the >spike be stopped by the diode when it could more easily travel through the >coil wire directly to the opening switch? > >In reading your reply carefully, I believe I might be misunderstanding the >actual flow of energy in this instance. When you say that the diode is >positioned to conduct for any voltage that attempts to go more negative >than ground, are you saying that the spike will be conducted through the >diode (in the direction of the arrow) and back to the coil, and that this >cycle will continue until the resistance of the coil dissipates it? If >so, what makes the diode a preferred path over the path through the wire >to the opening switch? Is this just the nature of a diode? Reactive devices (capacitors and inductors) store energy. Capacitors in terms of the voltage to which they are charged and the value of their capacitance. The quantity of energy stored is J(watt-seconds)=(CE^2)/2 Inductors do the same thing with current where energy stored is J=(LI^2)/2 Capacitors can give up their energy in the form of high current pulses (like shorting a charged capacitor) while inductors are able to produce high voltages (when their magnetic fields are allowed to collapse without restraint). In the case of energy stored on an inductor like a starter or battery contactor coil, the breaking of the energizing circuit allows rapid collapse of the magnetic field within the inductor . . . and if totally unrestrained, can generate short spikes of voltage 300 volts or more. Obviously, this voltage will easily jump the gap in the relatively slow spreading contacts of the controlling switch. So as demonstrated on the bench and subsequent scope traces, a tiny fire is kindled between the spreading contacts and most of the store energy is dissipated in the stoking of that fire . . . with consequences to the surface of the contacts that reduce switch life. The goal is to re-route that energy. There's a host of methodologies, all perform as advertised and as dictated by the physics of their respective capabilities. A simple diode around the coil provides a shunt path for that energy that not only prevents the voltage from building at all, but causes it to dissipate almost totally within the resistance of the subject contactor coil. See: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg In views C and D, I show the path of electron flow for an energized contactor and a de-energized contactor. Note that the diode has no conduction in the energized mode (C) but provides an alternate path for electron flow in a tight loop (D) when the circuit is broken. This does cause the magnetic field to decay more slowly than if allowed to collapse unrestrained. A few weeks ago I published a trace that shows how the contactor or relay is delayed in reacting with a diode installed http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg . . . as opposed to no diode at all: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg Note in the first trace coil voltage is clamped off at just below ground (.7v diode drop) while in the second trace we see the voltage go WWWAAAaaaayyyy negative. In the second trace, had a fire been allowed to form between the spreading contacts of a switch, the energy dissipated would have removed metal from the contacts. In the first trace, arcing is a tiny fraction of what does happen when the stored energy is not managed. This whole discussion is about improving life of the controlling device with one of several techniques . . . with a simple diode being the simplest and easiest to acquire. >I apologize if I am taking up too much of this venue s resouces in trying >to understand this concept. If this is an issue, please let me know and I >will try to gain an understanding by finding someone locally to discuss in >more detail. This is a classroom, not a country club. New students and teachers come and go with a wide range of knowledge and skills. This venue's resources are dedicated to precisely the needs you have expressed. Bob . . . ________________________________ Message 3 _____________________________________ Time: 07:35:58 AM PST US From: "Palvary" Subject: AeroElectric-List: Tru Trak ADI I've noticed several subscribers here use the TruTrak ADI. I once talked with a company rep and I still have questions. I'm hoping some of you here can set me right. I need to find a replacement for my vacuum attitude indicator. I want a dedicated instrument, not an EFIS, and have been vacillating between the TruTrak and the MGL Attitude indicator (AV2/SP4) units. The MGL unit operates exactly like a traditional (absolute angle) attitude indicator and the inertial sensors seem to be very reliable. The TruTrak has a great display and can later be upgraded to an autopilot. However, it has some quirks that make it different from a traditional attitude indicator. >From what I understand, pitch information is only briefly displayed as an absolute angle and mostly is sustained by vertical airspeed information. Consequently, it would be possible, for example, to be flying slowly, pitch up without loosing altitude with the unit showing a level attitude. Maybe I'm too nervous, but if I was in clouds in this attitude I would want to know it. As for bank information, the TruTrak shows rate of change of bank angle, not absolute bank angle. So conceivably, one could be in a forward slip (not turning), but in a constant bank angle with the unit showing level flight. TruTrak says that the device is actually better/safer in the clouds than a conventional