AeroElectric-List Digest Archive

Wed 10/26/11


Total Messages Posted: 14



Today's Message Index:
----------------------
 
     1. 07:21 AM - Re: Transponder antennas (Robert L. Nuckolls, III)
     2. 08:00 AM - Re: Transponder antennas (Harley)
     3. 08:33 AM - Incandescent lamps in Wig-Wag systems (Robert L. Nuckolls, III)
     4. 09:07 AM - RAC RP3 LED Indicators (Bill S)
     5. 09:25 AM - Re: Incandescent lamps in Wig-Wag systems (David Lloyd)
     6. 09:32 AM - Altitude Encoder Pin Outs (Jerald Folkerts)
     7. 10:19 AM - Re: RAC RP3 LED Indicators (Robert L. Nuckolls, III)
     8. 10:39 AM - Re: Incandescent lamps in Wig-Wag systems (Robert L. Nuckolls, III)
     9. 11:33 AM - Re: Incandescent lamps in Wig-Wag systems (Robert L. Nuckolls, III)
    10. 11:39 AM - Portable Bench Test Battery (Robert L. Nuckolls, III)
    11. 11:43 AM - Portable Bench Test Battery (Robert L. Nuckolls, III)
    12. 02:05 PM - Z16 voltage concern (Les Goldner)
    13. 07:26 PM - Re: Z16 voltage concern (Robert L. Nuckolls, III)
    14. 11:45 PM - Re: Z16 voltage concern (Jay Hyde)
 
 
 


Message 1


  • INDEX
  • Back to Main INDEX
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:21:10 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Transponder antennas
    At 01:37 PM 10/25/2011, you wrote: Since there is functionally no difference between the two antennas, sure, you can have the "RST" unit, Bob...I'll use the TED antenna (it looks more professional!)...and fabricate a new ground plane plate for it. Actually, the pictures will suffice. Now you've got me wondering. If it was not from RST, then I have no idea where else I would have got that aluminum antenna from...it was on a shelf at my hangar with the parts that I did get from RST that I didn't use (nav antenna and some BNC connectors and cable)...and the octagon ground plane was with it. BTW...now that I've had it in my hand, the grommet is fiber, not rubber. Yeah, that makes sense. It needs to be mechanically rigid. I'll send the ground plane along with it...where do you want me to send them? Here's two pictures of the front and back of it that I just took a few minutes ago (I assembled it...the small parts all came in a small plastic bag...the ground plane was separate): I published a similar configuration in the 'Connection way back when. It would be interesting to know who made it. In any case, the pictures are great. I'll probably add them to the photo album on the website. What do you plan to do with it? I would have photographed it and then put it into the collection of curiosities . . . but I have plenty of those laying around! Bob . . .


    Message 2


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 08:00:55 AM PST US
    From: Harley <harley@AgelessWings.com>
    Subject: Re: Transponder antennas
    > Since there is functionally no difference between the two > antennas, sure, you can have the "RST" unit, Bob...I'll use the > TED antenna (it looks more professional!)...and fabricate a new > ground plane plate for it. > > Actually, the pictures will suffice. Well, then...if anyone else here wants it, just drop me a line. Just pay for the postage...I am talking about the one in the pictures, not the TED unit, which I will be using. Harley


