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1  Community / Gigs and Collaborations / Re: Hard amplifier problem - Pleease anwer on: January 05, 2013, 08:10:58 pm
Thaaaanks smiley-grin
2  Community / Gigs and Collaborations / Re: Hard amplifier problem - Pleease anwer on: January 05, 2013, 06:04:00 pm
Did you simulate it?  (my link above, CircuitLab)

Yes, Vout=Vin.  Value of resistor doesn't matter. You can even put 0R.


Yes I did ..
But the graph didn't make sense ..
Maybe I made a mistake .. I dunno ..

But are you sure .. If the op-amp is idea , Vin=Vout .. Even with the positive feedback!
3  Community / Gigs and Collaborations / Re: Hard amplifier problem - Pleease anwer on: January 05, 2013, 05:15:20 pm
I asked this question in another forum ..
Here is one of the replies ...

"""""
The output voltage is:

Vo = Vi / ( 1- 1/A)
where A is the open loop gain of the op amp. so A>>1
you can disregard 1/A then you have.
Vo=Vi
That is a voltage follower. In theory the same as the standard one with negative feedback.

But in real life the output will smack against one rail or the other and stay there. Any difference between the two inputs is amplified and increases the difference rather than reducing it.

""""""


So what he is saying ..
If the Op-amp is ideal .. ( I+ = I = 0 ) and ( V+ = V- ) .. Then , Vin = Vout in this circuit ..

and if it is not ideal ,, the op-amp will be saturated and Vout will be equal to the value of the external power supply ..

What do you think of this???
4  Community / Gigs and Collaborations / Re: Hard amplifier problem - Pleease anwer on: January 02, 2013, 10:13:07 pm
Lefty recognized the trick part right off - this is a problem in electronics, not mechatronics.
You're in the wrong classroom.

Also, your instructor tricked you - it's a really a trivial problem. As everyone here obviously
knows [except OP], you go to the basics for opAmp operation, and then solve for the special
case.

Quote
I really hope I can solve it ..
We all hope you can solve it too.



You all know the answer?!?!?! I feel like an idiot!

http://www.code-lover.it/wp-content/uploads/2012/11/faceplam.png
5  Community / Gigs and Collaborations / Re: Hard amplifier problem - Pleease anwer on: January 02, 2013, 09:22:15 pm
Thaaanks guys
I really hope I can solve it ..
and please, if anyone have any idea please don't hesitate to share your thoughts 
6  Community / Gigs and Collaborations / Re: Hard amplifier problem - Pleease anwer on: January 02, 2013, 08:01:19 pm
But its clearly a homework problem you're passing on to us - if you at least had a go at answering
it first it wouldn't be so galling - people like to help, but cheating isn't helping, its avoiding understanding.

It is a challenge from the teacher ..
He said you can get help from anyone .. But I need you to understand the solution ..
I guess nobody knows how to solve it : (
7  Community / Gigs and Collaborations / Re: Hard transistor problem - Pleease anwer on: January 02, 2013, 07:41:19 pm
its not that hard, and its not a transistor

yupp it's an amplifier .. solve it please!
8  Community / Gigs and Collaborations / Hard amplifier problem - Pleease anwer on: January 02, 2013, 06:45:39 pm
http://i.imgur.com/qmNBA.jpg

  smiley-roll
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