12v to 9v Layout

[Kinski]

Anyone have a 12v to 9v layout?

I'm planning on building the Tiny Giant Amp (modded to use a 12v 4A+ power supply). For a preamp, I'm gonna use an overdrive circuit of some kind. But that will need 9v. So I will need to bring the 12v down down to 9v.

If anyone has a layout, I'd greatly appreciate it!

[Kinski]

Actually, how about this. I built a JHS Superbolt with a chargepump at 18v when fed 9v. This circuit has needed a home, so I would like to use this for the preamp.

Can I alter the charge pump so it puts out 18v from the 12v power supply instead of from 9v supply?

I'm using johnk's superbolt layout located in the layout section.

[Kinski]

If 12v to 18v is not possible, then a 12v to 9v would still be of great use to me then.

[IvIark]

Use a 78L09 9V regulator.  12V in, 9V out.  You could even then feed the 9V into a charge pump to give you an 18V output if you prefer.

[Kinski]

So I could just get a single 78L09, run the 12v IN pin, GROUND pin to ground, and OUT pin will be 9v?

[IvIark]

Yes

[Kinski]

Awesome. One last question, I promise!

I'm using a 12v 4A supply.
Do I need to use the heftier L7809 (1.5A) or can I just use the smaller 78L05 (100ma).

[IvIark]

The current isn't determined by the power supply, just by what the circuit draws. So although the power supply could burn out the regulator. It won't unless the circuit needs more current than the regulator can supply. So unless it's a real monster circuit I wouldn't worry about it

[Kinski]

Thanks!

[bassbuddy]

The 78L09 has internal temperature protection and current limiting. So no worries at all.
However it is recommended to add two 0.1 µF capacitors between
1. Input terminal and ground
2. Output terminal and ground