CM plexitone power mod?

[petesz]

Hey all,
So my friend has a Carl Martin Plexitone that he wants to be able to run on a normal 9v adaptor. I agreed to do the mod for him thinking it would be a straightforward case of using the road rage as a charge pump to power the 12v, but I was just reading the thread over at freestompboxes and it seems it's a bit more complex than I originally thought..
Is there a way to use the road rage to get both +ve and -ve 12v power at once?
Or has anyone done or heard anything about this mod? I know This dude does it: http://www.hugeracksinc.com/forum/viewtopic.php?f=1&t=75535
Would anyone be willing to help me out on this?

[stecykmi]

easiest solution is to buy a 12v power supply, then use the roadrage (with a suitable chip to handle that voltage).

otherwise, i don't really know much about them, but there should be a voltage regulator that will step up 9v to 12v. then it's easy enough to use a roadrage, as above.

[petesz]

Hmm so maybe I could use a roadrage to step up from 9v to 12v, then use another road rage to get the +/-12v?

[jkokura]

I think instead of using two Road Rage boards, you should learn a little bit about how charge pumps and either create a layout for a charge pump that will take 9V in and give you +/-12V out...

Jacob

[petesz]

Ok.. so ive done some reading.. but still not sure how I can do this. I think my problem is i dont really understand bipolar power supplies..
Might be easier to use a 12v power supply and then just use the road road to get the bipolar supply..

[cjkbug]

Ok.. so ive done some reading.. but still not sure how I can do this. I think my problem is i dont really understand bipolar power supplies..
Might be easier to use a 12v power supply and then just use the road road to get the bipolar supply..

doesn't that defeat the purpose of what you are trying to do?. jkokura was right. stdy up somemore and experiment on a bread board till ya crack that nut. then wright back and tell everybody what ya did. you'll be a hero.

[stecykmi]

Okay, there is likely a better way to do it, that uses fewer components, but this should work:

Use a 1044 to step up the voltage to ~18v. Use a voltage regulator (7812 is the p/n) to bring the voltage to a even 12v. Then use a second 1044 to make a split power supply at +/-12v.

If you're using a roomy enclosure, it should be okay. Rather inefficient since it's using 3 voltage converters, but nothing's perfect I guess.