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M.Joshi M.Joshi is offline
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Posts: 134
Arrow

I do not remember the values of all the components as I only saw the circuit for a brief moment in an interview but, as far as I can remember, the positive input was connected to a potential divider consisting of two equal value resistors to +Supply and -Supply.

The invering input was being fed from a mic pre-amp circuit which I believe was capacitively coupled and there was another resistor in series with the input.

CJT - Could you give me some pointers as to how I would go about an Op-Amp analysis as it has been some time since I have done one.

Thanks.


Quote:
Originally Posted by CJT
M.Joshi wrote:
I have attempted an ASCII drawing which can be downloaded from the
following location:

http://three.fsphost.com/Joshi

Filename: Op-Amp Schematic.txt

I hope it makes things a bit clearer - It is the purpose of the
capacitor (C) in the diagram that I am not too sure of?


Isn't there a resistor on the input, too?

Assuming there is, you ought to be able to do a typical op-amp
analysis -- the sum of currents into the virtual ground at the
inverting input will be zero.



Sam Goldwasser Wrote:

M.Joshi writes:

Just to clarify a few points:

I have come across a capacitor on the input which is to block DC; and
also in the feedback loop which gives an Integrator function I
believe
however, in this circuit, there was a resistor in the feedback loop
and
another resistor and capacitor in series to ground from the inverting
input?

Thinking about it now, could it form some sort of filter (Low pass)?

How about drawing the circuit?

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