Isolate R37 from Equation

1. 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  Reply With Quote

•

2. 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.  Reply With Quote

•

3. 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 R25-R28)

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  Reply With Quote

--[[ ]]--