    Message 3


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 08:33:54 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Incandescent lamps in Wig-Wag systems
    A few weeks ago I was called to task for some demonstrably sloppy data gathering when we were discussing inrush limiting on incandescent lamps used in wig-wag recognition systems. The plot I'd published at: http://www.aeroelectric.com/Pictures/Curves/Wig_Wag_Currents.jpg . . . was properly identified as somewhat 'fuzzy' and not properly supportive of some estimates of the cold start inrush values. I ran across my little po' boy's solid state switch yesterday so I drug it to the bench and set up the following experiment: http://aeroelectric.com/Pictures/Schematics/Test_Set-Up_Picture.jpg http://aeroelectric.com/Pictures/Schematics/Test_Set-Up_Schematic.jpg I ran some data plots with a 1 ohm resistor-load in place of the lamp. Here we observe the expected current flow plotted at scan speeds that will display 3-4 wig-wag cycles. http://www.aeroelectric.com/Pictures/Curves/1-OHM_250mS.jpg Then I zoomed in on an exemplar ON transition . . . http://www.aeroelectric.com/Pictures/Curves/1-OHM_50uS.jpg . . . and we see that the 'probe' connection is a tad bit over-damped as indicated by the rounding at the upper corner of the rise. I then replaced the load resistor with a 55w halogen head lamp bulb and produced this plot of wig-wag currents: http://www.aeroelectric.com/Pictures/Curves/55W%20WIGWAG.jpg Here we see the effects of lamp temperature on the inrush and running currents. At turn on, the lamp was cool enough to produce about a 9A spike. The measured current just before turn-off was on the order of 5A. Inrush current from a cold start is determined by total loop resistance of the wiring, battery source impedance, and lamp cold resistance. The lamp has a measured cold resistance of 145 milliohms. If driven by a zero-ohms source at 12v, the theoretical inrush would be 12/.134 = 83 amps. The slow sweep peek at a cold start in this test setup yielded the following trace: http://www.aeroelectric.com/Pictures/Curves/55W_COLD-START_1mS.jpg Here we see a measured inrush on the order of 42 amps. This suggests that wiring and battery resistances added another 140 milliohms or so to the loop resistance. Zooming in for a closer peek at the cold start . . . http://www.aeroelectric.com/Pictures/Curves/1-OHM_50uS.jpg we see the same 42A displayed value for peak current. Further, there is still more rounding of the plot as compared with the almost purely resistive plot cited above. Exploration of lamp behavior during turn-on could not be conducted with a mechanical switch or relay. Contact bounce during turn-on would badly contaminate the data. The solid state switch driven by a function generator suffers no such shortcomings. The closer look confirms that my original suppositions for inrush on the trashy trace were correct. The earlier plot was made with longer wires than for this experiment hence we saw a 32A cold start inrush as opposed to 42A in this case. It also confirms that the dynamics for rate of rise and peak currents are limited by system wiring (resistance and inductance) and there were no erroneous observations limited by oscilloscope sample rates. This experiment supports my original assertions that turn-on transitions during wig-wag operations are a small fraction (about 25%) of the initial cold-start value. Bob . . .


    Message 4


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 09:07:57 AM PST US
    From: "Bill S" <docyukon@ptcnet.net>
    Subject: RAC RP3 LED Indicators
    Can two or more rp3 indicators be paralleled to one POS 5 or POS12 position sensor? Thanks Doc


