On Thu, 28 Aug 2003 12:02:27 -0500, Don Foreman
wrote:

On Thu, 28 Aug 2003 06:59:19 -0700, Eric R Snow
wrote:

SNIP

For 12 watts a battery would be a lot simpler if perhaps not nearly as
much fun.




Not as much fun and not guaranteed to have power for the lights as
long as the motor is running. Besides, I don't want a big battery
pack. Now, don't tell me about reliability and how more things to
supply power just means more thing to go wrong .
ERS

I would much rather help you succeed than be a failure forecaster!

Have you thought about if you'll need voltage regulation, and if so
how you'll accomplish that?

You may want a motor with rated voltage higher than 12 volts. Most
outboards max out at about 5000 to 5500 RPM but you may want lights at
less than wide-open throttle. Small DCPM motors typically spin pretty
fast at rated voltage so they'd need to spin similarly fast to
generate rated voltage. However, a higher-voltage motor will produce
more volts per RPM because they have more turns on the windings. 90
volts is a common DCPM voltage, I don't think a 1-amp 90VDC motor
would be very big and it would make 12 volts at fairly low RPM.

I'm going to Ax-Man today to see what they have in motors.
The motor I tested that comes closest to what I want is 2.25 long and
1.5 dia.. At 10,000 rpm it was putting out 9 volts @ 1.5 amps. It was
$10.00 at H.F.. It came complete with a drill chuck, batteries,
charger and a drill motor case wrapped around it. For 8 bucks they
have one with a keyed chuck. If two were connected in series then spun
to 15,000 rpm max then with a cheap regulator the batteries could be
charged and the lights lit. Now, if a similar sized motor came along
with a higher voltage output so only one would be needed then that
would be great. I'm curious to see what Ax-Man has.
ERS