In a message dated 3/11/0 14:59:54, you wrote:
Ernesto Sanchez wrote:
Here's a site full of ideas for the home built aircraft electrical system:
http://www.aeroelectric.com/
http://www.aeroelectric.com/articles.html
If one is going to depend on a backup battery, I would suggest a periodic
(monthly? quarterly?) load test of the backup battery
And this link shows how to test a battery:
http://www.aeroelectric.com/articles/battest.pdf
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Wschertz@aol.com wrote:
The Aeroelectric Connection is a wealth of information for builders. It is
published by Bob Nuckols, in perusing my hard copy, It occurred to me that a
PM alternator might be a suitable device for backup -- in the following sense.
1. A conventional alternator belt driven for the main load.
2. The problem with a second alternator, is will the belt breaking on the
first cause the loss of the second?, etc.
3. What we want, I believe is a second alternator that is driven by a
different means -- i.e. direct drive or some such.
Since this group is now designing and building a variable pitch prop!!,
making a built in alternator should be a piece of cake. :-)
Consider a specially designed flywheel, with magnets secured on the inside
lip of the circumference. If you now put stationary poles with a single
heavy winding of a few turns, it will generate a voltage and current. A
coording to Aeroelectric, that is the design of the PM alternator. No
brushes, generates voltage proportional to rpm, and requires a special
regulator.
This would have no belts to break, could be designed to power the essential
buss which would include injection system, fuel pumps, and ignition. The
main load would be carried by the regular alternator, the PM alternator might
be designed only to put out the 8-12 amps required for emergency use. It
also could be built into the PSRU, so it would not steal space from the
under-cowl realestate.
Bill Schertz
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