I missed the earlier thread. Where did you get these? I wired up some old Marx warning flashers with some I found. I got one from Circuitron, but I blew one of the transistors on it. I replaced the transistor, but I think it blew again. It had a problem with the LED bulbs I was using. The Circuitron boards were expensive too.
Hi George. Thanks for your interest. As was said, they are a DIY board that I put together and ordered boards using DipTrace. They are the result of a lot of help here on the forum from guys like Stan2004 and gunrunnerjohn, in a topic called Help Needed with a DipTrace circuit, or close to that.
The mosfets that were suggested were the perfect answer to switching more current than a couple of small leds use. Since starting this topic I tried it out with one 2.4 amp automotive bulb, and one 600 ma led bulb, as per the video below. Works well, no difference in flashing speed, and no trace of board or component heating, running at 13vdc. So all is well! The costs are $7.42 for all domestic parts and only $2 bucks for offshore boards and parts.
If there is interest I can post the Gerbers and the BOM for anyone interested in rolling their own?