attitude inidicator. So my questions are: Do you like andd depend on your TruTrak ADI? Can the TruTrak entirely replace the traditional attitude indicator/horizon? Am I properly understanding how the pitch and bank display operates? --Jose ________________________________ Message 4 _____________________________________ Time: 11:11:39 AM PST US From: Frank Stringham Subject: RE: AeroElectric-List: Battery Question? Hi all Got a problem with my Odyssey 680 battery. It will not keep a charge. I am wired per Z13/8. Master and Endurance switches off. At first I thought the trickle from the Dynon 100 was the problem so I pull ed the trickle fuse from the battery bus. No joy!! so i pulled the fuse for the Dynon D100....No Joy. Pulled the main alternator CB...still no joy. Pu lled the the Aux (SD8 self excitation) alternator CB ..again no joy. I have checked all the various circuits on the fuse block (endurance/main) for a ny stray energy loss. My last idea is to charge the battery up again. Pull the ground from the ba ttery. Let it set a few days. Put the ground back on and check to see if it has lost amps..........If this is the case I would say I have a bad cell o r two in the battery. Any other ideas out there would be appreciated! Frank @ 1L8....RV7A...Last 949 details. ________________________________ Message 5 _____________________________________ Time: 11:44:00 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp Vernon Little wrote: > > For those who are not interested in the DIY approach, here's my link to a > tone annunciator module that will perform either active high or active low > sensing. For fans of Bob's work, there's actually a family of devices > inspired by what he's done, updated and packaged as complete products. This > includes a 10-channel audio mixer/amp (aka isolation amplifier), a stereo > music headphone amplifier and the tone annunciator. > > For more information: > www.vx-aviation.com > > Vernon, I tried to look at your website, but nothing displays. Is it working? ________________________________ Message 6 _____________________________________ Time: 11:49:32 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Battery Question? At 12:07 PM 6/23/2008 -0600, you wrote: > >Hi all > >Got a problem with my Odyssey 680 battery. It will not keep a charge. I am >wired per Z13/8. Master and Endurance switches off. >At first I thought the trickle from the Dynon 100 was the problem so I >pulled the trickle fuse from the battery bus. No joy!! so i pulled the >fuse for the Dynon D100....No Joy. Pulled the main alternator CB...still >no joy. Pulled the the Aux (SD8 self excitation) alternator CB ..again no >joy. I have checked all the various circuits on the fuse block >(endurance/main) for any stray energy loss. >My last idea is to charge the battery up again. Pull the ground from the >battery. Let it set a few days. Put the ground back on and check to see if >it has lost amps..........If this is the case I would say I have a bad >cell or two in the battery. > >Any other ideas out there would be appreciated! You've already done most of what I would suggest. I suspect the final experiment of leaving it disconnected for a few days will not yield a happily useful result . . . I'm betting the battery has some problems. I'm presuming that you KNOW the bus voltage in flight is such that you can EXPECT the battery to be fully charged when you park the airplane(?). Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 7 _____________________________________ Time: 12:10:20 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Was running low on AA cells and spotted a 36-pak of Ray-o-Vac on the shelves at Home Depot for about 0.31 per cell. Snatched up a package and put one of the little beasties on the battery-runner-downer-machine. The results are plotted at: http://www.aeroelectric.com/Pictures/Curves/AA_Battery_Tests_80622.jpg Seems this $low$ product is quite a bargain and contains more energy than most devices of the type. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 8 _____________________________________ Time: 12:10:25 PM PST US From: "Tony Babb" Subject: RE: AeroElectric-List: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp It works for me. I'm using Win2K with IE7. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ernest Christley Sent: Monday, June 23, 2008 11:41 AM Subject: Re: AeroElectric-List: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp --> Vernon Little wrote: > --> > > For those who are not interested in the DIY approach, here's my link > to a tone annunciator module that will perform either active high or > active low sensing. For fans of Bob's work, there's actually a family > of devices inspired by what he's done, updated and packaged as > complete products. This includes a 10-channel audio mixer/amp (aka > isolation amplifier), a stereo music headphone amplifier and the tone > annunciator. > > For more information: > www.vx-aviation.com > > Vernon, I tried to look at your website, but nothing displays. Is it working? ________________________________ Message 9 _____________________________________ Time: 12:39:50 PM PST US From: "Mike" Subject: RE: AeroElectric-List: Tru Trak ADI Jose, I will give you my best understanding of the Trutrak ADI vs. a standard attitude indicator. I have flown several that have the Trutrak ADI but I have not proactively used it (most of these airplanes had and EFIS or other primary instrument system). The Trutrak ADI seems easy to use but I don=92t know