Charge pump for PNP based pedals

[Diego A]

Hi!

   I´ve build a Tone Bender clone that sounds real good but i´m tired of using batteries for power and i´ve heard that there´s a way of change the polarity with a very simple circuit, i´m planning to do more old pnp circuits so i guess it´s time for a long term solution. I have a few max1044 around and i´m looking for a reliable charge pump design and wiring to try out.

    Any advice from other wise stompboxers will be gratefully recieved.

    Cheers and thanks in advance.

[diffeq]

Hi. MAX1044 is a good chip, but its maximum supply voltage is 10V and pedals run at 9V. If you'd want a bit more headroom in case of PSU "hiccup", TC7660S is anologous chip that runs on up to 12V of supply voltage.

[Diego A]

Thanks!, that´s what i´ve heard about the max1044 but i guess that if i run the thing through a stable 9v source i would´t have any trouble. Do you have a circuit suggestion?

[BetterOffShred]

Tagboard has a 7660 voltage inverter layout found easily with a Google search.   

Get your 7660s from a reputable source like Mouser, there's a bunch out there that whistle. 

[Diego A]

Thanks! i saw the circuit and seems pretty simple. what are those white and red squares in the layout?

[BetterOffShred]

Cuts.  You use a drill bit and an Xacto knife to remove strip.  Read the guide there on the main page dropdown.  Stripboard is easy once you know what's going on.   

[Diego A]

Thanks a lot again! you know i still have those max1044 and i wanna use them even if they die soon after, can i replace the 7660s´s with those in this layout?

[BetterOffShred]

I think you should be able to. Another way to protect your 1044 is to make a little daughter board with a 7809 regulator on it.. so you'll never get more than 9 volts going to the 1044.  Works pretty good.  The data sheet will shoe you which pins are which.   Just hook the supply pin up to your power supply positive lug, and then a row for ground and then the "out" pin supplies regulated 9v(ish) to your inverter board 1044. 

[Diego A]

Thanks again dude! you rock, i´ll put my hands to work as soon as i get home.

[R.G.]

Let us know when you've used them all up and want to change over.

[Diego A]

I think you should be able to. Another way to protect your 1044 is to make a little daughter board with a 7809 regulator on it.. so you'll never get more than 9 volts going to the 1044.  Works pretty good.  The data sheet will shoe you which pins are which.   Just hook the supply pin up to your power supply positive lug, and then a row for ground and then the "out" pin supplies regulated 9v(ish) to your inverter board 1044.

It worked!! great! now i can gig with my germanium pedals with no extra supply.

   Thanks again

[BetterOffShred]

Glad to hear it man.  I'm sure others will be glad to hear the germanium fuzz