Patent ID: 8604770
Filing Date: 2013-12-10
Classification: H05B

Abstract:
1. A load drive device comprising: a converter circuit for controlling an electric power by performing PWM (Pulse Width Modulation) control, an output circuit for turning on or off the electric power supplied to a load according to a burst signal, a comparison circuit for comparing a duty cycle of said burst signal with a reference value, and a control value generating circuit for outputting a control value generated based on a detected value obtained by detecting a state of the load to said output circuit when said burst signal is active and said output circuit supplies the electric power if a duty ratio of said burst signal is not smaller than said reference value, and a previous value correcting circuit for outputting said control value obtained by correcting a previous value of said control value to said output circuit when said burst signal is active and said output circuit supplies the electric power if a duty ratio of said burst signal is smaller than said reference value, a PWM circuit for generating a pulse drive signal for operating said PWM control by inputting said control value from said output circuit, wherein said PWM circuit determines a duty cycle of PWM based on said control value output from said control value generating circuit or said previous value correcting circuit.