how well it would work as a primary unit for say being vectored of flying instrument transitions. I think the Trutrak ADI was designed to be a backup unit that would help you keep the dirty side down and still have confidence in flying vs. a turn and bank or turn coordinator. The roll information on the TT ADI is direct roll angle up to 45deg of zero, after that you have direction arrows. Most new attitude indicators will roll 360 degrees. Pitch on the TT ADI is direct pitch when not near level. When you near level it uses static information to figure vertical speed. This helps hold altitude without the use of an altimeter. As for you thought about the slip scenario, the unit shows angle not rate, so you would see that bank angle. Q1-A. I would only use it as a backup. Q2-A. Mostly no! It is limited to 45deg of bank and about 15 deg of pitch and requires functioning pitot static. The unit is not certified to any standard but I think it would make a good back-up. Q3-A. Explained above! Mike -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Palvary Sent: Monday, June 23, 2008 7:31 AM Subject: AeroElectric-List: Tru Trak ADI I've noticed several subscribers here use the TruTrak ADI. I once talked with a company rep and I still have questions. I'm hoping some of you here can set me right. I need to find a replacement for my vacuum attitude indicator. I want a dedicated instrument, not an EFIS, and have been vacillating between the TruTrak and the MGL Attitude indicator (AV2/SP4) units. The MGL unit operates exactly like a traditional (absolute angle) attitude indicator and the inertial sensors seem to be very reliable. The TruTrak has a great display and can later be upgraded to an autopilot. However, it has some quirks that make it different from a traditional attitude indicator. >From what I understand, pitch information is only briefly displayed as an absolute angle and mostly is sustained by vertical airspeed information. Consequently, it would be possible, for example, to be flying slowly, pitch up without loosing altitude with the unit showing a level attitude. Maybe I'm too nervous, but if I was in clouds in this attitude I would want to know it. As for bank information, the TruTrak shows rate of change of bank angle, not absolute bank angle. So conceivably, one could be in a forward slip (not turning), but in a constant bank angle with the unit showing level flight. TruTrak says that the device is actually better/safer in the clouds than a conventional attitude inidicator. So my questions are: Do you like andd depend on your TruTrak ADI? Can the TruTrak entirely replace the traditional attitude indicator/horizon? Am I properly understanding how the pitch and bank display operates? --Jose "http://www.matronics.com/Navigator?AeroElectric-List"http://www.matroni cs.com/Navigator?AeroElectric-List "http://forums.matronics.com"http://forums.matronics.com "http://www.matronics.com/contribution"http://www.matronics.com/contribu tion 10/2/2007 11:10 AM 10/2/2007 11:10 AM ________________________________ Message 10 ____________________________________ Time: 12:45:13 PM PST US From: "ROGER & JEAN CURTIS" Subject: RE: AeroElectric-List: Battery Question? -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Monday, June 23, 2008 2:41 PM Subject: RE: AeroElectric-List: Battery Question? At 12:07 PM 6/23/2008 -0600, you wrote: > >Hi all > >Got a problem with my Odyssey 680 battery. It will not keep a charge. I am >wired per Z13/8. Master and Endurance switches off. >At first I thought the trickle from the Dynon 100 was the problem so I >pulled the trickle fuse from the battery bus. No joy!! so i pulled the >fuse for the Dynon D100....No Joy. Pulled the main alternator CB...still >no joy. Pulled the the Aux (SD8 self excitation) alternator CB ..again no >joy. I have checked all the various circuits on the fuse block >(endurance/main) for any stray energy loss. >My last idea is to charge the battery up again. Pull the ground from the >battery. Let it set a few days. Put the ground back on and check to see if >it has lost amps..........If this is the case I would say I have a bad >cell or two in the battery. > >Any other ideas out there would be appreciated! You've already done most of what I would suggest. I suspect the final experiment of leaving it disconnected for a few days will not yield a happily useful result . . . I'm betting the battery has some problems. I'm presuming that you KNOW the bus voltage in flight is such that you can EXPECT the battery to be fully charged when you park the airplane(?). Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- If you pull one of the fat wires off the battery and check the current flow this will tell you if it is the battery or if you have an overlooked current flow somewhere in your wiring. Roger ________________________________ Message 11 ____________________________________ Time: 12:52:33 PM PST US From: "David E. Nelson" Subject: Re: AeroElectric-List: Excellent timing, Bob. I need to "recharge" my stash of AA's (sorry, couldn't resist). Thanks, /\/elson do not archive ~~ Lately my memory seems to be like a steel trap .... without any spring. ~~ On Mon, 23 Jun 2008, Robert L. Nuckolls, III wrote: > > > > Was running low on AA cells and spotted a 36-pak of > Ray-o-Vac on the shelves at Home Depot for about 0.31 > per cell. Snatched up a package and put one of the little > beasties on the battery-runner-downer-machine. The > results are plotted at: > > http://www.aeroelectric.com/Pictures/Curves/AA_Battery_Tests_80622.jpg > > Seems this $low$ product is quite a bargain and contains > more energy than most devices of the type. > > > Bob . . . > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > ________________________________ Message 12 ____________________________________ Time: 01:01:35 PM PST US Subject: AeroElectric-List: Re: Tru Trak ADI From: "Glaeser, Dennis A" I have an ADI Pilot II as my autopilot and attitude backup for my GRT Sport. It operates as you noted below regarding pitch and bank in those unusual situations. It is not a true 'attitude' indicator, it tells you what the airplane is doing with respect to altitude and heading. I find it very easy to use to control the plane (which is the ultimate requirement). I only have 50 hours on my plane, but TT has a great reputation for dependability. I'm a CFII, and using an ADI as the primary attitude instrument would require a bit of adjustment due to the special situations you've noted, however after a few hours of use I'd bet you would be quite comfortable with it. If you didn't recognize that you were flying slowly, or in a slip/skid situation, I'd contend that the instruments you're looking at are not the big problem :-) Hopefully you can find someone nearby that has an ADI that you can see and maybe even fly. Dennis Glaeser RV7A ------------------------------------------------------------------------ - I've noticed several subscribers here use the TruTrak ADI. I once talked with a company rep and I still have questions. I'm hoping some of you here can set me right. I need to find a replacement for my vacuum attitude indicator. I want a dedicated instrument, not an EFIS, and have been vacillating between the TruTrak and the MGL Attitude indicator (AV2/SP4) units. The MGL unit operates exactly like a traditional (absolute angle) attitude indicator and the inertial sensors seem to be very reliable. The TruTrak has a great display and can later be upgraded to an autopilot. However, it has some quirks that make it different from a traditional attitude indicator. >From what I understand, pitch information is only briefly displayed as an absolute angle and mostly is sustained by vertical airspeed information. Consequently, it would be possible, for example, to be flying slowly, pitch up without loosing altitude with the unit showing a level attitude. Maybe I'm too nervous, but if I was in clouds in this attitude I would want to know it. As for bank information, the TruTrak shows rate of change of bank angle, not absolute bank angle. So conceivably, one could be in a forward slip (not turning), but in a constant bank angle with the unit showing level flight. TruTrak says that the device is actually better/safer in the clouds than a conventional attitude inidicator. So my questions are: Do you like andd depend on your TruTrak ADI? Can the TruTrak entirely replace the traditional attitude indicator/horizon? Am I properly understanding how the pitch and bank display operates? --Jose ________________________________ Message 13 ____________________________________ Time: 01:17:55 PM PST US From: Harley Subject: Re: AeroElectric-List: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp Works OK with XP and Firefox 3 as well... Harley ------------------------------------------------------------------------ Tony Babb wrote: > > It works for me. I'm using Win2K with IE7. > > For more information: > www.vx-aviation.com > > > > Vernon, I tried to look at your website, but nothing displays. Is it > working? > ________________________________ Message 14 ____________________________________ Time: 01:21:42 PM PST US From: "Valovich, Paul" Subject: AeroElectric-List: Dual Comm Antenna Spacing RV-8A with 2 comm radios - SL30 and an ICOM. Two Comant bent whip antennas on the bottom aft of the wing, one on each side. Aft one is positioned just aft of forward antenna tip. One of my buddies says they're too close toget her - that transmit on one will fry the other. Is he correct? What is the a ccepted / minimum spacing? Paul Valovich N192NM Reserved - Again ________________________________ Message 15 ____________________________________ Time: 02:40:25 PM PST US Subject: RE: AeroElectric-List: Dual Comm Antenna Spacing From: Paul, I have two com antennas inside the fuselage about 12" apart. They perform very well together. Yours are on opposite wings. Comant say's 36" as general practice Take a read on their website. There are a few exceptions, but you should be safe. http://www.comant.com/htmls/guide2.html -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Valovich, Paul Sent: Monday, June 23, 2008 4:19 PM To: aeroelectric-list@matronics.com Subject: AeroElectric-List: Dual Comm Antenna Spacing RV-8A with 2 comm radios - SL30 and an ICOM. Two Comant bent whip antennas on the bottom aft of the wing, one on each side. Aft one is positioned just aft of forward antenna tip. One of my buddies says they're too close together - that transmit on one will fry the other. Is he correct? What is the accepted / minimum spacing? Paul Valovich N192NM Reserved - Again ________________________________ Message 16 ____________________________________ Time: 04:03:38 PM PST US Subject: AeroElectric-List: Re: Dimmer trick From: "N601RT" Carlos, My ADI is on a dimmer circuit with several NuLites and an internally lit Garmin GI-106A. The ADI was initially too bright relative to the other instruments. I moved the dimmer wire from the +12V dimmer input (pin 3) to the +24V dimmer input and found the 