AllanBertelsen
New Member
I have been working on a relay/MOSFET motor controller. The diagram shows the circuit without the relay. When I send the PWM signal the LED (D1) clearly shows if duty cycle is hi or low and all in between.
Problem is that I can't recognize any difference in motor speed.
If I measure voltage difference on the output of the opto isolator I see high voltage at low duty cycle and low voltage at high duty cycle. I don't measure any difference in voltage at the motor. It's always high when there is just a small duty cycle. When the PWM signal is of the motor is also off.
I should also mention, that I added a 100 uF cap at the motor supply to reduce noise.
The opto isolator is a PS2501-4.
Problem is that I can't recognize any difference in motor speed.
If I measure voltage difference on the output of the opto isolator I see high voltage at low duty cycle and low voltage at high duty cycle. I don't measure any difference in voltage at the motor. It's always high when there is just a small duty cycle. When the PWM signal is of the motor is also off.
I should also mention, that I added a 100 uF cap at the motor supply to reduce noise.
The opto isolator is a PS2501-4.
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