Title:
ＬＥＤ故障検出装置
Document Type and Number:
Japanese Patent JP5715987
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an LED failure detecting device that can easily detect both disconnection and short-circuiting of LEDs without using any such item as a controller or a memory.SOLUTION: When an LED 1 or an LED 2 of an LED display unit 5 runs into a short-circuiting trouble, current flows to an input terminal of a second B contact relay circuit RL2 of an LED short-circuit detecting circuit 3, and accordingly an output terminal of the same is switched over from an on state to an off state. Then, an A contact relay circuit RL3 of a pseudo-resistance current control circuit 4 is switched over from an on state to an off state, and an output terminal thereof is switched over from an on state to an off state. Since a normal intermittent on/off action current stops flowing to a pseudo-resistance 6 as a result, a winker relay circuit 1 detects the failure of the normal intermittent on/off action current to flow to the pseudo-resistance 6, outputs a trouble notifying action current to notify a user of the occurrence of the trouble, and causes a normal LED to quickly turn on and off.
Inventors:
Hirooka Toshiro
Application Number:
JP2012132035A
Publication Date:
May 13, 2015
Filing Date:
June 11, 2012
Export Citation:
Assignee:
Ishikawa Manufacturing Co., Ltd.
International Classes:
G01R31/02; B60Q11/00; H05B37/03
Domestic Patent References:
| JP2011171547A | ||||
| JP11258300A | ||||
| JP2007015578A | ||||
| JP2002362220A |
Foreign References:
| US20110043114 |
Attorney, Agent or Firm:
Go Eto
Shigeo Nakajima
Shigeo Nakajima