GB1343563A - Quench triggering circuit for an electronic flash photographic system - Google Patents

Quench triggering circuit for an electronic flash photographic system

Info

Publication number
GB1343563A
GB1343563A GB1527772A GB1527772A GB1343563A GB 1343563 A GB1343563 A GB 1343563A GB 1527772 A GB1527772 A GB 1527772A GB 1527772 A GB1527772 A GB 1527772A GB 1343563 A GB1343563 A GB 1343563A
Authority
GB
United Kingdom
Prior art keywords
circuit
voltage
flash
signal
quench
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
GB1527772A
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.)
Honeywell Inc
Original Assignee
Honeywell Inc
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 Honeywell Inc filed Critical Honeywell Inc
Publication of GB1343563A publication Critical patent/GB1343563A/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
    • 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

Landscapes

  • Stroboscope Apparatuses (AREA)

Abstract

1343563 Electronic flash control circuits HONEYWELL Inc 4 April 1972 [15 April 1971] 15277/72 Heading G2A A flash photographic system has a quench triggering circuit comprising a light integrating circuit R8, C7, a threshold circuit including a reactance C6 which is charged to generate a rising threshold signal, a comparison circuit which generates a quench signal when the signal from the light integrating circuit exceeds the threshold signal, wherein, to prevent the threshold signal falling as the supply voltage falls, the reactance is charged via a non-linear circuit which provides regulated charging and a voltage responsive circuit for reducing the effect of changes in supply voltage on the magnitude of the threshold signal. Switch S1 is closed upon the opening of the camera shutter, and this initiates a flash, Fig.1B. The reflected light is incident upon LASCRI and a current representative of the amount of light flows through its gate terminal to charge C7. Eventually the voltage on C7 exceeds that on C6, the thyristor LASCRI fires, the voltage between terminals 12, 13 drops to near zero and the flash is terminated. Reactance C6 is charged via a transistor Q 3 which is turned on via zener diode ZD3 when the flash is initiated. If supply voltage across terminals 12, 13 decreases then transistor Q 3 will be cut-off, and the voltage on C6 will charge towards the decaying anode voltage of LASCRI, preventing the generation of a false quench trigger signal. The accuracy of the circuit is enhanced by the inclusion of a temperative responsive resistor R9.
GB1527772A 1971-04-15 1972-04-04 Quench triggering circuit for an electronic flash photographic system Expired GB1343563A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US13421471A 1971-04-15 1971-04-15

Publications (1)

Publication Number Publication Date
GB1343563A true GB1343563A (en) 1974-01-10

Family

ID=22462281

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1527772A Expired GB1343563A (en) 1971-04-15 1972-04-04 Quench triggering circuit for an electronic flash photographic system

Country Status (4)

Country Link
US (1) US3793556A (en)
CA (1) CA953773A (en)
DE (1) DE2217270A1 (en)
GB (1) GB1343563A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1727400A1 (en) * 2001-05-02 2006-11-29 Fuji Photo Film Co., Ltd. Flash device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914647A (en) * 1974-03-29 1975-10-21 Honeywell Inc Light sensor for use with electronic flash units
US4085353A (en) * 1976-03-11 1978-04-18 Rollei Of America, Inc. Remote sensor trigger circuit

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3591829A (en) * 1967-04-20 1971-07-06 Minolta Camera Kk Automatic control device for electronic flash
DE1772129A1 (en) * 1968-04-03 1971-11-11 Bosch Elektronik Gmbh Electronic flash unit
US3519879A (en) * 1968-07-25 1970-07-07 Honeywell Inc Flash apparatus with automatic light termination having gating and anticipation means

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1727400A1 (en) * 2001-05-02 2006-11-29 Fuji Photo Film Co., Ltd. Flash device

Also Published As

Publication number Publication date
DE2217270A1 (en) 1972-10-26
CA953773A (en) 1974-08-27
US3793556A (en) 1974-02-19

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PLNP Patent lapsed through nonpayment of renewal fees