800ma current regulator

colin55 said:

Actually build the circuit and let me know the current reading.

Click to expand...

**broken link removed**
The .asc is accurate except for a filter cap or 2 and another inductor on the input power line and the power transistor for the Laptop power supply.
I'll power it up and put my scope, DSO2150, on it later today and take some screen shots to add to my webshots album for you. It now runs just over 20kHz and adding the 12V regulator for the SE555 seems to have helped, I now get good clean square waves out and with a 7 ohm load, I still had over 18 volts out, I'll take better notes when I power it up. Are you using something like this also.
Kinarfi

PS. Any one care to make an educated guess as to the rating of the amber colored inductors?

They look a lot like some 220uh @ 1 amp ones I have used.

That's probably why they are getting hot when I'm pull 3 amps out of the circuit. I replaced some of the photos to identify what the scope shot are and added the schematic to **broken link removed** . Looks like a successful design.
Kinarfi

after playing with this circuit and testing, this is what I finished with, the LM317 and Emitter following transistor are on the same heat sink and seem to be the only thing getting quite warm, so I added a fan and tucked the whole thing under the dash as the finished unit.