The solution proposed in this is really interesting for a project I'm on. Placing the SCR inside a full wave bridge is a neat trick. In this arrangement, the full wave bridge obviously has to handle the dfull load current of the load. What about the load on the SCR? Is it also the full load current, or something larger? -----Original Message----- From: Peter van Hoof To: PICLIST@MITVMA.MIT.EDU Date: Thursday, May 13, 1999 6:14 PM Subject: Re: Driving Back to Back SCR's from PIC or Where do I Find a Cheap Triac >-----Original Message----- >From: Jim Ruxton >To: PICLIST@MITVMA.MIT.EDU >Date: Thursday, May 13, 1999 12:20 PM >Subject: Driving Back to Back SCR's from PIC or Where do I Find a Cheap >Triac > > >>Hi Everyone, >> >> I'm trying to figure out how to drive 2 inverse parallel SCRs. From a >>PIC to control a full wave AC load. I am using a cheap and dirty non >>isolated power supply so my pic ground is sitting at neutral. Driving >>the one SCR that has its Cathode on the neutral line is no problem but >>driving the one that has its' Anode attached to neutral is the problem. >>I would use a triac but can't find one as cheap as the two SCRs. If any >>one knows where to get a cheap sensitive gate triac in a TO92 package >>for about 8 cents in quantity of 250K I'd love to hear about it or knows >>how to drive a full wave AC. load with one SCR from a PIC using a >>nonisolated supply , even better. >>Thanks >>Jim >> >>------| |--- > > >how about this solution >http://www.vertonet.com/members/pvh/scr.pdf i'm also ascii art impaired but >can use drawing software > >basicaly a scr in a full wave bridge in series with the load >get power for the pic from the other side of the load with diode, cap and >resistor in series. > > >Peter