Wheatstone bridge amplifier circuit

Thread Starter

jstrike21

Joined Sep 24, 2009
104

I found Vout of just the wheatstone bridge part is:
Vin((10.01/20.01)-(10/20))
Using 5 as Vin i got Vout=0.00025V

Does the 0.00025 Volts go to the + terminal of both of the op amps?
I'm not sure how to solve from here.

I know the transfer function of the amplifier circuit:

is

would I use the 0.00025 as Vin2 and 0 as Vin1?
 

t_n_k

Joined Mar 6, 2009
5,455
I would imagine in a real circuit implementation there would be a power supply common reference at some point - say at the lower point of the bridge. Otherwise one might have issues with lack of conducting paths for input bias currents - should they be non-zero.
 

t06afre

Joined May 11, 2009
5,934
Google -> instrumentation amplifier This will give you some tips. A instrumentation amplifier will amplify the difference between the two inputs.
 

jlcstrat

Joined Jun 19, 2009
58
It's going to amplify the difference, but as far as the formula goes wouldn't you use 2.5 and 2.5012 for the V in 1 and 2? I thought that was the original question.
 
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