CONSTANT CURRENT CONTROL POWER SUPPLY, CONSTANT CURRENT CONTROL METHOD, AND CONSTANT CURRENT CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress abrupt variation of the average output current in a constant current control power supply which performs PWM control, a constant current control method, and a constant current control device.SOLUTION: A constant current control power supply 1 which outputs constant current has: a switch element Q; a control circuit 120 which controls the switch element Q to control constant current; and a control section 10 which outputs a PWM signal to the control circuit 120. The control circuit 120 controls the switch element Q in the average current mode in accordance with the current flowed into the switch element Q and controls the switch element Q by PWM control in accordance with the PWM signal. The control section 10 decreases frequency of the PWM signal when a duty ratio of the PWM signal is changed from 100% and when the duty ratio of the PWM signal is changed to be 100%.