voltage controller
... that a voltage controller is a device which dims street lights, controls the temperature of heating at home, and controls the speed of motors?
... that a <b id="mwBJk"><a href="./Voltage_controller" id="mwBJo" rel="mw:WikiLink" title="Voltage controller">voltage controller</a></b> is a device which dims street lights, controls the temperature of heating at home, and controls the speed of motors?