DC power supply

I want to design a DC power supply in which I can adjust both the current and voltage. I am looking for currents up to 15A and voltages from 0-200V. Would it just be easier to buy a power supply that can support 15A and build an op-amp type circuit with a variable pot to adjust the gain.
This will be put into a nice box with big nobs used to control the V and I.

Im helping my roommate out, he needs it for metal working in which the applied voltage in a medium such as acidic water, changes the color of titanium, etc...

0-200V at 15A is a huge power supply, and (as you are in the USA) couldn't even be done from a 110V outlet.

Are you sure about the requirements, to buy (or even build) one (if you could find one!) would be incredibly expensive - I would certainly expect in the 1000's of dollars.

I don't really know what I'm on about when it comes to anodizing, but I suspect that you don't need 200V and 15A at the same time. 15A may be good to start with, at a few volts, but as the oxide film builds up you require more volts, and need to reduce current to avoid heating effects. At 200V a couple of hundred milliamps may be enough. I suggest you find out exacty what the process needs, and use 2 or more different power supplies, maybe with automatic switching between them.

Hi !

I’ve built something like that a couple of years ago 0 to 250V @ 15 Amps and I used a variac (adjustable transformer) a bridge rectifier and some caps. The variac is obtainable for 127VAC in and 250 VAC out but it is not cheap.

Ante :roll: