Can someone explain why it's wrong: Inveri

Thread Starter

Hayaalsh

Joined Mar 23, 2013
9
Hi.
I have a question.. Why we cant use voltage divider rule instead of source transformation?
I attached a photo of the problem..
I wish someone explains!

Thanks alot
 

Attachments

t_n_k

Joined Mar 6, 2009
5,448
The 50k loads the voltage divider and is effectively in parallel with the 20k.
It's possible to use voltage divider if you keep the aforementioned in mind.
 

studiot

Joined Nov 9, 2007
5,003
Did you understand why tnk said that?

It is because the input of the op amp is virtual earth.

It is often forgotten in op amp circuits that the inputs are (biased) at earth potential.
 

Thread Starter

Hayaalsh

Joined Mar 23, 2013
9
Did you understand why tnk said that?

It is because the input of the op amp is virtual earth.

It is often forgotten in op amp circuits that the inputs are (biased) at earth potential.
what would happen if the op amp input was not 0V?
 

WBahn

Joined Mar 31, 2012
24,581
Did you understand why tnk said that?

It is because the input of the op amp is virtual earth.

It is often forgotten in op amp circuits that the inputs are (biased) at earth potential.
At "earth" potential?

Huh?

So just how is this accomplished?
 

studiot

Joined Nov 9, 2007
5,003
At "earth" potential?

Huh?

So just how is this accomplished?
OK so it was badly phrased, and I really meant zero. I also should not really have said biased since it is the opamp's gain that causes this.

Perhaps you would like to formalise it.
 
Top