    Message 5


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 09:25:11 AM PST US
    From: "David Lloyd" <skywagon@charter.net>
    Subject: Re: Incandescent lamps in Wig-Wag systems
    Bob, Your further investigation of the halogen 55W inrush current is enlightening and hints at why the early failures. I am ignorant concerning "modern" filaments used in these brighter lamps. A start-up of 42 amps seems high for a design that nominally floats at 4 - 5 amps. I am wondering what that inrush thump does to a captured spring round, mechanical filament. There must a some mechanical jolting going on for those few msecs. When I observed the filament under a 6X magnifier, the filament windings appeared to have little spacing between turns. You could observe some spacing but, it was the same or less than the diameter of the filament wire. Possibly they have an alloy now that does not expand much from heat and magnetics of a huge initial inrush of current. David ___________________________________________________________ ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com> Sent: Wednesday, October 26, 2011 8:30 AM Subject: AeroElectric-List: Incandescent lamps in Wig-Wag systems > <nuckolls.bob@aeroelectric.com> > > A few weeks ago I was called to task for some > demonstrably sloppy data gathering when we were > discussing inrush limiting on incandescent lamps > used in wig-wag recognition systems. The plot I'd > published at: > > http://www.aeroelectric.com/Pictures/Curves/Wig_Wag_Currents.jpg > > . . . was properly identified as somewhat 'fuzzy' and > not properly supportive of some estimates of the cold > start inrush values. I ran across my little po' boy's > solid state switch yesterday so I drug it to the bench > and set up the following experiment: > > http://aeroelectric.com/Pictures/Schematics/Test_Set-Up_Picture.jpg > > http://aeroelectric.com/Pictures/Schematics/Test_Set-Up_Schematic.jpg > > I ran some data plots with a 1 ohm resistor-load in place > of the lamp. Here we observe the expected current flow > plotted at scan speeds that will display 3-4 wig-wag cycles. > > http://www.aeroelectric.com/Pictures/Curves/1-OHM_250mS.jpg > > Then I zoomed in on an exemplar ON transition . . . > > http://www.aeroelectric.com/Pictures/Curves/1-OHM_50uS.jpg > > . . . and we see that the 'probe' connection is a tad > bit over-damped as indicated by the rounding at the upper > corner of the rise. > > I then replaced the load resistor with a 55w halogen > head lamp bulb and produced this plot of wig-wag > currents: > > http://www.aeroelectric.com/Pictures/Curves/55W%20WIGWAG.jpg > > Here we see the effects of lamp temperature on the inrush > and running currents. At turn on, the lamp was cool enough > to produce about a 9A spike. The measured current just > before turn-off was on the order of 5A. > > Inrush current from a cold start is determined by total > loop resistance of the wiring, battery source impedance, > and lamp cold resistance. The lamp has a measured cold > resistance of 145 milliohms. If driven by a zero-ohms > source at 12v, the theoretical inrush would be > 12/.134 = 83 amps. The slow sweep peek at a cold start > in this test setup yielded the following trace: > > http://www.aeroelectric.com/Pictures/Curves/55W_COLD-START_1mS.jpg > > Here we see a measured inrush on the order of 42 amps. > This suggests that wiring and battery resistances added > another 140 milliohms or so to the loop resistance. > > Zooming in for a closer peek at the cold start . . . > > http://www.aeroelectric.com/Pictures/Curves/1-OHM_50uS.jpg > > we see the same 42A displayed value for peak current. > Further, there is still more rounding of the plot as > compared with the almost purely resistive plot cited > above. > > Exploration of lamp behavior during turn-on could not > be conducted with a mechanical switch or relay. Contact > bounce during turn-on would badly contaminate the data. > The solid state switch driven by a function generator > suffers no such shortcomings. > > The closer look confirms that my original suppositions > for inrush on the trashy trace were correct. The earlier > plot was made with longer wires than for this experiment > hence we saw a 32A cold start inrush as opposed to 42A > in this case. It also confirms that the dynamics for rate of > rise and peak currents are limited by system wiring > (resistance and inductance) and there were no erroneous > observations limited by oscilloscope sample rates. > > This experiment supports my original assertions that > turn-on transitions during wig-wag operations are a small > fraction (about 25%) of the initial cold-start value. > > > Bob . . . > > >


    Message 6


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 09:32:04 AM PST US
    From: "Jerald Folkerts" <jfolkerts1@gmail.com>
    Subject: Altitude Encoder Pin Outs
    I recently purchased a used II Morrow Apollo Altitude Encoder, model #428-2003. I haven't been able to find a diagram/description of the 15 pin connector on the back. Does anyone have a description, or are these standard pinouts? Thanks, Jerry Folkerts SR #093 www.mykitlog.com/jfolkerts/


    Message 7


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 10:19:23 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: RAC RP3 LED Indicators
    At 11:04 AM 10/26/2011, you wrote: > Can two or more rp3 indicators be paralleled to one POS > 5 or POS12 position sensor? Thanks Doc Not enough data to offer considered advice. Do these indicators have built in resistors? If so, they're designed to work on some voltage higher than the threshold voltage of the LED. In this case, they can probably be paralleled. If no internal resistors, then they're current operated devices and need to be wired in series. Bob . . .


