Control the Amps on the 10A DC Motor Driver Shield

Other Hardware Motors, Mechanics, Power and CNC
1

Using this motor driver shield ( Cytron 10A DC Motor Driver Arduino Shield ).

Is it possible to control (either from Arduino or from the shield) the max Amps going to the motor?
I would like to perform some tests at a lower torque, without purchasing a dozen power supplies.
The current power supply outputs 5A (12V), the motor eats 3A max.
I'd like, from time to time, to limit that output to 0.5, 1, or 2 A.
Ideally, would that be programmable...

2

inokashira:
Using this motor driver shield ( Cytron 10A DC Motor Driver Arduino Shield ).

Is it possible to control (either from Arduino or from the shield) the max Amps going to the motor?
I would like to perform some tests at a lower torque, without purchasing a dozen power supplies.
The current power supply outputs 5A (12V), the motor eats 3A max.
I'd like, from time to time, to limit that output to 0.5, 1, or 2 A.
Ideally, would that be programmable...

Use a rheostat, a power handling variable resistor in series with the motor. That will increase the resistance and reduce the current. Use Ohms law to compute the resistance needed. You can also use an adjustable wire-wound resistor to do the same thing, just not quickly adjustable.
Paul

3

Thanks. I thought about a resistance, but that would yield (for going, at 12V from currently 2A to 1A) 6Ω.
Not used to that kind of resistance, but at that low Ω it'll get warm quick, no?

4

inokashira:
Thanks. I thought about a resistance, but that would yield (for going, at 12V from currently 2A to 1A) 6Ω.
Not used to that kind of resistance, but at that low Ω it'll get warm quick, no?

So?

5

For torque control you need a driver that is able to control current - most cheap H-bridges don't allow this,
as it requires more components.

You could implement a control loop to set the current, if you add a suitable current sensor - the Arduino can use
a PID loop to drive the PWM to force the current to match the set point. Not a trivial task though.

Rheostat is a stop-gap solution, and expensive at higher power ratings, as well as bulky. You won't get
precise current limiting with a series resistor, but crude limiting with poorer speed control.

And if you go the extra power supply route, I'd suggest a fully adjustable lab power supply with voltage and
current limit presets - this will be useful for many projects.