I need a design for a constant current source that can deliver a hefty current at around 12 volts with at least 1-2 amps, preferably up to 5. Every current source I've seen uses BJTs or resistors that are submitted to the same current as the load, but I don't want to dish out the money for a 100w resistor or BJT.
I'd like to avoid an LM317, though I'll do it if it's the best option. Is there a good constant current source design that can deliver 12v @ 2-5A using, say, op-amps or mosfets?
The output doesn't need to be perfectly stable, I just want to prevent any components (namely electrolytic caps) from blowing up.
Thanks for any help