I have an application like this. The SCR is a triggering device, which does not turn off after it turns on. This characteristic is useful in certain situations. I have one where the SCR crowbars a coil which MUST stay off after a certain time, no matter what. No matter whether the PIC hangs, reboots, gets hit by a brownout, and so on. In quantities a TO-92 SCR will cost you US$0.06 to 0.10, whereas a 2n2222 will cost you about a penny, so most people don't use an SCR unless it is really needed. --Lawrence Lile ----- Original Message ----- From: "Shawn Yates" To: Sent: Tuesday, February 19, 2002 8:47 AM Subject: [EE]: SCV vs Transistor > I know this is a basic question, but I need to ask it. > > I have always used a transistor driven by the pin of a PIC to turn on and > off high current devices (relays, buzzers whatever). I saw a design where > someone was using an SCR. > > Is there any operational difference when the application is switching not > amplifying? > Is there a signifigant cost difference? > > What I am getting at is why would one use and SCR instead of a transistor. > They are even in the same TO package. > > Any input appreciated. > > Shawn > > -- > 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