Motor Problem

userHead Account cancelled 2011-09-22 17:16:59 5714 Views2 Replies
Hi Guys
I have purchased these DC motors:
and the following motor driver:

Both are DFRobot products.

The motors do not work well with PWM. They make a "whistling" noise when i send a PWM signal of 255. My entire project revolves around speed control, thus the reason i bought the 2A motor driver since it seems robust to noise etc...

I wrote a small program which spins the wheels for 5 seconds when the user pushes a button. The program works with LEDs on a seperate circuit, but when i connect the motor driver and motors then the motors do not spin. They just "whistle" I am applying a voltage of 4.6V to the motor driver. I want to run the motors at 3V because i want them to move very slowly.

Any idea how i can eliminate the whistling sound and get my motors to spin with accurate pwm control using this particular motor driver and dc geared motor?
2011-09-28 16:24:57 Also, the pwm frequency will be a source for the noise. But we have played with these motors quite a lot and we know that they work with our drivers. userHeadPic R2D2C3PO
2011-09-23 10:08:01 Hi Yuveer,

The whistling noise is natural for these motors. The gearbox makes this noise. You should supply more voltage in order for the motors to move. The recommended voltage you should supply is 8volts. the speed will be controlled by the PWM. If you do not supply enough voltage, when you add a load to the motor it will be too weak to turn. I suggest you try adding more voltage and scaling down through trial and error until you achieve a good balance where you are satisfied.

userHeadPic Hector