pid controller – Are the output voltages of each station correct? | Overflow error message when I add feedback
I’m building a PID controller with PSpice For TI2020 and using operational amplifiers.
There is a
VPWL_FILE that outputs 0V for the first second, then 2V thereafter. My controller should react to this “step function” and do what it is supposed to do.
The resulting voltages at the respective output of the individual stations (P, I, D, summing and inverter) look good in my opinion. The gains of the P, I and D components are 1 for test reasons.
I put in a differential amplifier last night to have a way of coupling the circuit’s output to the input. If I just clamped the output between the source and the first op amp, the source just pushes the voltage straight to the output. Hence the idea of using a differential amplifier. I connect the source (V9) (and yes, I know, I’ve tried a lot, that’s why we’re at nine) to one input of the differential amplifier and the output of the controller circuit to the other. I would then connect the output of the differential amplifier to the input of the circuit. On the one hand there is an error message (
overflow, multiply) and on the other hand I can’t imagine that the results are correct.
My question to you is: Do the curves look appropriate to you?
To be more precise: Is it possible that when the step function is still at 0V, the integrator is already outputting -5V? Doesn’t that spoil the overall result?
Source, P, I, D, Summierer, Inverter
my plan to be able to have a feedback loop
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