Title:
NOT-TURN-ON DETECTION DEVICE FOR DISCHARGE LAMP
Document Type and Number:
Japanese Patent JP3196251
Kind Code:
B2
Abstract:
PURPOSE: To enable detection of the not-turn-on of a discharge lamp even in the daytime by detecting the turn-on and not-thin-on of the discharge lamp according to changes in the phase and the level of current fed to a ballast which uses as a reference the time at which source voltage becomes zero crossed.
CONSTITUTION: In a turn-off detection device 1 for detecting the not-turn-on of the lamp 3 of a lighting device 2, a current detection means 12 detects the current value between a photoswitch 5 and a ballast 6 after a predetermined time elapses from when a zero cross detection means 11 detects zero cross from a voltage output from a rectifying circuit 9 connected to a power circuit 10. A judging means 13 determines whether the lamp 3 is turned on or not turned on according to the output of a means 12 which uses as a reference the time at which the source voltage becomes zero crossed, and the result of this judgement is displayed in an LED 14. Therefore, the not-turn-on of the lamp 3 can easily be detected even in the daytime and also inspection work can be promptly performed.
Inventors:
Masayuki Morita
Shigeyuki Tokunaga
Akihiro Shibata
Shigeyuki Tokunaga
Akihiro Shibata
Application Number:
JP25179691A
Publication Date:
August 06, 2001
Filing Date:
September 30, 1991
Export Citation:
Assignee:
Toshiba Lighting & Technology Corporation
International Classes:
H05B41/16; (IPC1-7): H05B41/16
Domestic Patent References:
| JP62195898A | ||||
| JP62232896A | ||||
| JP62195897A | ||||
| JP589971A | ||||
| JP5830096A | ||||
| JP5830097A | ||||
| JP1102876U | ||||
| JP6231398U | ||||
| JP58147195U |
Attorney, Agent or Firm:
Takashi Honda