# Dual output power supply

Discussion in 'The Projects Forum' started by IATCUYB, May 29, 2009.

1. ### IATCUYB Thread Starter New Member

Dec 23, 2008
6
0
I need to power two devices.

A CCD which runs on 12VDC and a bunch of LED lights that run on 24VDC. I would like to use two car batteries if possible in series for the LEDS lights, but how would I get the 12V to the CCD? Both devices together draw less than 1 AMP.

Would it be possible to regulate the 12V?

Thanks!

2. ### rvh002@gmail.com Active Member

May 15, 2009
118
2
The question seems to be strange. One battery gives you 12volts and that is where you take the supply from. Two batteries in series gives you 24 volts and that is how you take the supply. If the variance in output voltage from the batteries is a problem, you could add a simple voltage regulator to keep it constant. 12 and 24 are simple off the shelf regulators for up to 3amp. You have to keep the batteries charged, or else add voltage convertors. (The regulators normally need a 2-3 volt higher voltage than the output) Look or ask Bill Marsden about his voltage convertors if really necessary. Normally the equipment will work directly off the batteries. (If kept charged)

3. ### Wendy Moderator

Mar 24, 2008
20,766
2,536
A simple linear regulator would work off the 24 V, if the battery voltage off the single car battery wasn't good enough. That or a buck boost regulator circuit, the effeciancy is much greater. You didn't mention how clean the 12V needs to be.

Personally I think the 12V off the battery would be enough in terms of regulation.

Have you given any thought on how you would recharge this setup?

4. ### mik3 Senior Member

Feb 4, 2008
4,846
63
Since the current requirement is less than 1 Amp then a linear voltage regulator like the 7812 will be fine.

Connect it the the 24V and attach a heatsink on it to dissipate heat faster.

5. ### IATCUYB Thread Starter New Member

Dec 23, 2008
6
0
Thanks, between you guys and another that has been helping out I went with a 7812.

24 volts go to a mass of LEDs and the 12v goes to a CCD. The LEDs can handle +/- 4 volts but the CCD can't.

I use car batteries because they are easier to maintain out in the field and rarely if ever do they "just stop working". If something happens I can go to any Wal-Mart or Auto Parts store and get another battery for less than \$40.

Again, thanks for the replies