(19)
(11) EP 2 525 627 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
09.07.2014 Bulletin 2014/28

(43) Date of publication A2:
21.11.2012 Bulletin 2012/47

(21) Application number: 12167157.2

(22) Date of filing: 08.05.2012
(51) International Patent Classification (IPC): 
H05B 33/08(2006.01)
(84) Designated Contracting States:
AL 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 RS SE SI SK SM TR
Designated Extension States:
BA ME

(30) Priority: 18.05.2011 JP 2011111598

(71) Applicant: Panasonic Corporation
Osaka 571-8501 (JP)

(72) Inventors:
  • Kado, Yoshikazu
    Suita, Osaka (JP)
  • Kumada, Kazuhiro
    Himeji, Hyogo (JP)
  • Nagata, Satoru
    Osaka 540-6207 (JP)
  • Nishimoto, Kazuhiro
    Kashirhara, Nara (JP)

(74) Representative: Rüger, Barthelt & Abel 
Webergasse 3
73728 Esslingen
73728 Esslingen (DE)

   


(54) LED power source device


(57) [Object] To provide an LED power source device able to prevent an excessive current to an LED.
[Means for Settlement] An LED power source device 10 includes: a rectifier DB; an output power source adjustment circuit 13 for supplying electric power to an LED 12; a drive circuit 14; a stop control circuit 16 for judging existence and nonexistence of the LED 12 by detecting an electric current flowing to the LED 12 and for operating to stop the drive circuit 14 upon detection of the nonexistence of the LED 12; and a mask circuit 17 for monitoring the voltage after the rectification to control the stop control circuit 16, wherein in the case where the voltage after the rectification is a predetermined value or less of the mask circuit 17, the operation of the stop control circuit 16 is not prohibited.







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Search report