It is if you limit the PWM to no more than about 50% duty-cycle steady-state, or limit the motor current to 6A (if 6A is the maximum steady-state motor current rating).Can I run a 6V 6A DC motor with PWM and power it with 12V power supply?
Is this safe for the motor ?
The impression I get is; the TS is wondering about applying 12V to a 6V motor at no more than 50% duty cycle - if the pulse repetition rate is high enough, the motor's inductance will protect it.I would also use a fuse to protect the motor in case the PWM circuit fails continuously on giving a 100% duty cycle.
At 36kHz, there may even be too much inductive reactance in the motor to get its full rated torque at 12V on high duty cycle.In fact I was planning to use this circuit
View attachment 90324
Where the PWM frequency is around 36kHz. But I'm bit worried that the engine will not withstand this 12V at 50% duty cycle and will overheat and burn.
The 'Overheat' will not be as a result of voltage, but torque/load/current, 50% duty cycle on its own does not mean much.In fact I was planning to use this circuit
View attachment 90324
Where the PWM frequency is around 36kHz. But I'm bit worried that the engine will not withstand this 12V at 50% duty cycle and will overheat and burn.
The motor inductance acts like a filter to the PWM frequency, giving a DC current proportional to the average DC voltage from the PWM. A high inductance does not affect that fact.At 36kHz, there may even be too much inductive reactance in the motor to get its full rated torque at 12V on high duty cycle.
Because of the motor inductance the 12V peak of the PWM will not cause high peak currents, so the motor won't overheat.................
Where the PWM frequency is around 36kHz. But I'm bit worried that the engine will not withstand this 12V at 50% duty cycle and will overheat and burn.