Title:
照明電源装置用の調光制御回路および調光制御プログラム
Document Type and Number:
Japanese Patent JP6480792
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a dimming control circuit for lighting power supply device which is capable of reducing calculation error of a duty ratio of a PWM signal for dimming and has excellent responsiveness with respect to a dimming knob.SOLUTION: A dimming control circuit 10 comprises a microcontroller (MCU) which receives a PWM signal for dimming and generates a command voltage V2 for controlling an LED current in accordance with the PWM signal. In the MCU, a rising edge interval of the PWM signal is counted, and its term t0 is obtained, and an interval between a rising edge and a falling edge is counted and a high level term t1 is obtained. Next, a digital signal of a ratio (t1/t0) thereof is normalized into a digital signal X having the number of bits of the MCU or the number of bits that is smaller than the number of bits of the MCU just by several bits. Further, the normalized digital signal X is digitally converted into the command voltage V2 of the LED current based on a conversion table of the MCU, and outputted as a voltage signal via a D/A converter.SELECTED DRAWING: Figure 1
Inventors:
Minoru Matsumoto
Application Number:
JP2015083108A
Publication Date:
March 13, 2019
Filing Date:
April 15, 2015
Export Citation:
Assignee:
Eye Lighting System Co., Ltd.
International Classes:
H05B37/02
Domestic Patent References:
| JP2014203631A | ||||
| JP2015041431A | ||||
| JP2015041430A |
Attorney, Agent or Firm:
Yuji Iwahashi
Shinji Kato
Shinji Kato