---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 07/09/09: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:58 AM - Re: Altitude Encoder Readout (Joe) 2. 07:01 AM - Re: Re: Electrical Problem (Robert L. Nuckolls, III) 3. 07:20 AM - Re: Switch wiring conundrum (Robert L. Nuckolls, III) 4. 07:46 AM - Re: Icom A-210 intercom (Robert L. Nuckolls, III) 5. 07:55 AM - Re: Altitude Encoder Readout (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:58:19 AM PST US From: "Joe" Subject: Re: AeroElectric-List: Altitude Encoder Readout Larry Sharratt, I purchased the kit and built it and it works great. I doubt that the kit is available now but it would not hurt to ask. The name of the company was Airpar. Contact: Fred N Wimberly (703) 979-2483 PO Box 2755 617 21st St S Arlington, VA 22202-2732 I still have the construction manual and parts list. However, this will not do you much good without the PROM, the "brains" of the kit. The PROM must be programmed with the gray code, not an easy task (beyond my capability). If you really want to build an Altitude Encoder Read-Out and Fred Wimberly can not help, then perhaps a knowledgeable person on the AeroElectric website can help. Joe Gores ________________________________ Message 2 _____________________________________ Time: 07:01:42 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Electrical Problem At 04:06 PM 7/5/2009, you wrote: >Joe, > >I instruct in C172s with G1000s and that happens >on a regular basis. I dont think its really a >problem, it basically means the battery is fully >charged and at low RPMs its actually supplying >a few electrons more than the alternator. As >long as it goes away as soon as the RPMs come >up, I dont consider it an issue. Hopefully Bob will confirm It's a good hypothesis but would be confirmed by seeing the bus voltage fall below that value at which the battery will deliver significant energy, i.e. 13 volts. Back when ALL our cars were fitted with generators and most were fitted with battery ammeters, it was quite common to see the battery ammeter go into the discharge zone at curb idle . . . especially at night with lights and perhaps heater blowers turned on too. As soon as the car began moving, generator speeds would be sufficient to pick up all vehicle loads and the battery ammeter might even show a short duration "charge" transient as energy withdrawn from the battery at the last stop light was replaced. Ideally, after some significant interval of driving, the battery becomes fully charged and the battery ammeter needle assumes the "all is well" position very close to zero with a slight + bias. These same battery ammeters were never fitted with zero adjusters. Therefore it is possible that some devices would have different presentations for the "all is well" condition . . . they might even have a slight - (discharge) presentation. Until one conducts a no-wires-inside-the- hall-sensor experiment, the systems zero-current presentation is not known. Alternators were praised for their ability to maintain system voltage at or above battery discharge thresholds. So unless the bus voltage sags at idle due to ship's loads exceeding alternator capability at that RPM, then ammeter offset errors are suspected. This is one of the "problems" with integrating modern instrumentation technology into our airplanes. System readings that used to be presented to us by some fat needle on a tiny gage setting inside the green arc have been replaced with digits and decimal points. Unless those new instruments are favored with offset and scale factor calibration adjustments, then it's possible that their presentations could be sufficiently in error as to raise concerns. The way to resolve the issues is with comparative measurements against other instruments of known characeristics. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 3 _____________________________________ Time: 07:20:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Switch wiring conundrum At 11:25 PM 7/4/2009, you wrote: >Thanks to everyone for their thoughts. > >I "bit the bullet" and celebrated the 4th of July by spending a >delightful 5 hours under my instrument panel moving components / >rewiring / etc to shoe-horn in room for another switch -- which got >in there with 0.05" to spare. God then smiled on me & miraculously >there were even two new 2-3 switches squirreled away in the back of >the tool chest to allow me to directly replace the old 2-10. I think this is a good move my friend. In about a year, I'll be able to share the unfortunate details on an electrical system wherein the system designer took ingredients for biscuits, bread, hot cereal, and dumplings and stirred them into a new product that turned out to be less than palatable . . . and was in fact hazardous to health. It's in our best interests to first consider the manufacturer's instructions for integrating any critical components into an airplane. But it does not automatically follow that the manufacturer of a product is well versed in the art of failure mode effects analysis and design for failure tolerance. We should strive for the lightest, least expensive and least numbers of parts that minimize the need for pilot attention and intervention. I.e. the elegant solution. EVERY design is fair game for critical review. There's no such thing as a SAFE airplane, automobile, handgun or skateboard. There are considerations of design, installation, operation and environment that always yield to logical incorporation of simple-ideas into minimum risk recipes for success. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 4 _____________________________________ Time: 07:46:52 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Icom A-210 intercom At 11:09 PM 7/4/2009, you wrote: > > >Hi >speaking of intercoms, I just bought a new Icom 210 and want to put >it into my 2 seater. Does the 2 place VOX system work OK should I >have a seperate 2 place intercom. >I just want to be able to talk to my pax, TX from either position >and have an MP3 input. to both.. I think the A210 shares an intercom feature with many other compact comm radios like the Microair, X760, etc. The intercom is a "hot mike" system using the radios side-tone circuits that are energized with a push-to-talk button. I.e., with the intercom button pressed, both individuals hear each other and themselves speak. Unless the noise cancelling capability of the headset microphones is quite good, you would not want to leave the system in the "intercom hot" condition all the time. You'd get tired of listening to the cabin noise (or even hearing the passenger chew his/her gum). I've flown airplanes with PTT intercoms and personally, like them. It cuts down on idle chatter (due to the inconvenience of having to operated the button), and eliminates the VOX setting creep induced by changes in cabin noise levels. Most folks don't like this feature . . . I note that I didn't even show the PTT intercom button to pin 10 in my wiring diagrams. I'll suggest you give it a try. You can always add a VOX based intercom later. Your music system can be injected to one of the aux audio input pins C, D or 3. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 5 _____________________________________ Time: 07:55:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Altitude Encoder Readout At 08:55 AM 7/9/2009, you wrote: >Larry Sharratt, > >I purchased the kit and built it and it works great. I doubt that >the kit is available now but it would not hurt to ask. The name of >the company was Airpar. Contact: >Fred N Wimberly (703) 979-2483 >PO Box 2755 >617 21st St S >Arlington, VA 22202-2732 > >I still have the construction manual and parts list. However, this >will not do you much good without the PROM, the "brains" of the >kit. The PROM must be programmed with the gray code, not an easy >task (beyond my capability). If you really want to build an >Altitude Encoder Read-Out and Fred Wimberly can not help, then >perhaps a knowledgeable person on the AeroElectric website can help. I recall seeing various display projects over the years but was unable to "put my hands" on one quickly. There IS an interesting product designed by a friend of mine that reads the output of your transponder's reply burst. See: http://www.airsport-corp.com/ Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ------------------------------------------------------------------------------------- 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.