At 02:17 PM 4/1/2007, Peter P. wrote: >A pic chosen correctly usually has enough spare pins to use 2 or 3 in parallel >to drive such a small load reliably. I do NOT intend to start a flame-fest of any sort, but I'm afraid that I tend to snicker loudly when reading the above statement. Most PICs used in any kind of volume production don't have any spare pins. That's *MY* definition of a correctly-chosen device. That most often matches my customer's desires (or explicit instruction) as well. As someone else mentioned, I use cheap BJT's driving relays that operate from a different power supply rail than the PIC. This lets me use the least possible cost power supply for the PIC (also the most reliable). Said PIC power supply also completely avoids the lock-up conditions I've mentioned many times in the past where a PIC can lock up completely if its supply voltage drops down to the 0.5V - 0.7V range. I do that by ensuring that PIC Vdd line goes completely to 0V when power is removed. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 22 years of Engineering Innovation (1984 - 2006) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist