David,
I used a couple elements from a 120 VAC toaster as a dump load for a while. A typical two slice toaster here has three elements, two on the outside that are wrapped on one side of a card, and one in the middle that is wrapped on both sides. The two on the outsides are connected in series, and they are connected in parallel with the card in the middle.
Splitting the outside cards and running them as a dump load on a 48V system (at about 56VDC) was about equivelant in terms of power, I tapped the middle element and with the outside cards ended up with four sections that would draw about 250 Watts each. You could split up the elements to work on 12V and from the toasts perspective it would be equivelant.
The control to pop it would be a bit more difficult. It appeared to work by heating up slowly when about 8.3 amps went through it, causing it to slowly distort and ultimately cause the toast to pop. I doubt it would work out too well with 83 amps DC unless you liked your toast rare, and even if you got arround that, the contacts would almost certainly be destroyed in short order switching that much current.
You could cut the current load in half if you only wanted to toast one slice at a time. Then you could use a 40 Amp DC breaker (I have one, and I think it costs more than a cheap toaster), or a bunch of FET's to switch the current, and you could build a circuit, maybe 555 Chip based, with a potentiometer to adjust the timer for how brown you wanted your toast.
After all of that, you would still have to handle 40 amps to the toaster, which would require about size U.S. Guage 8 Wire.
While it could be done, I am not sure it that is where I would spend my time and energy on my system. Rich
