Maker Pro
Maker Pro

Differential Amplifier Doubt

rdevendrakumar1989

Aug 9, 2012
29
Joined
Aug 9, 2012
Messages
29
Hai friends,

Am design a circuit to measure resistance value interms of voltage by using differential amplifier... Am use voltage follower for each input.. But differential amplifier output comes only 70%. am also nullify the offset voltage.. Whats the reason for that.. Give me solution as soon as possible pls
 

Harald Kapp

Moderator
Moderator
Nov 17, 2011
13,700
Joined
Nov 17, 2011
Messages
13,700
Give us a schematic as soon as possible pls.
 

rdevendrakumar1989

Aug 9, 2012
29
Joined
Aug 9, 2012
Messages
29
03045.png



v1 and v2 are the 2 ends or resistor
 

Harald Kapp

Moderator
Moderator
Nov 17, 2011
13,700
Joined
Nov 17, 2011
Messages
13,700
In principle the circuit should work. What are the voltages (supply, V1, V2, Vout)? What type of OpAmp are you using?
Are you sure the difference voltage at Vout is within the operational range of the OpAmps?

Also: The OpAmp has a (admittedly very) small input current.You need to provide a path to ground for this current. See this application note.
 
Last edited:
Top