On Tue, Jan 25, 2011 at 8:01 PM, Dwayne Reid wrote= : > 1) the LEDs never turn off. =A0They always see 12V applied to them via D2= .. I wondered about that. I'm not sure how to fix that. Aren't they also being fed by D1, through R1? > 2) T3 not necessary. =A0Instead, connect the left side of R2 to T5c. Interesting. So in that case T4 functions as the inverter and prevents the two transistors from both being on? > 3) I really RP's circuit. =A0Why not give it a try? A few reasons. First off, I don't fully understand it, even with the excellent explanation someone posted. I'm working on it, but I'm not there yet. Second, I like this idea because if I thought it might be easier to also add a 12V PWM mode to this one. That said, on looking at RP's circuit again, I think if I added a transistor from the R1/D1 junction to ground, I should be able to PWM on the low side. I'm unsure what this would do to the flash circuit though. Thoughts? Josh --=20 A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. =A0 =A0 =A0 =A0 -Douglas Adams --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .