I have these small dc TAMIYA motors rated at 3v at around 2-3 amps. I also have a driver that I'm planning to use to drive the motor.
I could not find any other driver that has a very low minimum voltage at a high current.
As you can see the driver has a minimum input of 6.5v, I am aware that over voltage can reduce the lifespan of the motor, but I don't mind since there are a bunch of these motors here collecting dust.
At 6.5v motor does not spin (which is weird). Upon raising it to 7.5 it now spins, very very fast. So I lowered the PWM to 5% (I'm using an Arduino analogWrite with a value of 10) and slowly increased to more suitable RPM.
Now as am playing with the voltage I noticed that the motor loses torque as I increased its voltage.
Why is this happening ??
Also, while as I was playing with the PWM I also noticed that the torque also peaks at a certain PWM. Like at 10% the torque peaks, above and below values is just weaker.
Can anybody please help explain?
Another observation i have just noticed is that the driver gives out 7v, upon connecting to the motor the motor spins weakly. but upon upon connecting the motor to direct 7v it is much stronger in torque and speed