DC motor input voltage control


Thread Starter


Need help in designing a circuit that would help me control the input current to a motor without using Pulse width modulation. The reason for current control being i am designing a vehicle which follows a signal on a path which includes hills and bends If anyone has a circuit that works i would be grateful

Robert Scott

I see no reason why you cannot use PWM. When the switching frequency is high enough, the current through the motor is nearly constant anyway, so the effect is the same as if you used some non-switching technology. You could use straight linear current regulation with high-power FETs, but then you would burn up as much power in the FETs as is being consumed by the motor - very inefficient and expensive.

You can achieve closed-loop current control using PWM if you measure the current and feed back to the duty cycle.