Minimum Voltages

[linguist]

For an opamp like the TL072, how efficiently would this operate with a dual supply of
+8V & -4V.
I want to use a small single 12V battery & can get the voltages mentioned with it.

I have attached a picture of the dual supply, are their any other reasons this may not work?

I can get more positive voltage but then less negative voltage as a result.

Can I do better than this with just resistors?

Cheers

 

[ericgibbs]

For an opamp like the TL072, how efficiently would this operate with a dual supply of
+8V & -4V.
I want to use a small single 12V battery & can get the voltages mentioned with it.

I have attached a picture of the dual supply, are their any other reasons this may not work?

I can get more positive voltage but then less negative voltage as a result.

Can I do better than this with just resistors?

Cheers

hi,
Use an OPA to provide a low impedance virtual ground, ie: +8v/-4v [or close]

 

[linguist]

Thanks for the reply Eric,

I will check it out.

Cheers

 

[audioguru]

Any opamp works from a single supply voltage if it is biased properly.
Most opamp circuits work perfectly when the reference voltage is half the supply voltage made with 2 or 3 high value resistors and maybe a filter capacitor. Then the input, output and feedback to ground also need capacitors.
Here is an example of the STICKY at the top of this page:

 

[linguist]

Thanks audioguru,

That's what I needed to know.

Cheers