Patent ID: 6678177
Filing Date: 2004-01-13
Classification: H02M,H02P

Abstract:
A method for driving a bridge circuit for driving an inductance load, comprising:the bridge circuit having: a first circuit having a first pair of switching elements arranged in series; a second circuit having a second pair of switching elements arranged in series; a first connecting point for connecting the first circuit and the second circuit; the first connecting point connected to a power supply; a second connecting point for connecting the first circuit and the second circuit; the second connecting point connected to a ground; an inductance load connected to an intermediate connecting point between the first pair of switching elements of the first circuit and an intermediate connecting point between the second pair of switching elements of the second circuit; and flywheel diodes connected to the respective switching elements in parallel; the method for driving the bridge circuit for driving the inductance load in response to a pulse width modulation signal which modulates a control signal with a sine wave by the pulse width modulation, and including a means for turning OFF one of the switching elements on either an upper arm of the bridge circuit connected to the power supply or a lower arm thereof connected to the ground and for turning ON the other one of the switching elements on the same arm thereof when the pulse width modulation signal is OFF under the state where a phase difference occurs between an electric current of the control signal with the sine wave and a voltage and where a polarity of the electric current differs from a polarity of the voltage, wherein the electric current is circulated via the other one of the switching elements, the flywheel diode connected to the one of the switching elements, and the inductance load.