LM741: how this circuit works

HARI T O1

Expert 1675 points

Part Number: LM741

Dear Team,

I dont quite understand how this circuit works. Can anyone help me analyze this circuit?

I only understand the second stage (the inverting output) but i have no clue about the left part.

Regards

HARI

over 1 year ago

0 Caro Walter over 1 year ago

TI__Mastermind 22362 points

Hey Hari,

It's a little unfamiliar, hopefully I can convince you to use a more up-to-date op amp.
It looks like a inverting summer circuit but instead of sources, they are produced by buffers:

Inverting summer circuit

Could you share the source of the material? I reverse image searched on google and found a stack exchange that was probably posted by you: https://electronics.stackexchange.com/questions/708395/buffered-power-supply-with-op-amps

All the best,

Carolina

0 HARI T O1 over 1 year ago in reply to Caro Walter

Expert 1675 points

Hi Carolina ,

Thank you very much.

Yes it is from stack exchange.

Here Vx is always at ground potential .Correct me if I am wrong.

Regards

HARI

0 Caro Walter over 1 year ago in reply to HARI T O1

TI__Mastermind 22362 points

Hey Hari,

Do you have the original source of the picture?
Looks like maybe a textbook?

All the best,
Caro

0 Ron Michallick over 1 year ago

TI__Guru**** 167646 points

Hari,

The math for Vx is RL/R * (Va1 + Va2). When RL terminates to ground. A virtual ground in this case.

The left side is a self referencing summer that adds currents to Vx node, so Vx would go infinite gain without a load RL. I can't think of a practical purpose for this circuit.

+1 Caro Walter over 1 year ago in reply to Ron Michallick

TI__Mastermind 22362 points

Hey Hari,

Could you tell us more of what the application is?
We would like provide a purposeful circuit with a more modern device, if possible.

All the best,
Caro

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LM741: how this circuit works