Dropping voltage with diodes.

[soldar]

I'm not entirely sure on how much voltage to drop.

You experiment, you tweak, that's the whole fun of it. My builds are rarely entirely "finished" as I am always tweaking here and there... or just building a replacement. That's how you learn and get the feel of the ropes.

[langwadt]

how much capacitance you have? with 10000uF 26V peak is barely enough with no resistance and 10A

[davelectronic]

Yes I guess that's what I will be doing. So long as I don't blow things up in the process. The capacitance I'm using is 2 X 10000uf 63 volt electrolytic capacitors. That should be ok for 10 Amps at 13.80 volts. I am tempted to remove secondary windings, but don't want to mess up a perfectly good toroidal transformer. If it had a single winding, I probably would have done it by now. But twin secondary windings is a bit more daunting.