------------------------------------------------------------------- -->> FREE Perl CGI scripts add WEB ACCESS to your POP email accounts! -->> Download today!! http://www.adjeweb.com ------------------------------------------------------------------- You are also absolutely correct. ---------- D. Yates piclist@nerdulator.net -------- Original Message -------- =3D=3D> From: Olin Lathrop =3D=3D> Date: Sat, 29 Nov 2003 09:02:08 -0500 D. Yates wrote: > I'd recommend a 2N3904 in a common-emitter=20 arrangement, with a > 1k resistor connecting the base to the PIC's=20 output. This should be > good up to ~200mA output, But the OP specifically said 300mA. > if you need more swap it out for a power > transistor like a=20 TIP120. I believe the TIP120 has a built in > reverse diode, so that=20 would reduce part count to 2 (resistor, > transistor). No, the diode is in the wrong place. The diode must be accross the=20 relay coil, not the transistor. *****************************************************************=20 Embed Inc, embedded system specialists in Littleton Massachusetts=20 (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out=20 subtopics (like ads or off topics) for you. See=20 http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics