So i got lucky and found a rack of 10 TL071IP linear opamps laying around. I need to use one eventually to amplify the voltage off of a piezoresistive sensor. I attached the setup.
The sensor varies from about 20k to something my multimeter cant measure (>40M).
So as the topic title suggest the problem is in the opamp output. putting the oscilliscope on + pin on the opamp gives me a nice .2v to 4.16v reading, which is expected. However the output of the opamp does this weird clipping thing... whenever the sensor is completely depressed (in the >40Mohm state) the opamp output is 4.56v, but then when i touch the sensor the slightest bit (reducing the resistance to the 1-2Mohm range) the opamp outputs as expected.
So my question to you is:
is this a busted opamp or am i simply not delivering enough current to to the + port for the amp to make a useful reading?
Please help, ive been stumped on this for a while
~
The sensor varies from about 20k to something my multimeter cant measure (>40M).
So as the topic title suggest the problem is in the opamp output. putting the oscilliscope on + pin on the opamp gives me a nice .2v to 4.16v reading, which is expected. However the output of the opamp does this weird clipping thing... whenever the sensor is completely depressed (in the >40Mohm state) the opamp output is 4.56v, but then when i touch the sensor the slightest bit (reducing the resistance to the 1-2Mohm range) the opamp outputs as expected.
So my question to you is:
is this a busted opamp or am i simply not delivering enough current to to the + port for the amp to make a useful reading?
Please help, ive been stumped on this for a while
~
Attachments
-
35.8 KB Views: 31
Last edited: