Led lighting device and led illuminating device

Patent metadata

Field	Value
Publication number	US-2016295657-A1
Application number	US-201615047796-A
Country	US
Kind code	A1
Filing date	Feb 19, 2016
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

An LED lighting device 2 according to this embodiment includes a lighting circuit that supplies a current to an LED, and a dimmer 7 that generates a PWM signal for controlling the supply of the current to the LED from the lighting circuit, in which the dimmer 7 feedback-controls the PWM signal that controls the supply of the current to the LED by comparing the output current to be output to the LED with a target current and feedforward-controls the PWM signal according to a fluctuation of an input voltage from a commercial power supply 1.

First claim

What is claimed is:

1 . An LED lighting device comprising:
a lighting circuit that supplies a current to an LED; and a controller that generates a control signal for controlling the supply of the current to the LED from the lighting circuit, wherein the controller comprises: a feedback control unit that compares the output current to be output to the LED with a target current indicating a predetermined dimming level to feedback-control the control signal so that the LED reaches the predetermined dimming level, and a feedforward control unit that detects a fluctuation of an input voltage from a commercial power supply connected to the lighting circuit to feedforward-control the control signal according to the fluctuation of the input voltage.

2 . The LED lighting device according to claim 1 , wherein:
the control signal is a PWM signal, and the output current to the LED is controlled according to a duty ratio of the PWM signal.

3 . The LED lighting device according to claim 2 , wherein the feedforward control unit multiplies, when the fluctuation of the input voltage occurs, a corrected control signal that is feedback-controlled by the feedback control unit by an inverse number of a rate of fluctuation of the input voltage to change an ON width of the PWM signal.

4 . The LED lighting device according to claim 2 , wherein
when the fluctuation of the input voltage occurs, the feedback control unit generates the PWM signal based on a deviation between the target current and the output current and an integral control element of the deviation, and the feedforward control unit multiplies a corrected control signal generated by the feedback control unit by an inverse number of a rate of fluctuation of the input voltage to change an ON width of the PWM signal and multiplies the integral control element by the inverse number of the rate of fluctuation of the input voltage to update the integral control element.

5 . The LED lighting device according to claim 1 , wherein the lighting circuit has a power factor correction function of the commercial power supply.

6 . An LED illuminating device comprising:
the LED lighting device according to claim 1 ; and an LED supplied with current from the LED lighting device.

Assignees

• Renesas Electronics Corp

Inventors

• Suzuki Motoaki
• Kitamura Mamoru
• Fukuda Keisuke

Classifications

• H05B45/00

  Circuit arrangements for operating light-emitting diodes [LED] · CPC title

• H05B45/37 Primary

  Converter circuits · CPC title

• H05B33/0815

  Electricity · mapped topic

• H05B33/0851 Primary

  Electricity · mapped topic

• H05B45/10 Primary

  Controlling the intensity of the light · CPC title