12-0-12 power spliting for Opamp project (?)

[Willen]

I need to use few Opamp for audio compressor and equilizer. I could use 12-0-12 transformer but if I used the 220V mains for transformer, my basic FM transmitter start to roar (the compressor and equilizer for the FM Tx ). So I need to use battery. Using two batteries is not practical for me (not available always). So I have to make a power spliter from 12V to 12-0-12. I couldn't find any dedicated common IC too. It seems complicated. I need to supply two or three dual and quad opamps.

I used my silly mind and thought to use 4047 inverter IC. It pulses 12-0-12 to transformer's input at basic inverter. Can't we take this 12-0-12 for OpAmp?

Or if you have a nice simple alternative it would be EXTREMELY nice for me!

Regards

 

[CapeCAD]

You could use a Bipolar/Dual Output Isolated converter like the Murata-Ps MEV1D1212SC which takes a 12V input and supplies +/-12V output

 

[crutschow]

Below is a simulation of a 555 switched-cap supply that generates a negative voltage approximately equal to the positive voltage.. Due to the voltage drops of the Schottky diodes the negative voltage is about a 0.6V less than the positive supply but that's typically not a problem in op amp circuits. The quiescent operating current is about 9mA in addition to the load current.

The maximum load current is about 12mA. For more current you can reduce the value of R4 and R5 at the expense of more quiescent current.

 

[Willen]

Wow CapeCAD,

It looks so easy and handy but unfortunately I am in a place where I just can find 555 as a chip

Hi Crutschow,

It looks nice but just 12mA or little more output is enough to power asingle dual OpAmp, isn't it? I need to supply almost two dual and one quad Opamp.

It seems so critical matter so people are not suggesting as usual here.

 

[crutschow]

So what op amps are you using and what load are they driving?
If necessary you can bump up the current by reducing the value of R4 and R5 to provide more drive to the transistor switches.