Function: This voltage regulator is designed for motor speed control and allows adjustment of output voltage using a precision multi-turn potentiometer. Operation: Connect the device in series with a light fixture or household appliance, then turn the knob to control dimming, speed, voltage, and temperature. Performance: The motor speed controller features high-quality thyristors that are resistant to high temperature and high voltage, supporting a maximum current of 25A. Multifunctional: This 220V AC motor speed controller can be used to regulate the speed of AC motors, as well as the brightness of AC lamps and the temperature of heating elements. 1. Equipped with a precision multi-turn potentiometer for adjustable minimum output voltage. 2. Connect the device in series with a lamp or appliance, then rotate the knob to adjust dimming, speed, voltage, and temperature.