Trex whiny motors

I’m using the Trex to drive 2 12 volt motors but there making a high pitched whine at slow speeds. What is the default PWM frequency and can I change it? Any other suggestions?

Hello.

Which TReX are you using, the TReX or the TReX Jr? The default frequencies are 19.5 kHz and 2.44kHz, respectively. You can change the PWM frequency of both, but only the TReX (not the TReX Jr.) allows you to set the frequency high enough to be outside the typical range of human hearing. You can find more information on setting the PWM frequency in the “PWM Prescaler” section of the TReX configuration parameter documentation and the TReX Jr configuration parameter documentation, which can be found under the “Resources” tab on their product page.

- Jeremy