I believe there were plans for an ESC published in Model Aviation, authored by Bob Kopski. This was more than a year ago as I recall. If you're an AMA member, you can search the MA archives.
Randy
I don't remember where I saw it but RCM or MAN had plans for an ESC. I
> just had great success building an Onboard Glow Driver from RCM plans
> and I am looking for an another electronics project. Now that building
> a PC board doesn't scare me the world has gotten a little bigger. If
> somebody remembers what issue it was in please let me know. In fact I
> think the plans appeared in a second issuse with an improvement. > Thanks
>
> ERK