Dual polarity power supply for circuits

[dayanj]

I am looking for a dual polarity (+/-6V) power supply for use with simple circuits.

I found these DC to DC converters which have +/- 12V outputs. Do you think I can use that +12 and -12V outputs connected to two potentiometers to regulate it to any voltage below 12?

I have attached a sketch of what I plan to do? are there any potential barriers for using it like this?
thanks

DJ

 

[davenn]

hi there DJ

a voltage divider like that would be ok for low currents any signif current and the resistors are gonna get real hot.
you would be better off using +5V and a -5V voltage regulators off each of the + and -
rails. (3 pin 7805 and 7905 Reg chips for example)
You didnt state what your power supply's current capabilities need to be ? ie. what sort of current is the load going to draw from each supply rail ?

Dave

 

[shrtrnd]

Yeah, a little more info about what you're going to use it for, would help.
If you need the 6VDC, you could bump up to the 7808/7908 (8Volt regulators), with a fixed resistor to drop the 8V to 6V. If you expect high currents, get the TO-3 power transistor package. And like davenn said, you gotta be aware of your current draw, for the right size dropping resistor.
A high current dc/dc converter is going to run you some cash, and the voltage regulator idea from davenn would be a lot cheaper.

 

[dayanj]

Thanks a lot for your replies!!
My applications are phase locked loop with LM 565/ NE 565 in FM demodulation mode,
and some simple op amp circuits like voltage multipliers etc.

I found that voltage regulators, which seems a good option for me to use combining with +12 and -12 outputs of DC-DC converter. Thanks a lot again!!

 

[shrtrnd]

Low current circuit, ....
Your circuit should be pretty simple and inexpensive.

 

[dayanj]

Thanks a lot

DJ

 

[dayanj]

btw, are there any dual polarity power supplies commercially available for this purpose?
ideal one should have three outputs wit +,- and ground. and output can vary between +/- 5V to +/- 12V ?

 

[Militoy]

If you don't need more than around 100mA on each output - you could use a dual adjustable LDO linear regulator like the LT3032. They're good for +/- 1.22V up to +/- 20V or so. They're not technically a "power supply" - as you'll have to feed in unregulated DC - like from a dual-complimentary rectifier.

 

[dayanj]

Thank you! I think that is the best option for me for my range of applications!!