Re: Reversed Biased MOSFETS & BJT's?

"RogerN"
> 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?


** Mosfets have a diode from source to drain -  built in - so as soon as 
there is reverse voltage they conduct.

A power BJT will stand maybe 10 volts reverse collector emitter before 
conduction begins -  but you had better test a few samples before relying
on 
this.

However, by far you BEST option is to use polarised connectors on the 
charger and battery pack to PREVENT reverse connection.



....    Phil