Amplifying a 12 volt pwm signal

Is there any off the shelf circuit that can take a 12 volt low current pulse width signal and make it a high current signal? Basically I have a one amp 12volt output and would like to run a 15-20 amp motor. Microtrak make what they call a motor drive module that does this but is expensive. I know this isn’t exactly an agopengps question but I have found a lot of good ideas on this site for various sensor and controllers.

I think of DC-DC SSR relay, another way is a high current mosfet circuit.


Or it can be a solution with optocoupler, or if the 12 volts is reduced to 5 volts, and the 5 volt pwm signal is applied to the input of the BTS7960 B driver, a 15-20 amp dc motor can be controlled at the motor driver output.



Looks like SSR relay may worked. I have looked at those before but it never occurred to me that you could have a PWM input. Any potential pitfalls of using an SSR relay with PWM?

There is already an optocoupler in the internal structure of the SSr relay, generally large AC devices are controlled with low DC voltages, I think DC-DC solid state relay (SSR) will work, but it would be nice if more professional friends could answer.

Possibly an off-the-shelf, half-bridge motor driver would work, like the cytron. I’ve seen drives capable of 30 amps for sale. With a suitable resistor the 12v input would drive the pwm input, depending on how it’s built. If it’s an optocoupler a small additional resistance (depending on the LED in the coupler used, a few hundred ohms would work) would allow the 12v to feed the optocoupler input. Some mosfet driver ICs can already handle 12v logic directly, which would make it even easier.

But if the SSR can handle the frequency, then that works just as well.

1 Like