GB1484803A - Electronic flash unit - Google Patents

Electronic flash unit

Info

Publication number
GB1484803A
GB1484803A GB3222775A GB3222775A GB1484803A GB 1484803 A GB1484803 A GB 1484803A GB 3222775 A GB3222775 A GB 3222775A GB 3222775 A GB3222775 A GB 3222775A GB 1484803 A GB1484803 A GB 1484803A
Authority
GB
United Kingdom
Prior art keywords
thyristor
tube
flash
capacitor
lamp
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
GB3222775A
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.)
Rollei Werke Franke und Heidecke GmbH and Co KG
Original Assignee
Rollei Werke Franke und Heidecke GmbH and Co KG
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 Rollei Werke Franke und Heidecke GmbH and Co KG filed Critical Rollei Werke Franke und Heidecke GmbH and Co KG
Publication of GB1484803A publication Critical patent/GB1484803A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14Circuit arrangements
    • H05B41/30Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp
    • H05B41/32Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp for single flash operation
    • H05B41/325Circuit 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)

Abstract

1484803 Electronic flash units FRANKE & HELDECKE GmbH 1 Aug 1975 [10 Aug 1974] 32227/75 Heading G2A An electronic flash unit comprises a flash tube 2 in series with a thyristor 3, a flash measuring device 16 for blocking the thyristor 3 after receipt of a predetermined quantity of light from the tube 2, a capacitor 12 connected in parallel with the thyristor 3 so as to charge during the time between blocking of the thyristor 3 and quenching of the tube 2 and means, preferably a lamp 15, to indicate when the charge on capacitor 12 reaches a predetermined level lighting up of lamp 15 thus indicates that device 16 has worked properly. When thyristor 3 is turned on again for the next flash, capacitor 12 discharges through it, if it hasn't already discharged through resistors 13, 14, so that lamp 15 is extinguished and ready for use again. In Fig. 1 the ignition circuit 5 to 8 ignites tube 2 and thyristor 3 simultaneously. In Fig. 2 (not shown) the tube (22) is ignited first, and the resulting voltage pulse through capacitors (29, 33) turns on the thyristor (23). In this circuit a resistor (32) has to be connected in parallel with the thyristor (32) and as a consequence diodes (37, 42) are connected in the charging and discharging paths of the lamp control capacitor (38). A prior art arrangement is described in which the flash tube is short circuited by a quench tube which lights up for a few milliseconds, light being transmitted from the quench tube to a fluorescent disc by a light pipe for indication purposes. The afterglow of.the disc makes this indicator arrangement ineffective when a rapid succession of flashes is used.
GB3222775A 1974-08-10 1975-08-01 Electronic flash unit Expired GB1484803A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19742438541 DE2438541B2 (en) 1974-08-10 1974-08-10 ELECTRON FLASH DEVICE

Publications (1)

Publication Number Publication Date
GB1484803A true GB1484803A (en) 1977-09-08

Family

ID=5922929

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3222775A Expired GB1484803A (en) 1974-08-10 1975-08-01 Electronic flash unit

Country Status (4)

Country Link
JP (1) JPS5142531A (en)
DE (1) DE2438541B2 (en)
GB (1) GB1484803A (en)
HK (1) HK10981A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5384349U (en) * 1976-12-14 1978-07-12
JPS5410728A (en) * 1977-06-25 1979-01-26 Sunpak Kk Device for confirming lighttadjustment operation in lighttadjusting strobo
JPS5636635A (en) * 1979-08-31 1981-04-09 Canon Inc Dimming check display device in dimming strobe

Also Published As

Publication number Publication date
HK10981A (en) 1981-04-03
DE2438541B2 (en) 1977-12-22
JPS5142531A (en) 1976-04-10
DE2438541A1 (en) 1976-02-19

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee