Description.
The micro ampere meter shown here is basically a DC millivolt meter.The circuit gives full scale deflection for 0.1V input.The current to be measured is passed through a known resistance R and the voltage drop across it is measured.Here the IC 1 uA 741 op-amp is wired as a non inverting amplifier.
Circuit diagram with Parts list.
Notes.
- Assemble the circuit on a good quality PCB or common board.
- Use a +9V/-9V dual power supply for powering the circuit.
- The IC 1 ,uA 741 must be mounted on an IC base.
- The table given below shows the relationship between different values of R and the current that will give full scale deflection.
7 Comments
what are the values of R and what is M1…..?
R3 should be 3.3K, typographical error
Hi Thusihta R values
0 to 1mA for FS R should be 0.1 ohm (100milli ohm)
0 to 10mA for FS R should be 0.01 ohm (10 milli ohm)
0 to 100mA for FS R should be 0.001 ohm (1 milli ohm)
0 to 1 Amp for FS R should be 0.0001 ohm (100 micro ohm)
0 to 10Amp for FS R should be 0.00001 ohm (10 micro ohm)
please give me the values of r
like table
SIR
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