GB1292373A - Electronic flash circuit - Google Patents

Electronic flash circuit

Info

Publication number
GB1292373A
GB1292373A GB9377/70A GB937770A GB1292373A GB 1292373 A GB1292373 A GB 1292373A GB 9377/70 A GB9377/70 A GB 9377/70A GB 937770 A GB937770 A GB 937770A GB 1292373 A GB1292373 A GB 1292373A
Authority
GB
United Kingdom
Prior art keywords
thyristor
flash
capacitor
circuit
tube
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.)
Expired
Application number
GB9377/70A
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.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries 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 Philips Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1292373A publication Critical patent/GB1292373A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/30—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp
    • H05B41/32—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp for single flash operation
    • H05B41/325—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp for single flash operation by measuring the incident light

Landscapes

  • Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)
  • Stroboscope Apparatuses (AREA)
  • Exposure Control For Cameras (AREA)

Abstract

1292373 Electronic flash circuit PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 26 Feb 1970 [1 March 1969] 9377/70 Heading G1A [Also in division G2] In an electronic flash circuit provided with an electronic flash-tube 5 and a photo-sensitive element 7, the duration of the flash is influenced by the quantity of light which is reflected on to the photo-sensitive element by the object to be photographed. The supply circuit of the flash-tube 5 includes two parallelly arranged thyristors 4, 9 each of which is connected to its own supply capacitor 3, 10, capacitor 10 having smaller capacity than capacitor 3. On ignition by switch 6 the thyristor 4 conducts and thyristor 9 is subsequently rendered conducting when the photosensitive element 7 has received a predetermined quantity of light. Owing to the higher potential of the capacitor 10, the thyristor then takes over the supply of current to the flash-tube 5 from the circuit containing the thyristor 4. The circuit is such that the period during which current flows through thyristor 9 and discharges condenser 10 is longer than the recovering time of the thyristor 4, so that the thyristor 4 is blocked and the direct current supply to the flash-tube 5 from the capacitor 3 is interrupted.
GB9377/70A 1969-03-01 1970-02-26 Electronic flash circuit Expired GB1292373A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691910544 DE1910544B2 (en) 1969-03-01 1969-03-01 ELECTRONIC FLASHLIGHT DEVICE WITH FLASH TUBE DISCHARGE CONTROLLED BY THE BRIGHTNESS OF THE RECORDING OBJECT

Publications (1)

Publication Number Publication Date
GB1292373A true GB1292373A (en) 1972-10-11

Family

ID=5726853

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9377/70A Expired GB1292373A (en) 1969-03-01 1970-02-26 Electronic flash circuit

Country Status (7)

Country Link
US (1) US3790847A (en)
JP (1) JPS4831621B1 (en)
BE (1) BE746703A (en)
DE (1) DE1910544B2 (en)
FR (1) FR2033094A5 (en)
GB (1) GB1292373A (en)
NL (1) NL160142C (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5979233A (en) * 1982-10-28 1984-05-08 Canon Inc Flash device

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3238419A (en) * 1962-06-07 1966-03-01 Gen Electric Electrical protective circuit
US3376470A (en) * 1965-08-12 1968-04-02 Atomic Energy Commission Usa Capacitor discharge circuit for starting and sustaining a welding arc
US3591829A (en) * 1967-04-20 1971-07-06 Minolta Camera Kk Automatic control device for electronic flash
US3497768A (en) * 1968-03-05 1970-02-24 Addressograph Multigraph One shot operation circuit for a gas discharge lamp
DE1764204B1 (en) * 1968-04-23 1972-01-05 Bosch Photokino Gmbh ELECTRONIC BLOCKING UNIT

Also Published As

Publication number Publication date
NL160142B (en) 1979-04-17
US3790847A (en) 1974-02-05
FR2033094A5 (en) 1970-11-27
JPS4831621B1 (en) 1973-10-01
NL7002788A (en) 1970-09-03
DE1910544A1 (en) 1970-12-17
NL160142C (en) 1979-09-17
BE746703A (en) 1970-08-27
DE1910544B2 (en) 1972-01-13

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee