Got an old bike with a 6v system; replaced the selenium rectifier with a silicon one but an extra .4 volt of charging voltage might be helpful. Are there germanium diodes out there in the 10-20 amp range? Alternator is rated 6V 50W at 5k rpm.
High current germanium diodes?
Jun 17, 2008
11 Replies
A FET rectifier?
Schottky diodes are a lot more common in that size range and have about the same forward drop. They have quite a bit of reverse leakage, though.
For example:
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Regards,
John Popelish
Yup.
As would a germanium diode, or selenium, for that matter.
There are bazillions of Schottky types in that current range, so finding one should be easy.
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
True.
However, the generator system on older bikes usually behave like current sources, the voltage regulator (if at all present) is a big honking zener or zener / thyristor combination. Forward voltage drop may not be that important.
- René
"René"
** The OP is nuts.The forward drop of the selenium diodes in the old bridge is very likely MORE than that of a silicon equivalent at a current of 10 amps.
Plus it really don't matter at all for battery charging, for the obvious reason you gave.
.... Phil
I may have a few germanium ones in my "junk box." They are old, circa
60's, but may do the job for you. If you're interested, reply to this group and I'll send you one gratis. In return do someone else a favor.Al
Are you running anything but lights? They'll work on AC, you know. :-) (well, incandescents will. ;-) )
Good Luck! Rich
You have 10-20 amp GERMANIUM diodes?????!!!!?!?!?!?????
You MUST post pictures!
Thanks, Rich
Sure, I do too. I don't have many (only two), but I know a guy with buckets. He recently made a linear amplifier with them. [1]
Tim
[1] For those who haven't noticed, a germanium power transistor is composed of *two* diodes. ;-)
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
Everything is (now) LED except the main and dipped beams.
Standard 6 volt auto stuff is not that bright, and especially so when you are sitting at a stop, engine idling. I suspect that charging does not begin until 2500 revs or so; would like to drop that down by as much as possible - hence the thought of eliminating as much voltage drop (and current draw) as possible.
Oh, Boo. That was a cheap trick! ;-)
Cheers! Rich
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