This ASCII art apparently contains TAB characters, and is (like most attempts) totally unintelligible without saving it off and manipulating it. If (by some chance) it Doesn't contain tabs, then it;s been compromised in some other way by the cut/paste process. Use characters if you want someone to spend the time to look at your diagrams. It will save everyone a lot of time. Jim ----- Original Message ----- From: "Olin Lathrop" To: Sent: Thursday, October 02, 2003 12:49 PM Subject: Re: [PIC]:High Voltage problems help > > PIC16F628 > > ______ > > | | > > | | > > LED | | > > | | | > > gnd___|/|______|b2 | > > |\| _____|b3 | 5V > > | | |______| | > > | | > > | B|/ C > > |_______________| TIP42C > > |\ E ||c________1 > > |_______________c||c > > c||c > > c||c > > c||c > > | c_________2 > > -- -- > > - - > > - > > You need a diode from ground to the emitter of the transistor (anode to > ground, cathode to emitter). The transformer primary is an inductor, and > will try to make very high voltages if you try to stop the current > suddenly. The negative spike is probably causing considerable current to > flow thru the BE junction, then thru the protection diode in the PIC. > This can have all kinds of bad an unpredictable effects. > > > ***************************************************************** > 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