Do you have any problems with ignition or other noise on the power supply?

>
> It's a DC-DC converter I made myself. Nominal 12 volts in. +5, +12, and -12
> out, as well as PowerGood signal. It'll run the machine with as little as 8
> volts in, so I have it set up to power up as soon as I hit "door unlock" on
> my key fob, so it's booting as I start the car.
>
> It's fairly low-tech by today's standards. I wound the transformer on a
> molybdenum permalloy toroidal core because I didn't want to do much
> trial-and-error and those cores are way more forgiving than ferrite pot
> cores. Toroids also have a very contained field and I've been using these
> from Arnold Engineering since the 1970's. I forget what frequency it runs
> at, pretty low, probably 30KHz. It's very efficient, though. It draws
> between 2 amps and 3 amps depending on cpu and disk load. 4 amps at spin-up.
>
> Cheers,
> Bob
>