circuit analysisproteusvoltmeter
I'm really new to Proteus, so if I'm doing something very wrong, sorry.
I'm messing around with the Proteus simulation but I don't understand why my voltmeter has given me a value when the circuit is open. I expected it to give a 0 V result. I tried adding a ground to the negative connection of the Voltage source but it didn't help.
Here is my circuit, with the simulation running:
You have a typo in the line Vi 1 0 SIN ( OV 10V 60Hz ): you wrote OV rather than 0V.
When it's replaced, this circuit simulates correctly (at least under ngspice).
I had exactly the same problem.
Normally, Proteus triggers (energizes) both transistors at "exactly" the same time when the simulation starts. This type of initiation leaves the simulated circuit in a certain "equal" situation. For an A-stable circuit, it is always assumed that the circuit starts with one transistor in the "off" state and the other in the "on" state.
To do this simply add a "switch" to one part of your design. This will be left on the "off" state before you start your simulation. Then turn the switch "on". Everything will go as expected.
Best Answer
I think that's what we call "floating": as long as that wire is connected to nothing, you can't know what happens.
It's quite realistic: if you turn on a multimeter and don't connect the Plus-Pin anywhere, it will show values.
To get around this, you can ensure that this wire is never connected to nothing by adding a resistor in parallel to the meter:
simulate this circuit – Schematic created using CircuitLab