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I am trying to implement a non-inverting operational amplifier circuit; essentially, to double the potential difference of a shunt using the differential amplifying effects of the op-amp, so that I may be able to measure current through it without blowing an ammeter. The schematic I am referencing is:

enter image description here

The following is my attempt at its implementation on the breadboard:

R2=R3

As can be seen on the multimeter, the circuit does not function correctly. Can someone help?

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  • \$\begingroup\$ The ground is broken. The coin cell, shunt and R3 are isolated from the OP-amps negative rail, the load resistor and the 18V power supply. \$\endgroup\$ – Oskar Skog Sep 28 '17 at 5:15
  • \$\begingroup\$ Your shunt essentially isn't in the circuit- you have tied pin 1 directly to Vcc. \$\endgroup\$ – Blair Fonville Sep 28 '17 at 5:51
  • \$\begingroup\$ You are using an ancient 741. Even if your circuit is correct (and think it is wrong) then the 741 wouldn't work properly. In needs a power supply with a higher voltage than the coin cell can provide, and it will not operate correctly if the input signal is within a couple of volts of either ground or the positive supply. \$\endgroup\$ – JRE Sep 28 '17 at 5:56
  • \$\begingroup\$ The pin numbers in the schematic don't match the pins in the wiring diagram. The pinout in the wiring diagram seem to be correct for the 741. But the only error I see is the broken ground. \$\endgroup\$ – Oskar Skog Sep 29 '17 at 16:46
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You are also probably operating the inputs of the OPAMP too close to ground. You will have to check the datasheet on the opamp you are using to see how close you can operate the inputs and outputs to ground and the power supply rail.

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