Patent ID: 6522120
Filing Date: 2003-02-18
Classification: H02M

Abstract:
A load driving apparatus, comprising:a power supply for applying power supply voltage; a load circuit configured to be driven by the power supply; a first switch connected to the load circuit and the power supply in series for enabling or disenabling the application of the power supply voltage to the load circuit; a limiting resistor connected to the load circuit in series for dividing the power supply voltage between itself and the load circuit to limit the current supplied to the load circuit; a second switch connected to the limiting resistor in series and connected to the first switch in parallel for enabling or disenabling the application of the power supply voltage to the load circuit and the limiting resistor; and a controller for applying power supply voltage of a plurality of values to the load circuit by opening or closing the first switch and the second switch, thereby controlling a wave form of the power supply voltage supplied to the load circuit.