Please if anyone can give me some advice. I need to create a circuit simulating monitoring of a motor speed. I need to do it using op-amps. Input voltage is the output from tachogenerator and vary from 0-15V. reference voltage (represent 4500 rpm) is 9V. I did circut with four LEDs, where green represent voltage less then reference, 1 red between 0-1V over, second between 1-2V, and third one above 2V over reference voltage. It all works, but now I need to improve system to automaticaly switch motor off if speed is over 5500rpm (which is 2V over reference voltage). My question is where I can find DC motor in multisim and how i need to make any safety device for that motor (ideally if it shows speed not voltage, but I dont know if it is possible). below is screenshot of the circuit and multisim file. Hopefully my explanation is understandable. Thanks for you replay.
