(19)
(11) EP 2 200 406 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
10.09.2014 Bulletin 2014/37

(43) Date of publication A2:
23.06.2010 Bulletin 2010/25

(21) Application number: 09178666.5

(22) Date of filing: 10.12.2009
(51) International Patent Classification (IPC): 
H05B 33/08(2006.01)
B60Q 1/00(2006.01)
B60Q 11/00(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR
Designated Extension States:
AL BA RS

(30) Priority: 18.12.2008 JP 2008322216

(71) Applicant: Koito Manufacturing Co., Ltd.
Tokyo 108-8711 (JP)

(72) Inventors:
  • Matsui, Kotaro
    Shizuoka-shi Shizuoka (JP)
  • Sugiyama, Takao
    Shizuoka-shi Shizuoka (JP)
  • Kitagawa, Takayoshi
    Shizuoka-shi Shizuoka (JP)

(74) Representative: HOFFMANN EITLE 
Patent- und Rechtsanwälte Arabellastrasse 4
81925 München
81925 München (DE)

   


(54) Controller for vehicular lamp


(57) To reduce manufacturing costs by suppressing a ground fault current, a controller for a vehicular lamp includes an inverting converter 2 for supplying power to LEDs 21-1 to 21-n, and a current detection unit 3 that includes a shunt resistor Rs connected serially to the LEDs 21-1 to 21-n and detects an LED driving current flowing through the LEDs 21-1 to 21-n. The current detection unit 3 includes a shunt resistor Rs' connected serially to the LEDs 21-1 to 21-n via the shunt resistor Rs, and a bypass section 4. The bypass section 4 includes an NMOS transistor 10 connected parallel to the shunt resistor Rs' and a Zener diode ZD1 that causes the NMOS transistor 10 to turn off when a ground fault occurs at a positive polarity output side or a negative polarity output side of the inverting converter 2.







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