'balance' and tracking between the ADI illumination and the illumination of the other instruments on the circuit to be much better. This does require having max brightness during the day for reading the ADI display. Regards, Roy N601RT: CH601HDS, nose gear, Rotax 912ULS, All electric, IFR equipped, 990hrs Read this topic online here: http://forums.matronics.com/viewtopic.php?p=189445#189445 ________________________________ Message 17 ____________________________________ Time: 05:51:49 PM PST US From: "Joe" Subject: Re: AeroElectric-List: Contactor Diodes Dave, When battery power is removed from a coil by opening a switch, the coil now becomes a power source and tries to keep the current flowing through itself in same direction that it was flowing before the switch was opened. Current that leaves a source wants to return to that same source (but to the terminal of opposite polarity) by easiest path possible. Although the diode blocked current flow from the battery, the polarity of the current generated by the coil is such that the diode easily conducts it (as long as the voltage is above approximately 1 volt). The majority of the coil-generated current will find it much easier to travel through the short path of the diode to get back to the other end of the coil, rather than through the air between the opening contacts of the switch. The above events only last for a fraction of a second. It might be easier to understand if one uses a water analogy. Suppose there is a water pump instead of a battery, pipes instead of wires, coiled tubing instead of a contactor coil, valves instead of switches, and a check valve instead of a diode. If the pump were running and valves were suddenly closed on each side of the coil of tubing, the momentum of the water flowing through the coil of tubing would want to keep that water flowing in the same direction. The check valve would give the water an easy path to keep water flowing in the same direction from the outlet of the tubing back to the inlet of the tubing, much easier than trying to go through a closed valve. In a short time, the energy would be spent and the water would stop flowing. I hope that helps. Joe Gores ________________________________ Message 18 ____________________________________ Time: 07:21:21 PM PST US From: "Robert Feldtman" Subject: Re: AeroElectric-List: Contactor Diodes you must be a teacher! this is excellent bobf On 6/23/08, Joe wrote: > > Dave, > > When battery power is removed from a coil by opening a switch, the > coil now becomes a power source and tries to keep the current flowing > through itself in same direction that it was flowing before the switch was > opened. Current that leaves a source wants to return to that same source > (but to the terminal of opposite polarity) by easiest path possible. Although > the diode blocked current flow from the battery, the polarity of the current > generated by the coil is such that the diode easily conducts it (as long as > the voltage is above approximately 1 volt). The majority of the > coil-generated current will find it much easier to travel through the short > path of the diode to get back to the other end of the coil, rather than > through the air between the opening contacts of the switch. The above > events only last for a fraction of a second. > > It might be easier to understand if one uses a water analogy. Suppose > there is a water pump instead of a battery, pipes instead of wires, coiled > tubing instead of a contactor coil, valves instead of switches, and a check > valve instead of a diode. If the pump were running and valves were > suddenly closed on each side of the coil of tubing, the momentum of the > water flowing through the coil of tubing would want to keep that water > flowing in the same direction. The check valve would give the water an > easy path to keep water flowing in the same direction from the outlet of the > tubing back to the inlet of the tubing, much easier than trying to go > through a closed valve. In a short time, the energy would be spent and the > water would stop flowing. > > I hope that helps. > > Joe Gores > > * > > * > > ________________________________ Message 19 ____________________________________ Time: 09:29:10 PM PST US From: Joemotis@aol.com Subject: Re: AeroElectric-List: Contactor Diodes You win the internet! Great example. Thanks joe no archivos hombre!! **************Gas prices getting you down? Search AOL Autos for fuel-efficient used cars. (http://autos.aol.com/used?ncid=aolaut00050000000007) ________________________________ Message 20 ____________________________________ Time: 11:12:40 PM PST US From: "Vernon Little" Subject: RE: AeroElectric-List: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp Not sure what your situation is, but the only other complaint I had was when the user missed the dash "-" in the link. Try again, it looks like other users are connecting fine. Thanks, Vern -----Original Message ----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Harley Sent: June 23, 2008 1:16 PM Subject: Re: AeroElectric-List: Inverting the sense for warning tone controls/ audio mixer/ stereo music amp Works OK with XP and Firefox 3 as well... Harley _____ Tony Babb wrote: It works for me. I'm using Win2K with IE7. For more information: www.vx-aviation.com Vernon, I tried to look at your website, but nothing displays. Is it working? ------------------------------------------------------------------------------------- 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.