18V What should I do?

[milkwasabadchoice]

Ok Im ready to buy the parts for GGG ultra-clean power supply. I just relized I need 9v and 18v for my Line 6 DL4. If I use a 25v transformer is there another type of reg for 18v i can hook up from the same transformer? Thanks for the help!

Jason

[nelson]

7818 1A 18v regulator.

[grapefruit]

I was thinking, if you need regulated 9V and 18V supplies,to save from stocking different parts you could use two 7809 regs and put the ground pin of the reg you want for 18 volts to the output of the 9V reg. This should be ok if you're running them both off, say 24V. But it may be a problem if you have a seperate lower rail for the 9V reg to save on power dissipation. If that output was not at 9V before the 18V reg got volts going to it there may be a problem.

I'm not too sure. Anyone know?

Personally I wouldn't run a 9V reg from 24Vac. Too much power dissipation in the reg. P=VI

Stew.

[spudulike]

9V zener on the reg common leg to ground. Moves the regulator reference point.