JPS567076A - Lighting circuit for illuminating battery-operated clock - Google Patents

Lighting circuit for illuminating battery-operated clock

Info

Publication number
JPS567076A
JPS567076A JP8287979A JP8287979A JPS567076A JP S567076 A JPS567076 A JP S567076A JP 8287979 A JP8287979 A JP 8287979A JP 8287979 A JP8287979 A JP 8287979A JP S567076 A JPS567076 A JP S567076A
Authority
JP
Japan
Prior art keywords
lighting
brightness
transistor
circumstances around
power consumption
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP8287979A
Other languages
Japanese (ja)
Inventor
Yoshihiro Sakurai
Ryusuke Nakanishi
Hidetoshi Kasai
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP8287979A priority Critical patent/JPS567076A/en
Publication of JPS567076A publication Critical patent/JPS567076A/en
Pending legal-status Critical Current

Links

Landscapes

  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

PURPOSE: To prevent unnecessary power consumption by controlling a lighting element for operation according to a brightness of the circumstances around.
CONSTITUTION: A resistance of a light detector 3 forming a photoconductive element like CdS gets large and a switching transistor 5 is conducting in accordance as a brightness of the circumstances around becomes a given level or below, and thus a lighting element LED2 lights up. A lighting is therefore effective only when the brightness of the circumstances around is kept at a given level or below, which is to prevent unnecessary power consumption for lighting, thereby ensuring a supply battery 4 for longer life. Further, from connecting a transistor with base current fixed at a given value in series to the transistor, the lighting element is driven at a constant current to keep a lighting liminance constant, and a longer life can be ensured for the supply battery accordingly.
COPYRIGHT: (C)1981,JPO&Japio
JP8287979A 1979-06-30 1979-06-30 Lighting circuit for illuminating battery-operated clock Pending JPS567076A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8287979A JPS567076A (en) 1979-06-30 1979-06-30 Lighting circuit for illuminating battery-operated clock

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8287979A JPS567076A (en) 1979-06-30 1979-06-30 Lighting circuit for illuminating battery-operated clock

Publications (1)

Publication Number Publication Date
JPS567076A true JPS567076A (en) 1981-01-24

Family

ID=13786557

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8287979A Pending JPS567076A (en) 1979-06-30 1979-06-30 Lighting circuit for illuminating battery-operated clock

Country Status (1)

Country Link
JP (1) JPS567076A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61204054U (en) * 1985-06-13 1986-12-22
JPS63195285U (en) * 1987-06-05 1988-12-15
KR20040029503A (en) * 2002-10-01 2004-04-08 이범진 Apparatus for confirming lighting of lamp in bathroom

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61204054U (en) * 1985-06-13 1986-12-22
JPH0447487Y2 (en) * 1985-06-13 1992-11-10
JPS63195285U (en) * 1987-06-05 1988-12-15
KR20040029503A (en) * 2002-10-01 2004-04-08 이범진 Apparatus for confirming lighting of lamp in bathroom

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