On 5/25/2011 2:25 PM, V G wrote: > On Wed, May 25, 2011 at 8:06 AM, Olin Lathropw= rote: > >> For power applications, the two main things to consider are power >> dissipation and how the part needs to be driven. FETs look more like a >> resistor when on, and bipolars more like a voltage source. > > I've seen you say this before, but I don't understand this. Could you ple= ase > explain this? Aren't they both like base/gate controlled variable resisto= rs? When fully on, a FET has a resistance - RdsON. When fully on, a Bipolar has a voltage drop - Vce(sat) Maybe better put - a FET is like a resistor, a Bipolar is like a diode. -forrest --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .