GB1292373A - Electronic flash circuit - Google Patents
Electronic flash circuitInfo
- 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
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.
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)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5979233A (en) * | 1982-10-28 | 1984-05-08 | Canon Inc | Flash device |
Family Cites Families (5)
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 |
-
1969
- 1969-03-01 DE DE19691910544 patent/DE1910544B2/en not_active Ceased
-
1970
- 1970-02-24 US US00013373A patent/US3790847A/en not_active Expired - Lifetime
- 1970-02-26 NL NL7002788.A patent/NL160142C/en not_active IP Right Cessation
- 1970-02-26 FR FR7006912A patent/FR2033094A5/fr not_active Expired
- 1970-02-26 JP JP45015968A patent/JPS4831621B1/ja active Pending
- 1970-02-26 GB GB9377/70A patent/GB1292373A/en not_active Expired
- 1970-02-27 BE BE746703D patent/BE746703A/en not_active IP Right Cessation
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 |