On Sun, Feb 12, 2012 at 9:04 AM, Mark Hanchey wrot= e: > On 2/11/2012 4:15 PM, Nathan House wrote: >> I'm burning through batteries like nobody's business and think it's >> high time I purchased a power supply. I know I can make my own board >> with voltage regulators for common voltages like 3.3, 5, 12, etc, but >> I think I'd rather have something that's adjustable and can source a >> lot of current in case I ever need it. >> >> Thanks, >> >> Nate >> > > I realize you are looking for something pre-built but I have found a > LM317, pot, =A0transformer, bridge and some caps was the way to go and if > you want high current you can add a pass transistor and do it all for > way cheaper than anything you will find online. =A0Completely adjustable = , > mine goes from 1.6 to 18, current can be whatever you need. You can also > do negative voltages easily which cost a lot more if you buy a pre-built > supply. > > What I did is get a center tapped transformer and it is connected to > several regulators =A0a 3.3, 5, 12V and it also connects to a 317T and > transistor , so on the supply I have 3.3,5,12v,-5v,-12v, 1.6-18V > variable and I can use them all at the same time if I want. I connected > them to a barrier strip to make it easy. > I second the "Not what the OP asked for but still...". With a transformer I pulled out some old appliance, an LM317, a few diodes and resistors, a potentiometer and a switch I made my own power supply in an evening. I just use my voltmeter to set the voltage I need for any given application. Save for the LM317 and a bit of perfboard, everything else could easily be pulled out of some other broken piece of household electronics. So my total cost was around $1.50. Oh, and for style points I housed it all in a plastic diaper wipes box. For the leads I used a shielded stereo RCA cord I had laying around and put a couple alligator clips on the end (again...style points). Again, not what you asked for. But more fun. And cheaper. I'm sure someone else will answer your actual question =3D) -Eric --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .