At 03:52 PM 1/4/01 -0200, you wrote: >Hi. >I tryed to use PIC16C621A, RA4 as output, open drain. I put a 10K resistor >to Vcc and the base of a npn transistor in RA4 to drive a relay (relay >conected on colector with diode self induction protection, and emitter to >zero). Do you have a resistor between RA4 and the base? If not, put one in. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.