I have found that the PIC is very reliable and tolernat to noice. BUT if you don't have the 0.01 myfarad capacitor across it's Vcc/Vdd, it is very sensitive. In your case maybe try«0.1 AND 1000pF instead. Close to the chip. Sven -----Ursprungligt meddelande----- FrŚn: Peter Tran Till: PICLIST@MITVMA.MIT.EDU Datum: den 7 april 1999 16:12 €mne: Relay problem > Whenever the 5V output from PIC is applied to relay, the microprocessor >will run unexpectedly. If I put relay in a separated board, it's OK. I think >the problem is the noise from the inductance of relay. Can anyone tell me >how to eliminate this problem? Thank you. > >________________________________________________________ >NetZero - We believe in a FREE Internet. Shouldn't you? >Get your FREE Internet Access and Email at >http://www.netzero.net/download.html >