Title:
FLUORESCENT LAMP DIMMING CIRCUIT
Document Type and Number:
Japanese Patent JP3259016
Kind Code:
B2
Abstract:
PURPOSE: To provide fluorescent lamp dimming circuits which perform a wide range of dimming from 1/1000 to 1/1 rated lighting without causing brightness unevenness by applying a high AC voltage with a small duty factor to a fluorescent lamp in a low brightness range, and applying a low AC voltage with a large duty factor to the fluorescent lamp in a high brightness range.
CONSTITUTION: Two dimming circuits, i.e., a first dimming circuit consisting of a first pulse control circuit 101 and a first drive circuit 102, and a second dimming circuit consisting of a second pulse control circuit 107 and a second drive circuit 108, are provided. In a low brightness range, a high AC voltage with a small duty factor is applied to a fluorescent lamp 113 by means of an output of the first drive circuit 102 and an output of the second drive circuit 108, while in a high brightness range a low AC voltage with a large duty factor is applied to the fluorescent lamp 113.
Inventors:
Kazuo Yamazaki
Application Number:
JP2530795A
Publication Date:
February 18, 2002
Filing Date:
February 14, 1995
Export Citation:
Assignee:
Japan Aviation Electronics Industry Co., Ltd.
International Classes:
H05B41/24; H05B41/32; H05B41/392; (IPC1-7): H05B41/392; H05B41/24; H05B41/32
Domestic Patent References:
| JP529089A | ||||
| JP6318797U |
Attorney, Agent or Firm:
Kusano Taku (1 person outside)