DC "dimmer" help

berzai@sbcglobal.net · Joined: 29 Mar 2011 Posts: 74 Location: Indiana

I needed a way to control voltage to a load and wanted to know if anyone could recommend potentiometer. Basically I'm going to anodize a piece of titanium with a 9V chain of batteries, and, if possible, would like to be able to dial to voltage to the work piece ranging from 9v to 50 or 60v. I'm looking a getting the workpiece a dark blue, I know the voltage range of doing that is somewhere between 35 to 45. I could just hookup 3 batteries (27v) see what happens, then add another (36v), and maybe another. But I have a feeling the ideal blue (darkest I can get) is somewhere between the 36v and 45v range.

I'm just looking for an amazon link for a product I could tie in to control voltage. I read diodes could help, but a dimmer would be ideal. Hopefully under 20 bucks? Thanks for the time.

**edit - math

foomench · Posted: Mon Nov 24, 2014 10:17 pm Post subject:

27 volts is pretty close to ideal, but 3 brand new 9v batteries will probably be a little higher than that.

berzai@sbcglobal.net · Joined: 29 Mar 2011 Posts: 74 Location: Indiana

Well that image is extremely helpful... Thanks!

Yeah, 27v does look ideal. I just didn't want any of the purples in there, so actually higher would be better. Thanks for the response. I'm not sure the amp draw on the batteries when this is going on, so really, just not exactly sure what tolerances or range the potentiometer would need.

Kevin59 · Posted: Tue Nov 25, 2014 3:56 am Post subject:

Admittedly I know nothing about the anodization process, but if the fluid bath draws any appreciable amount of current it's unlikely a potentiometer will provide the voltage regulation you're looking for. A resistor voltage divider works well for providing reference voltages to a high impedance device input, but once you start to pull current through the divider the voltage will decrease dramatically (assuming a load referenced to ground).

Any idea how much current you're talking about?