Philip Mac Duffie wrote: >Once upon a time I saw a overly complex 555 based ......snip This isn't exactly as you described, but it looks similar and has had some thought put into it. Try: http://www.hills2.u-net-dot-com/electron/eht3.htm A lot of components for an ignition coil driver, but then again, I've fried many a 555 attempting the same :-) hope this helps (c.c. emailed) Ed.