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Help with controller circuit for galvanic etching machine? How can I eliminate the halogen lamp from the circuit?

I want to put together an electroetching rig (as detailed here), and I already have a battery charger, but I need to make the controller (diagram attached).
My question is: Is there a better solution for the circuit than having an 12 volt halogen lamp wired in? That just seems really clunky to me, and my gut tells me there's a better solution that is not "go buy a laboratory power supply". I have nothing against old-school, but this looks positively prehistoric. Anybody?

Picture of Help with controller circuit for galvanic etching machine? How can I eliminate the halogen lamp from the circuit?
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Well, you COULD build a big linear current regulator, but you're not going to change the basic physics of the thing, and you'll still have to dump a lot of heat somewhere. The ultimate answer would be a switch mode PSU, but that's a lot more effort than buying one.
RavingMadStudios (author)  steveastrouk7 years ago
Are you sure there's nothing more elegant out there, possibly involving an 18V cordless drill motor, an Arduino and a 55-gallon Altoids tin full of saltwater?
Yeah, OK. I was afraid of that.
Try Ebay first. Its the controllability that stuffs the chances of an easy solution.

Steve
RavingMadStudios (author)  steveastrouk7 years ago
I'll go have another look, but I'll probably just wind up going with the halogen bulb. I'll just be sure to wear my steampunk goggles while I'm etching. Thanks for your help.
You should be able to find a computer power supply for $0 to $20 on Craig's List.
True, but I'd still have to build a controller for it. Besides, I have a perfectly good battery charger already. Might as well use it, unless I can get a lab supply for less than the controller components will cost me.
because if you fry a free computer power supply experimenting with the altoids tin full of saltwater, you don't have to buy a new battery charger!

Put the light in a Easy-Bake oven and make cookies while you etch.
RavingMadStudios (author)  Scubabubba7 years ago
Good point, I do rather like my battery charger. And everybody likes cookies.