I'm a little new to this, so bear with me:
I am working on a hobby-related project that involves the operation of two DC motors in parallel, powered by a NiMH battery. (Crappy circuit diagram included)
-Battery- NiMH 4000mAH @ 8.4 V DC
-Microswitch - Rated 15A SPDT to toggle motor operation
-Motors - Rated ~6V operation, 11A stall and 0.9A idle
-Wire 16AWG (if relevant)
The battery I have for this project is rated @ 8.4V, whereas the motors are rated for 6 V. I've been looking into finding a way to reduce the voltage to prevent motor damage and remembered PWM from a class I took (I'm an EE undergrad). I figure I could use a PWM circuit to vary the duty cycle in order to prevent motor damage, while conveniently allowing me to alter motor speed with a dial (altering the duty cycle %) without the massive power dissipation a potentiometer would create.
However, I am at a loss as to how to implement such a circuit; the only background on pulse width modulation I have had involve the creation of a basic PWM controller, not on selection and designing one around a circuit.
The circuits I have found online seem like they would work voltage-wise, however when I look at the current ratings they always fall short of the motor stall current. (Example linked)
My question to you is either:
a) How can I make a PWM that is suitable for such a build, or
b) How can I select the right PWM controller to add to the circuit?
Thanks for any insight you can give, please let me know if any more information is needed.
EDIT: It is worth noting that stall current is transient, as the motors reach max rpm, and thus the idle current, fairly quickly. There is occasional slight load on the motors, however it's not enough to be an issue. My only concern would be the hypothetical PWM motor controller having issues with the initial stall current.