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8th August 2019, 10:48 #1
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Isolate R37 from Equation
Hi,
I need to Isolate R37 from the attached Equation.
The Resistors and Vo, Vf,VCC need to be in the equation.
Any Solution?
Thanks,
Doron

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8th August 2019, 18:19 #2
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Re: Isolate R37 from Equation
R37 is a very important part of the circuit since it and R42 set the input voltage of the opamp, then since the opamp has a gain of 1 the output voltage of the opamp is also set to be the same as the input voltage.

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8th August 2019, 18:26 #3
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 Jan 2019
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Re: Isolate R37 from Equation
try this:
apply voltage divider at the + input of the op amp V+ = ...
assuming a perfect op amp, V and output = V+
combine R25 and R28 to one equivalent resistor
assuming Vo is open, apply voltage divider (Vf, R21, V+ and equivalent R25R28)
when you have Vo = ..., replace V+ with what you got above
follow the rules of algebra
expand everything so there are no parenthesis and no fractions
put all terms with R37 on one side of =, everything else on the other side
factor out R37 and divide
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