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OpAmp Dual Power Supply

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vinil1410

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I am using 741 opamp in my circuit to be printed on pcb. How can i give vcc= +12v and vee= -12v power supply to opamp??
 
I tried to use split power circuit using diodes and capacitors. But for that i need input of 24v dc. 24dc adapters are not available. So what is the other method of dual power supply?
 
Last edited:
To power just opamps (light load), I have done this:

Note that a 12V transformer gives ±17V, which is enough if you plan to use an LM7812/LM7912 to regulate the opamp supplies. A 9Vac out Wall-Wart would make ~ ±12V without regulation.

Unless you are using the +12V or -12V as reference Voltages in your circuit, opamp supplies do not have to be regulated. Most modern opamps have Power Supply (ripple) Rejection Ratios of > 90db, so regulating their +- supplies is not needed. Look up the specs for the 741.

btw-the 741 is an extremely crummy old opamp. There are hundreds of modern, cheaper ones with better specs.
 

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Last edited:
To power just opamps (light load), I have done this:

Note that a 12V transformer gives ±17V, which is enough if you plan to use an LM7812/LM7912 to regulate the opamp supplies. A 9Vac out Wall-Wart would make ~ ±12V without regulation.
That's an easy way to get plus and minus voltages from a single AC voltage. Somehow I had not really considered using two half-wave rectifiers off one winding for that purpose, but it's a good idea for light loads when ripple is not a big concern. And you could certainly add a couple linear regulators if you needed low ripple and better regulation.
 
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