Re: BruceDP's Blazer goes hybrid

[Lee Hart <leeahart@earthlink.net>]

PETER VANDERWAL wrote:
> Is this a tested efficiency for the V-belt or one of your guestimates?

It was the efficiency of that particular v-belt and that particular
setup. Physically, I had a Corvair generator and the alternator under
test, with the v-belt running between their stock pulleys. I had
characterized the generators for various voltages and loads (with two
identical generators coupled). Running the generator with no belt gives
its no-load losses. Hooking up two such generators should double the
loss; any additional increase is the v-belt loss.

Likewise, the v-belt loss under load could be estimated by putting the
generator under load, and comparing power out and power in. As I recall,
belt loss was fairly constant regardless of load, and directly
proportional to rpm.

While I don't still have the old data, I don't think 90% efficiency is
at all unreasonable for a fully loaded v-belt. I know the Berg Pow-R-Vee
belts we used last year on the kids' EV race car were using less than 50
watts; motor current went from 12v at 2 amps with no belt to 12v at 5
amps with the belt on but the wheel in the air. And during the race we
were running in excess of 30 amps without it slipping.
-- 
Lee A. Hart                     Ring the bells that still can ring
4209 France Ave. N.             Forget your perfect offering
Robbinsdale, MN 55422 USA       There is a crack in everything
(612) 533-3226                  That's how the light gets in
<leeahart@earthlink.net>                Leonard Cohen