Help Building a Power Supply

[zbblanton]

Does anyone have experience in building small power supplies? I need help building a power supply that can accept voltages between around 7v to 9v. It needs to be able to step up that voltage to 12v with at least 1.2amps, or two split rails with about .6 amp. Also needs to be able to step down to 5v with 3amps or on 3 rails, each with 1amp.

Anyone with any help at all would be greatly appreciated.

[snowcolt17]

couldnt you mod a old pc psu?

[FOOKz™]

Your asking for a DC to DC converter. From what i read you want to use 7v-9v and convert it to 5v and 12v ?

This isn't necessarily a difficult build; but the amperage you want to work with is pushing the price tag up for this power supply.

[lilunwl]

http://www.instructables.com/id/How-to-Build-a-Bench-Top-Power-Supply/

http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

Google can be your best friend.

[zbblanton]

Sorry I should have been more clear on the the size of this project. I'm building this PSU for my robotic arm. The Servos are going to run direct line from the battery. But then I have serveral  different items I have to power as well. For instance I have a Wired IP camera and a wireless router that take 12vdc.

I actually already designed the 5v step-down convertor:


I also think I've found a few step-up boards I can use that would be cheaper then building them. Thing is, I really don't want to have to wait a whole month to get my step-up convertor from Hong Kong if it would be easier to just build one.


I was just trying to found your guys suggestions to see if you guys have better solutions. Thanks for the help so far, its much appreciated.


Update: I found this voltage regulator:
http://www.national.com/mpf/LM/LM350.html#Overview

This is a pretty easy circuit to build and I could just up the input battery to 12v and use 2 or 3 of these to get my desired amps.


Update: I've build a test adjustable voltage regulator. It works great. It can adjust between about 1.2v to 11v when its on a 12v supply.