Re: Reversed Biased MOSFETS & BJT's?

On Sun, 12 Oct 2008 08:49:30 -0500, "RogerN" <regor@[EMAIL PROTECTED]
>
wrote:

>I'm working on a battery charger / discharger design.  There is always
the 
>possibility that someone will connect a battery reverse polarity.  I
don't 
>want this to destroy the charger.  I remember the stuff about correctly 
>biasing transistors but how will a BJT or MOSTES act if you have
Collector 
>Emitter or Drain Source reverse biased?  I'm trying to avoid diodes in
the 
>discharge circuit unless the are required as I want to be able to
dicharge 
>to 1V while measuring current and voltage.
>
>I tried this on simulation and it seems to work (not conduct) but I don't

>know if the simulation is realistic with reverse bias.  I can also get a
1A 
>diode to work at 500A in simulation.
>

Your model may not include the 'parasitic' diodes that normally exist
in these parts. If in doubt, add them externally in the simulation. 

Reverse battery protection at he output of a circuit is the same as
for the input. Googling should provide various suggestions.

RL