Hi I would like to build a very simple mosfet voltmeter. Mosfet, so that it does not load the measuring circuit. It will use an analogue meter.
Can I use the 2n7000 to build this https://www.youtube.com/watch?v=YkZuBu-EUhc ???
What if I want to also measure negative voltage as well? Shall I just connect the ground to the gate and the negative voltage to the source, will that be ok?
Look at FET Id=f(Vgs) curve and see if it's of any use for your purposes. The idea of using a calibration series resistor raises doubts about the author's analog design skills. Might be copy-and-past error while modifying an original common drain circuit.
Look at FET Id=f(Vgs) curve and see if it's of any use for your purposes. The idea of using a calibration series resistor raises doubts about the author's analog design skills. Might be copy-and-past error while modifying an original common drain circuit.
Differential FET amplifier with resistive degeneration (the 500 ohm variable resistor) is a different topic and has nothing in common with the post #1 circuit. If you omit the diode, the output can be bipolar, no need to flip the input wires.
Differential FET amplifier with resistive degeneration (the 500 ohm variable resistor) is a different topic and has nothing in common with the post #1 circuit. If you omit the diode, the output can be bipolar, no need to flip the input wires.