MIKE ROSS wrote in a message to Greg Mayman:

 MR> "Greg Mayman" bravely wrote to "Roy J.
Tellason" (07 Sep 03 
 MR> 08:18:00)  --- on the heady topic of "VEHICLE LED'S"

 RJT> I wasn't aware of that.  Ok,  a schottky diode (lower voltage drop)

 GM> Or four diodes for a bridge which still gives a minimum of 2
 GM> diode drops on each half cycle. Thats about 2 x 0.5v = 1 volt. In
 GM> a total of 6v, that's a lot!

 MR> SCR's or transistors can be used instead of the rectifiers as they
 MR> have a much lower saturation voltage than a rectifier's forward
 MR> voltage. 

I wonder about that...

An SCR,  maybe.  A transistor?  I dunno.  A few years back I acquired a few
of these transistors in stud-mount packages,  that seem to be capable of
carrying a *lot* of amperage,  if properly heat-sinked.  And I was thinking
about using them in an automotive application,  more precisely to control
the charging or not of an auxiliary battery.  I've never sat down and
worked out the details, though.

But using them in place of rectifiers?  Normally the collector of a
transistor would be reverse-biased.  Then you switch polarities and it's
forward-biased?  I don't see how that's going to work real well.

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