next topic »

[on:]

My DC motor is rated from 1.5v to 3v. I have an 11.1 volt battery to run the motor off of.  I have looked for a voltage regulator, but I can't find one that can handle the current (< 1.A).  Is it safe to run this directly off of the 11.1v source?

On a side not when I hook the motor up to a variable power supply it only lets me apply 4volts to it?

[Reply #1 on:]

If you use a motor driver that has an enable/PWM input you can use PWM (pulse-width modulation) to run the motor at a lower effective voltage. This is much more efficient than using a voltage regulator.

If your motor is rated for 3V then the maximum PWM duty cycle should be about 3/11.1 = 27%. Using the analogWrite() function to generate PWM means you should call this function with values analogWrite(0) (motors off) to analogWrite(69) (about 27% of 255, the maximum value).

--
The Rugged Motor Driver: two H-bridges, more power than an L298, fully protected

[Reply #2 on:]

On a side not when I hook the motor up to a variable power supply it only lets me apply 4volts to it?

That is probably because the motor is trying to take more current than the supply can give so the current limit of the supply kicks in and lowers the voltage.