---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 07/18/04: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:58 PM - Re: Fw: Preflight Check List Item - 0.8V (Robert L. Nuckolls, III) 2. 08:19 PM - My Visio 2000 Stencil (Chad Robinson) ________________________________ Message 1 _____________________________________ Time: 02:58:02 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Fw: Preflight Check List Item - 0.8V --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:17 PM 7/17/2004 -0600, you wrote: >--> AeroElectric-List message posted by: "Rick Fogerson" > >Do not archive ----- Original Message ----- >From: Rick Fogerson >To: aeroelectric-list@matronics.com >Subject: Preflight Check List Item - 0.8V > > >Hi Bob, >There was a preflight item you recommended I check on my RV 6A that had to >do with 0.8 Volts and the essential bus. It's been 5 years since I've >owned the airplane. Is the test still recommended and if it is could you >refresh my memory on how the test was done and what it accomplished. Yes it is. If you have a diode isolated e-bus, then normal operating voltage for the e-bus is 0.6 to 1.0 volts lower than the main bus due to diode drop in a standard silicon junction diode like those illustrated and recommended in drawings found on the website. During pre-flight, it's recommended that you use a comm transceiver on the e-bus powered through the E-BUS ALT FEED (with the DC PWR MASTER - OFF) to get ATIS and or clearance delivery. If you have a voltmeter on the e-bus (also recommended) it will be reading present battery voltage. Compare this reading with reading for known good battery . . . this is a good preliminary check of battery condition. After engine is started, you can check the voltmeter again to see that the alternator has picked up the system . . . and it should be reading 14.0 to 14.5 volts. Turn the E-BUS alternate feed switch OFF and voltmeter should drop to perhaps as low as 13.0 volts depending on how much 'stuff' is on your e-bus. This sequence of switch operations shows that the diode is not shorted. If you'd like to reduce this voltage drop to something on the order of 0.5 to 0.7 volts, you can use what is known as a Schottky diode to replace the bridge rectifier depicted in my drawings. The rectifier was chosen not because of its electrical characteristics but its mechanical characteristics. Very user friendly mounting and wiring. I've had a couple of builders replace the e-bus isolation diode with a relay driven from a LV WARN/Ignition Battery Management Module . . . this drives the voltage drop down still further but replaces a lifetime solid state part with a relay (ugh!) and drives up parts count. Bob . . . --- ________________________________ Message 2 _____________________________________ Time: 08:19:15 PM PST US From: Chad Robinson Subject: AeroElectric-List: My Visio 2000 Stencil --> AeroElectric-List message posted by: Chad Robinson Hello all, I've received numerous requests in the past few days for my Visio stencil of the AeroElectric symbols. To anybody that may be looking for this file, please drop by http://www.lucubration.com/aero and you can download the file from there. I ask only that you recognize Bob Nuckolls' original efforts in creating these symbols in AutoCAD, and that if you make changes to the stencil that you recontribute them so I can post updated versions for everybody's benefit. A few comments: 1. To use the stencil you need any edition of Visio 2000 or higher. Save the stencil somewhere you can find it. Open Visio, create a new drawing, and click File->Open Stencil. Browse for where you saved the file and select it. Then drag symbols to your drawing and use the dynamic wire connector to draw wires. 2. You can adjust the thickness of wires and add labels to indicate their wire sizes. For an example of this, see my diagram in Chapter 22 of the "Orion" section of my site. 3. When you save and close your drawing, then re-open it, Visio should find the stencil again as long as you haven't moved it. 4. Some of the symbols aren't quite perfect, especially with respect to the text labels. Sometimes you have to click once and start typing to change a label, and sometimes you have to click twice (but NOT double-click, wait a second between clicks). For an example of this, see the battery or fuse symbols, or the switches. Regards, Chad