LIGHTING CONTROL CIRCUIT, ILLUMINATION LAMP, AND ILLUMINATION DEVICE

摘要

PROBLEM TO BE SOLVED: To save power of an illumination lamp while improving the safety.SOLUTION: A controller 150 of a lighting control circuit of an illumination lamp comprises: a zero-cross detection part 151 that detects a zero-cross timing of an AC signal and outputs a zero-cross signal; a gate signal forming part 155 that is switched as a base point of a zero-cross timing and a timing deviated from the zero-cross timing by a specified phase, thereafter forms a PWM signal switched on the basis of a predetermined duty ratio and set the PWM signal as a gate signal, and controls a switching element on the basis of the gate signal; a subsequent zero-cross timing estimation part 152 that estimates a time when the subsequent zero-cross timing occurs; and a subsequent zero-cross receivable timing formation part 153 that forms a receivable signal indicating a period in which the subsequent zero-cross signal can be received. The gate signal formation part 155 forms the PWM signal in the case where the zero-cross signal is inputted in the period indicated by the receivable signal.SELECTED DRAWING: Figure 9