Advice for both 12 and 9v on one system

[mattb]

I have an AD-20 that runs on 9v and then I went all cheap and got an ART Phantom II instead of a PS-2. I saw that the ART ran on two 9v batteries, but I didn't know if it was in series or parallel. Turns out it's series since it wants 12v in from external power. I also want to build an external meter like Nick posted about and those seem to want 9v as well.

I'm toying with the idea of going with either RC or a Makita drill battery (both 9.6 v), but that won't cut it for the Phantom II.

Anyone got a good idea to provide both voltages? I may just bite the bullet and spring for a PS-2 to simplify this.

I just thought I'd bring it up here in case there's a good idea I need to hear.

[Chuck]

I built a 12v - 9v voltage regulator. It was pretty easy to make and allows both voltages off the same SLA.

[mattb]

Cool!
Do you have any plans or instructions for it?

[Chuck]

This is the chip I used LM317:

http://www.national.com/ds/LM/LM117.pdf

You can adjust the voltage out by changing resistors.

[Chuck]

This is the chip I used LM317:

http://www.national.com/ds/LM/LM117.pdf

You can adjust the voltage out by changing resistors.

I built mine into a Rat Shack project box. I had the voltage meter from another half finished project and added that as a battery tester. I'd be happy to help you put one together. I made it so it's a totally separate unit from the battery. I originally had it attched to the top of a 12v SLA, but when I had to buy a second SLA, I made it a stand alone unit.

[mattb]

I have a little multimeter I carry in the kit. I'd probably rely on that for testing and would probably make the SLA system pretty basic. I'll check that link out and let you know if I have questions. Not sure when I'll get to this particular project as I have a couple of others I should probably do first. Thanks!

[Chuck]

It is a very simple circuit, The regulator IC, two resistors and a couple of capacitors. I added panel mount 4 pin XLR's for splitting out power to different devices. If you don't already have a fuse on your SLA, you can also build one into the box.

[BCostigan]

You could always just run them both off 12 volts.......the ad-20 accepts 5.5 -> 25v dc.

[mattb]

You could always just run them both off 12 volts.......the ad-20 accepts 5.5 -> 25v dc.

Really? I didn't know that. That would simplify things quite a bit.

What are you guys using for SLAs these days? Any particularly good/bad items or vendors to be aware of? I don't think I'll have a lot of draw, so for me the smaller the better (I like to travel light)