Author Options:

How do I use MOSFET's for switching? Answered

I've been confused about this for a while now. I know how to use bipolar transistors(2N3904), but not MOSFET's. I've got one of these.

1 Replies

gmoonBest Answer (author)2009-03-03

Those have some fairly large voltage/current capabilities. Here's a page with good info about MOSFET switches.

Some thoughts about the difference between bipolar and Mosfets:

--Unlike bipolar transistors, Mosfets are voltage controlled. With a bipolar trans. switch being current controlled, the base resistor needs to be carefully calculated according to the amount of current being switched.

Not so with a MOSFET. Just apply enough voltage to the gate and the switch operates.

-- Because they are voltage controlled, MOSFETs have a very high input impedance, so just about anything can drive 'em.

Select as Best AnswerUndo Best Answer