> Without going down the whole reverse engineering, desgn calculation > path, does someone have a simple, rule of thumb value for emitter > resistors to promote current sharing in paralleled bipolar transistors ? Hi Steve! How about .1 to .5 ohms? Basically, anything will work. The more resistance, the closer the current will be. Assuming -2.2 mV/degC, .1 ohm, 1 amp difference between the two transistors, the two transistors, that's over 40 degC difference in their junction temperatures. Hopefully the transistors share the same heatsink! Then the transistors will tend to track each other. Cheerful regards, Bob -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu