GB1343563A - Quench triggering circuit for an electronic flash photographic system - Google Patents
Quench triggering circuit for an electronic flash photographic systemInfo
- 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
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.
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)
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)
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)
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 |
-
1971
- 1971-04-15 US US00134214A patent/US3793556A/en not_active Expired - Lifetime
-
1972
- 1972-02-24 CA CA135,498A patent/CA953773A/en not_active Expired
- 1972-04-04 GB GB1527772A patent/GB1343563A/en not_active Expired
- 1972-04-11 DE DE19722217270 patent/DE2217270A1/en active Pending
Cited By (1)
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 |