    Message 8


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 10:39:27 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Incandescent lamps in Wig-Wag systems
    At 11:22 AM 10/26/2011, you wrote: > >Bob, >Your further investigation of the halogen 55W inrush current is >enlightening and hints at why the early failures. >I am ignorant concerning "modern" filaments used in these brighter lamps. I'm not sure there's much difference in modern vs. legacy tungsten filaments. Both lamps us the same material. The major differences are the surrounding gasses within the glass envelope that permit operation at higher temperatures. >A start-up of 42 amps seems high for a design that nominally floats >at 4 - 5 amps. I am wondering what that inrush thump does to a >captured spring round, mechanical filament. There must a some >mechanical jolting going on for those few msecs. If you wired your landing light system with say, 10AWG wire, you could get more than a 10X increase of inrush vs. running current. Yes, the thermal stresses during cold-start turn on are impressive. Power dissipated in the exemplar filament at cold start . . . W = R x I^2 .145 x 42 x 42 is 255 watts if you wired with short runs of fat wire that produced an 82A inrush we get .145 x 82 x 82 = 974 watts. Of course this tapers off rapidly. Referring to the 'fuzzy' plot http://www.aeroelectric.com/Pictures/Curves/Wig_Wag_Currents.jpg We see that it takes about 100 milliseconds for the max inrush value to fall to normal operating levels. But for the first 20 milliseconds or so, that little chunk of tungsten is being bullied rather severely. >When I observed the filament under a 6X magnifier, the filament >windings appeared to have little spacing between turns. You could >observe some spacing but, it was the same or less than the diameter >of the filament wire. > >Possibly they have an alloy now that does not expand much from heat >and magnetics of a huge initial inrush of current. I think it's mostly a rate of temperature rise combined with the manner in which conductors burn in two. If you hang a length of wire out in space and hit it with a current expected to burn it in two, it will open up close to the center of the span. This is because resistance goes up with temperature and material at the center of the span gets energy pumped into it both locally and from both sides. I.e. temperature AND resistance goes up fastest in the middle thus making it the most likely point to reach destructive temperatures. Evaporation of filament material causes localized increase in resistance. This aggravates the rate of rise for temperature during the inrush transient and causes failure to happen in the filament's weakest location. I believe there are two forces at work in the failure of lamps. Vibration while cold and d-temp/d-seconds rate during inrush. Keep-warm offers some mitigation of both effects . . . inrush limiting can only mitigate turn-on transients. Bob . . .


    Message 9


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:33:07 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Incandescent lamps in Wig-Wag systems
    <nuckolls.bob@aeroelectric.com> At 11:22 AM 10/26/2011, you wrote: > >A start-up of 42 amps seems high for a design that nominally floats >at 4 - 5 amps. I am wondering what that inrush thump does to a >captured spring round, mechanical filament. There must a some >mechanical jolting going on for those few msecs. I went back and got this plot http://www.aeroelectric.com/Pictures/Curves/55W_COLD-START_25mS.jpg This shows that current draw for lamp under examination in this test configuration goes from 44A down to 10A in about 37 mS. It probably takes another 150-200 mS to settle out on the steady state current measured at 5.2 amps. Bob . . .


    Message 10


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:39:14 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Portable Bench Test Battery
    As I was putting the morning's experiment tools away it occurred to me that many of you might find value in this tool. If you're pulling a battery out of your airplane because it no longer meets design goals for battery-only operations, it may well have lots of life in a work-bench based role. See: http://aeroelectric.com/Pictures/Tools/Test_Equipment/Bench-Test_Battery.jpg This particular battery was brand new about 10 years ago and placed into service as an instrumentation battery for stuff I was doing at Beech. Haven't cap-checked it lately but it still load tests at over 300 Amps for 15 seconds. Here you see how I bonded a breaker-switch on the top along with a 3/4" spaced banana jack set with JB-Weld. A handle was added by running three strands of 2" wide glass-reenforced strapping tape from side to side . . . bunching it up in the 'grip' area and wrapping with tape. This tool has seen service in many situations where I needed some 12-Volt snort with considerable load handling ability and/or capacity. Your choice of connectors and switch are optional as well as size of protection. If you use a generic switch, stick an in-line fuse holder in the wiring. You can select a plug in fuse from 3 to 30 amps . . . appropriate to the task at hand. Bob . . .


    Message 11


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:43:43 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Portable Bench Test Battery
    See: http://aeroelectric.com/Pictures/Tools/Test_Equipment/Bench-Test_Battery.jpg This particular battery was brand new about 10 years ago and placed into service as an instrumentation battery for stuff I was doing at Beech. Haven't cap-checked it lately but it still load tests at over 300 Amps for 15 seconds. Oh yeah, forgot to mention. This battery has been used to start numerous cars given the exposed jumper-cable- friendly posts. When not in use, it sets on a Battery Tender. Bob . . .


