Quote: Originally Posted by djmickyg
im having some trubble with the trasistor..
i got the black plastic half circle type not the metal can, its still a 2n222a but..
i cant get it to work
if i hook it up the way explained in the early post i get 4.5 v out the emitter
with 12V in the collector and the serial port in the base which puts out 5-6v
should there be this much of a voltage drop?
EDIT: this is the pins i used
Emitter is always a diode drop lower than the base when using a transistor in emitter-follower configuration like this. However, most serial ports swing -12v to +12v. It sounds like your serial port doesn't quite manage this, so you don't get the full voltage from the emitter follower. You'll be needing a better transistor circuit design. I'm thinking PNP open collector and flip the DTR line.
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