When using a charge pump for a positive ground circuit does the circuit use...

[jimmybjj]

same ground as the charge pump? Specifically i'm speaking of the fuzz face circuit using a charge pump. Does the fuzz face circuit using the same ground as the charge pump or are there two separate grounds? Thanks for any help.

[tubelectron]

Hi - it will seem a stupid question at the first sight, but as English is not my native language, it is not so stupid in fine...

What do you call by charge pump here ?

In French = pompe de charge, pompe de mise en pression, pompe de remplissage, pompe de relevage, circulateur... Nothing electronic, all hydraulic !

So,

A+!

[slacker]

He means something like this Bruno http://www.geofex.com/circuits/+9_to_-9.htm that lets you create a negative voltage from a battery or positive DC supply.

To answer the question there is only one ground, you connect the ground connection of the Fuzz face to where ever ground is on the charge pump circuit.

[tubelectron]

Ah, yes... - OK, slacker - I see. It's a kind of DC to DC voltage doubler / converter - Thanks !

[Govmnt_Lacky]

Need to do a bit of grave diggin' here.... 

OK..... so I want to use a charge pump to power a PNP Fuzz Face so I can connect it to the same PS as my other pedals. Let me explain where my disconnect in logic is.

1) I wire up all of my off-board stuff the same as an NPN circuit (i.e. In/Out jack sleeves going to DC jack GND, 9V battery black wire to Input jack Ring)

2) I connect the grounds from #1 to Pin 3 of the charge pump.

3) I connect the +9V (V+) from my battery/DC jack to Pin 8 of the charge pump.

If I install the appropriate components (caps, etc.) in the charge pump circuit.... I should have -9V coming out of Pin 5 of the charge pump.

Using this diagram as a reference:

http://www.tonepad.com/getFile.asp?id=82

Where do I connect my -9V (V-) output from the charge pump Pin 5?

-and-

To what/where do I connect my V+?

Sorry if this has been asked a zillion times but, I just cant wrap my brain around this one 

[slacker]

You build the positive ground version of the fuzzface. Then "Red wire" on the tonepad board goes to  ground from your point 1. "Black wire" goes to -9 from the charge pump (pin 5). +9 doesn't go any where on the fuzzface circuit.

[Gurner]

fwiw, having previously used specific dedicated ivoltage nverter ICs, I decided a few days ago to make a voltage inverter with a PIC, two caps & two diodes...the PIC in this instance is just acting as a square wave oscillator therefore if you aren't into PIC/MCUs you could substitute it with a 555  timer like this

http://www.aaroncake.net/circuits/vinvertr.asp

....the resulting negative voltage works just fine for an opamp bipolar supply....and IMHO way trumps a virtual earth arrangement.