Is it smart , necessary, or even possible to use a Pololu 15 Amp high-power motor driver and a digital PWM Motor Speed Controller (50A) with a Arduino to control the speed and shaft rotation of a 24 V 350 W motor?
I want to be able to keep the current down in order to satisfy the motor driver, but I also need the motor controller to decrease the rpms of the shaft by limiting frequency. I planned to put two 12 volt batteries in series to decrease the current. But is this necessary? Would I even need the motor controller? I would like for the motor driver to somehow control the speed and direction of the rotation of the motor's shaft.
I planned to put two 12 volt batteries in series to decrease the current.
In series with the motor surly I am misunderstanding you here or you are not understanding a big something.
PWM will only reduce the motor speed if the motor is under load, an unloaded motor shows little speed reduction, so the speed / PWM relationship only holds for a fixed load.
If you're not going to be reversing the motor very much/fast, you could use a relay to do that part. Then you'd only need a very simple (and much less expensive) controller for speed.
You need to be very careful about "peak" and "average" current ratings: many motor controllers (especially ones sold to hobbyists) are rated in terms of the amount of current they can handle for very short peaks. If you're going to be running the motor for longer periods (e.g., running a robot, rather than moving a camera mount or robot arm in short bursts), you might need a stronger controller. Also, motors often draw much more than their "average" ratings when they're under heavy load (like when accelerating from a standing start, or when the mechanism is stalled by bumping into something). So you may need a heftier controller than you think.
The Pololu parts based on the VNH2SP30 will not handle a voltage higher than 12 volts nominal. This is one of their greatest limitations and is a side effect of their incredibly low LDSON. Check the datasheets carefully.
If you need more voltage, I think you will need a different part.
If you're not going to be reversing the motor very much/fast, you could use a relay to do that part.
What type of relay would I need and how would I go about hooking this up?
To clarify, I am in the process of building a sliding gate. So it just consist of a motor rotating clockwise for about 10 seconds in one direction, remaining put, and then rotate counter clockwise in the other direction.