Negative voltage from charge pump

[scotsman]

I'm looking to add a charge pump to my Maxon Analog Delay - which uses -12v so I can use my normal 9v power supply and ditch my failing wall wart. 
The question I have is - is it possible to get negative voltage from a charge pump?  Is it as simple as flipping the Electrolytics and diodes around? 

Any help is greatly appreciated!

[Sir H C]

Yes it can be done.  If you look at www.maxim-ic.com or other makers of these charge-pumps you can see how to configure them to get negative voltages and which ones can do it.

[scotsman]

I've got some max1044's - and I've looked over the data sheets and it's like braile to me.  I don't get it.

Could I run negative power through the circuit as is?  Will it still "boost" properly?

I'll be using this layout.

[johngreene]

I've got some max1044's - and I've looked over the data sheets and it's like braile to me.  I don't get it.

Could I run negative power through the circuit as is?  Will it still "boost" properly?

I'll be using this layout.

This is the voltage doubler configuration for the max1044 and will only work with positive voltages. The 1044 will create a voltage equal to and opposite in polarity of the input voltage only. The data sheet says you can cascade 2 or more devices to get negative voltages greater than -Vsupply but the output impedance rises dramatically. 5x for 2 devices in cascade.

--john

[Sir H C]

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1017

Shows at the bottom the inverting configuration of the 1044, with use of 5 pins (named).  So using that and knowing which pins are which you should be able to get one cranking pretty quick.

[johngreene]

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1017

Shows at the bottom the inverting configuration of the 1044, with use of 5 pins (named).  So using that and knowing which pins are which you should be able to get one cranking pretty quick.

Except he is looking for -12V. The inverting configuration you are referring to will only give him -9V.

--john

[mattumbi]

Make sure to check the current rating for the delay unit & the charge pump...

[scotsman]

I got it fired up - it puts out around 20 volts and climbs using 1n4001's! when I get it grounded the 1044 starts getting warm.. So something is wrong!   The jumper from pin 2 runs to the negative on the 10µf cap?  A grounding issue?