    Message 12


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 02:05:11 PM PST US
    From: "Les Goldner" <lgold@quantum-associates.com>
    Subject: Z16 voltage concern
    Robert, I used your Z16 drawing in my Rotax 912 powered Zenith aircraft when I built it three yours ago. It works great except for a low voltage problem from the get-go whenever the main power distribution bus is on without turning on the endurance bus. With the main bus only, I get about 12.5 volts on instruments attached to the endurance bus. With both buses set to "on" I get about 13.5 volts coming to these instruments. Of course this varies somewhat depending on whether the motor is on, with RPM, and with the state of battery charge, but the difference remains depending upon whether the endurance bus is on or off. Some of my instruments are sensitive to voltage so I have to leave the endurance buss on at all times. I have changes batteries and the Rotax voltage regulator but this situation remains. Is this normal or is there a problem that needs to be addressed? If there is a problem, can you suggest a fix? Thank you for your help, Les


    Message 13


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:26:17 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Z16 voltage concern
    At 03:59 PM 10/26/2011, you wrote: Robert, I used your Z16 drawing in my Rotax 912 powered Zenith aircraft when I built it three yours ago. It works great except for a low voltage problem from the get-go whenever the main power distribution bus is on without turning on the endurance bus. With the main bus only, I get about 12.5 volts on instruments attached to the endurance bus. With both buses set to "on" I get about 13.5 volts coming to these instruments. Of course this varies somewhat depending on whether the motor is on, with RPM, and with the state of battery charge, but the difference remains depending upon whether the endurance bus is on or off. Some of my instruments are sensitive to voltage so I have to leave the endurance buss on at all times. I have changes batteries and the Rotax voltage regulator but this situation remains. Is this normal or is there a problem that needs to be addressed? If there is a problem, can you suggest a fix? Thank you for your help, Have you conducted a load analysis? What's the expected load on the alternator with everything turned on? Does your engine have the external belt driven alternator . . . or just the built in? Since you referenced Z16, I presume it's the built in alternator. The built-in alternator is good for about 18A total. If the battery is not fully charged, it can soak up a large proportion of that 18A. You need to put a good charger/maintainer on the battery and make sure it is topped off. Start the engine and turn off every accessory with a switch. You can't get full output out of the alternator except at cruise: Emacs! This data plot is a real 'hedge' on reality. First a 5% tolerance. Next good at 20C. Finally, output at these loads may be as low as 13.5 volts. In other words, high enough to keep you from discharging the battery but not enough to charge it either. Hence, that excursion above 20A is a bit of whimsy seldom realized in real world utility. In your case, we first need to see if the alternator WILL charge a battery at 14.2 or a tad better if all the system loads are minimized if not OFF> Bob . . .


    Message 14


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:45:38 PM PST US
    From: "Jay Hyde" <jay@horriblehyde.com>
    Subject: Z16 voltage concern
    Hello Les, The problem comes from the diode between the Main Bus and the Endurance bus; the forward voltage drop across this diode leaves you with the lower voltage at the Endurance bus. When you put the alternate feed on to the Endurance bus you 'boost' boost the voltage because there is no diode in the alternate path. If you use a Schottkey diode instead of a normal diode between the Main and Endurance bus the Endurance bus voltage will be better as the forward voltage drop across a Schottkey is less than that of a normal diode, but you will always have a slightly lower voltage on the Endurance bus. Jay From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Les Goldner Sent: 26 October 2011 10:59 PM Subject: AeroElectric-List: Z16 voltage concern Robert, I used your Z16 drawing in my Rotax 912 powered Zenith aircraft when I built it three yours ago. It works great except for a low voltage problem from the get-go whenever the main power distribution bus is on without turning on the endurance bus. With the main bus only, I get about 12.5 volts on instruments attached to the endurance bus. With both buses set to "on" I get about 13.5 volts coming to these instruments. Of course this varies somewhat depending on whether the motor is on, with RPM, and with the state of battery charge, but the difference remains depending upon whether the endurance bus is on or off. Some of my instruments are sensitive to voltage so I have to leave the endurance buss on at all times. I have changes batteries and the Rotax voltage regulator but this situation remains. Is this normal or is there a problem that needs to be addressed? If there is a problem, can you suggest a fix? Thank you for your help, Les




    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
  • 7-Day List Browse
  •   http://www.matronics.com/browse/aeroelectric-list
  • Browse AeroElectric-List 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.

    -- Please support this service by making your Contribution today! --