Good day to all. I'm working on a project where I need to be able to turn OFF a relay=20 that is controlling AC Mains voltage at a precise point on the AC=20 waveform. The incoming AC is either 120 or 240Vac. Someone else had done a previous incarnation of this project and they=20 used a standard electro-mechanical relay. They compensated for the=20 release time of the relay with an adjustable timer. I'm leaning in the direction of using a pair of decent-sized MOSFETS=20 back-to-back with a photo-voltaic opto supplying gate drive and=20 another opto-isolator to either interrupt or short the gate drive to=20 the MOSFETS. This should give me sub-millisecond response and=20 eliminate the need for manually adjusting a timer. Digikey has a few photo-voltaic parts available and I'm just=20 automatically selecting one that has sufficient output voltage (8V)=20 and the maximum available output current (40uA) - its a Toshiba=20 TLP191BF. They also offer a 20uA version (TLP190BU) for a dollar less. Before I actually go and order these, I thought that I'd ask the=20 collected wisdom of the PIClist to see if there is something else=20 that I should be looking at. I'm not adverse to using something like a photo-MOS SSR instead of=20 rolling my own but I haven't found anything on Digikey that has a=20 decent current rating. This is currently only a one-off project but there is a possibility=20 that the customer may decide to roll these out to other=20 locations. That would bring the quantity up to perhaps a dozen or so. I'm also on the hunt for decent N-channel MOSFETs. Most of my old=20 standbys are Vgs to 10V minimum - the logic-level MOSFETs that I use=20 are only good up to 60V or so. I need a minimum 8A, 400V rating. I do see that Digikey shows that one of my old standbys (IRF840) is=20 shown as having a logic-level gate threshold - I need check that=20 because I was darned sure that is one of those parts wanting minimum=20 of 10V gate drive. But Digikey also shows part numbers that I=20 recognize from Fairchild and ST Micro, as well as some from somebody=20 whom I've never seen before: "Alpha & Omega Semiconductor Inc". Anyway, I'm about to order one of these parts but thought that I'd=20 also ask if anyone has any favorites. Many thanks! dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .