power an op amp with 12V from a 24V power supply

K

kalekye

New Member

• Aug 16, 2012

• #1

am trying to make a circuit that can power an op amp with 12V from a 24V supply using the voltage divider theorem, thank you

 

3v0

Coop Build Coordinator

Forum Supporter

• Aug 16, 2012

• #2

A voltage divider only works well when you have a fixed load on the center.

The op amp will not always draw the same current. You need to be using a voltage regulator. Going from 24 to 12V you may need a heat sink on the regulator.

 

K

kalekye

New Member

• Aug 16, 2012

• #3

I was hoping I could obtain both +&- 12V will that mean I need to use two voltage regulators

 

audioguru

Well-Known Member

Most Helpful Member

• Aug 16, 2012

• #4

The input of an ordinary 7812 voltage regulator must be at least +13.5V for it to regulate the output at +12V.
The 7912 negative regulator needs a minimum input of -13.5V. Then your raw power supply must be at least 27V, not only 24V.
Then you need a circuit to divide the input voltage which also needs additional voltage.

 

ronv

Well-Known Member

Most Helpful Member

• Aug 16, 2012

• #5

Depending on the circuit sometimes a virtual ground can be used for the op amps. Is that what you were looking for?