I am trying to follow a diagram of a NOT gate and replicate it in Proteus.
CMOS NOT gate example diagram:
My CMOS NOT gate in Proteus:
Mine doesn't seem to be working. Can anyone tell me why?
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You have a few things wrong here. Think about which MOSFETS and voltages you are using. Are these power MOSFETs going to give you the results you want with a 5V source and 1V switching voltage? I haven't looked at the datasheet for each but I would suspect not.
Secondly, your volt meters are being used incorrectly. You are just measuring a short circuit. If you want to measure that 1V input signal, you need the voltmeter referenced to GND. As in, the positive side of the meter to signal, and negative to GND. Otherwise it will always show 0V. Look at the example here:
As well as measuring the output wrong, it is also just tied straight to GND. This means when referenced to GND, it will always be 0V. Remove the short on the voltmeter and you will see the actual voltage at this point.
Lastly, your MOSFETs are the wrong way round. You should have the PMOS to the top, with the source connected to VCC, and the NMOS at the bottom with the source connected to GND.
Fix those issues and you'll find the task much easier. Here is an example using generic MOSFETs showing the correct connections for the voltmeters:
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\$\begingroup\$ Of particular note, it looks like @Vladisav is using a PMOS on the bottom and an NMOS on the top, it's hooked up backwards. \$\endgroup\$– effectCommented Aug 12 at 18:14
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1\$\begingroup\$ @effect Yes, you are correct, I did point that out in my original answer, as another (now deleted) answer mentioned it, so I gave credit. I must have deleted the whole paragraph instead of just the credit when editing the answer! \$\endgroup\$– MCGCommented Aug 13 at 15:18