If you just fit a diode it will stop the TX resetting and cause it to saturate. you either need to put a snubber across the the Transistor or zenner + diode Richard ----- Original Message ----- From: "Olin Lathrop" To: Sent: Thursday, October 02, 2003 8:54 PM Subject: Re: [PIC]:High Voltage problems help > > Try running the transistor in common collector mode. > > Actually that's "common emitter". > > > - Connect transistor collector to OTHER end of primary. > > - Connect +5v to end of primary where ground is now. > > - Add a drive resistor from PIC pin to base - say 1k to start. > > > > Circuit now obeys the laws of physics. > > All circuits obey the laws of physics. However this one will still have a > problem without a diode from the collector to the +5V supply. > > > ***************************************************************** > Embed Inc, embedded system specialists in Littleton Massachusetts > (978) 742-9014, http://www.embedinc.com > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body