Maximum voltage applied to motor shield

Hi,

I am doing a project with stepper motor. The problem I have now is the stepper motor needs 24V. However, I tried to apply 20V to the motor shield, then the Arduino Uno board underneath the motor shield got burnt. I found the maximum voltage the motor shield can take is 18V, is there a way to solve this problem. Thanks

Which motor, which motor shield?

Be careful. If your motor shield doesn't limit the current to the motor you may also fry the motor.

If your stepper motor has a sufficient coil resistance so that it can't exceed its maximum current at 24v everything will be fine. However many stepper motors are driven at 24v with current limiting drivers (such as the Pololu A4988) because their coil resistance is designed for a much lower voltage.

...R