Sean Breheny wrote:
> 
> Ok, I've got to ask:
> 
> Can someone please explain why a resistor is needed and how it could matter
> where it was placed?
> 
> I could see that the resistor will limit the current which is charging up
> the gate,but how this would be likely to hurt either the PIC or the FET I
> don't really understand.
> 
> Thanks,
> 
> Sean

The instantaneous current drawn by the gate is very high, 
because it is a cap you are charging. 

As a rule of thumb, the smaller the cap, the lower the 
self-inductance, and the higher the peak current.

If you look in your PIC data sheets, you will find a 
well-hidden spec that says you shouldn't connect more than 
50pF (or was it 25pF?) *directly* on an output. A MOSFET 
can be several hundred (help me here, guys) pF.

Maybe you get away with it, maybe you don't.

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