This 12V – 40V 10A  13KHZ PWM DC Motor Speed Controller Module is a motor governor whose input is DC and cannot be directly connected to the AC (for example home 220V AC), otherwise it will burn! DC power supply positive and negative terminals do not reverse, otherwise the governor may be damaged.

The motor can be positive or negative, when the direction of operation and expectations do not match, you can adjust the line order to change the direction.

Adjust the potentiometer knob to change the governor output duty cycle, The motor speed changes.