At 07:29 PM 11/10/97 -0500, you wrote:
>On Mon, 10 Nov 1997, Walter Markiw wrote:
>
>> >        What's the current? I would personally go with MOSFETs (thanks to
>> >all who helped me with this last month), because driving a MOSFET is
>> >pretty trivial, with one caveat: the load, looking into the gate is
>> >capacitive, so it draws virtually no current at steady state, but can draw
>> >(or sink) a much larger amount during turn-on and turn-off (when dI/dt is
>
>        A small mistake here -- dI(gate)/dt is proportional to
>dV(gate)/dt.


Don't you mean I(gate) is proportional to dV(gate)/dt?

For a cap. load:

Q=CV

differentiate both sides:

dQ/dt = C dV/dt

dQ/dt = I

therefore:

I = C dV/dt


I am curious about one thing: What are the major differences between IGBTs
and MOSFETS? Lower Rds(on)?

Sean

Sean Breheny,KA3YXM
Electrical Engineering Student