Title:
DIMMING CIRCUIT FOR LED POWER SUPPLY
Document Type and Number:
Japanese Patent JP2019057427
Kind Code:
A
Abstract:
To provide a technology for improving stability in dimming control of an LED power supply, particularly, an LED lamp.SOLUTION: Provided is a dimming circuit 18 for stably controlling a switching power supply device 10 that supplies a power to an illumination load 20. The dimming circuit 18 includes: an MCU 30 that outputs a dimming signal from the exterior as a rectangular wave; an LC rectification circuit 32 that converts the rectangular wave outputted from the MCU 30 into a DC reference voltage; and a step-down control circuit 34 that controls an on-off operation of a switching element Q1 included in the switching power supply device 10. The LC rectification circuit 32 comprises an impedance conversion circuit 36 that increases an input impedance of the LC rectification circuit 32. The step-down control circuit 34 switches between PWM control and PFM control to control the switching element Q1. The reference voltage is a DC voltage including sine wave ripples.SELECTED DRAWING: Figure 1
Inventors:
MATSUMOTO MINORU
OSATO TOMOKAZU
UMEZAWA YOSHIHISA
OSATO TOMOKAZU
UMEZAWA YOSHIHISA
Application Number:
JP2017181302A
Publication Date:
April 11, 2019
Filing Date:
September 21, 2017
Export Citation:
Assignee:
EYE LIGHTING SYST CORP
International Classes:
H05B37/02
Attorney, Agent or Firm:
Yuji Iwahashi
Shinji Kato
Shinji Kato