GB2017431A - Electronic flash device - Google Patents

Electronic flash device

Info

Publication number
GB2017431A
GB2017431A GB7907602A GB7907602A GB2017431A GB 2017431 A GB2017431 A GB 2017431A GB 7907602 A GB7907602 A GB 7907602A GB 7907602 A GB7907602 A GB 7907602A GB 2017431 A GB2017431 A GB 2017431A
Authority
GB
United Kingdom
Prior art keywords
resistance
capacitor
limb
charging
flash
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.)
Granted
Application number
GB7907602A
Other versions
GB2017431B (en
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.)
Balda Werke Photographische Gerate und Kunststof GmbH and Co KG
Original Assignee
Balda Werke Photographische Gerate und Kunststof 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 Balda Werke Photographische Gerate und Kunststof GmbH and Co KG filed Critical Balda Werke Photographische Gerate und Kunststof GmbH and Co KG
Priority to GB7908272A priority Critical patent/GB2017444B/en
Priority to DE19792910071 priority patent/DE2910071A1/en
Priority to FR7906507A priority patent/FR2420245B1/en
Priority to US06/020,587 priority patent/US4260968A/en
Priority to SE7902284A priority patent/SE7902284L/en
Priority to CA000323530A priority patent/CA1137181A/en
Priority to NL7902034A priority patent/NL7902034A/en
Priority to JP2983079A priority patent/JPS54129951A/en
Publication of GB2017431A publication Critical patent/GB2017431A/en
Application granted granted Critical
Publication of GB2017431B publication Critical patent/GB2017431B/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

  • Stroboscope Apparatuses (AREA)

Abstract

In an electronic flash device, in or for a camera, unnecessarily rapid battery deterioration is avoided, and adequate charge maintained for a flash of a prescribed intensity, by providing means 10 for indicating a required state of charge of a flash- initiation capacitor 9 in response to the output of a potentiometer having a first limb of fixed resistance 13 and a second limb 14, 11, T3 which has a different resistance during capacitor charging from that after termination of such charging. The difference in resistance may be obtained by bridging part 11 of the resistance of the second limb by means of a switch, conveniently a transistor T3 which conducts only during charging of the capacitor 9 from supply 8. Conveniently the supply 8 to the capacitor 9 is controlled by a push-button on-off switch S1, S2 which is held closed by an electromagnet 4 at low levels of ambient light, detected by photo- resistance 2, and released by the indicating means 10. The arrangement is such that the device has an artificial hysteresis. <IMAGE>
GB7907602A 1978-03-06 1979-03-05 Electronic flash device Expired GB2017431B (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
GB7908272A GB2017444B (en) 1978-03-14 1979-03-08 Active filter network
FR7906507A FR2420245B1 (en) 1978-03-14 1979-03-14 ACTIVE FILTER CIRCUIT WITHOUT INDUCTORS, AND RESULTING BAND PASS FILTERS
US06/020,587 US4260968A (en) 1978-03-14 1979-03-14 Active filter network utilizing positive impedance converters
SE7902284A SE7902284L (en) 1978-03-14 1979-03-14 ACTIVE FILTER CIRCUIT
DE19792910071 DE2910071A1 (en) 1978-03-14 1979-03-14 BANDPASS FILTER
CA000323530A CA1137181A (en) 1978-03-14 1979-03-14 Active filter networks
NL7902034A NL7902034A (en) 1978-03-14 1979-03-14 ACTIVE FILTER NETWORKS.
JP2983079A JPS54129951A (en) 1978-03-14 1979-03-14 Active filter circuit network

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19782809617 DE2809617A1 (en) 1978-03-06 1978-03-06 ELECTRONIC FLASH DEVICE

Publications (2)

Publication Number Publication Date
GB2017431A true GB2017431A (en) 1979-10-03
GB2017431B GB2017431B (en) 1982-05-26

Family

ID=6033694

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7907602A Expired GB2017431B (en) 1978-03-06 1979-03-05 Electronic flash device

Country Status (4)

Country Link
DE (1) DE2809617A1 (en)
FR (1) FR2419645A1 (en)
GB (1) GB2017431B (en)
IT (1) IT1111129B (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1120018B (en) * 1957-11-02 1961-12-21 Harro Mueller Dipl Ing Flash unit with control circuit
NL161031C (en) * 1968-01-17 1979-12-17 Philips Nv DEVICE FOR IGNITING AND FEEDING A DISCHARGE FLASHLIGHT.
US3586906A (en) * 1968-02-23 1971-06-22 Nippon Kogaku Kk Control circuit for photoflash discharge lamps

Also Published As

Publication number Publication date
IT1111129B (en) 1986-01-13
DE2809617A1 (en) 1979-09-13
FR2419645A1 (en) 1979-10-05
IT7920723A0 (en) 1979-03-02
GB2017431B (en) 1982-05-26

Similar Documents

Publication Publication Date Title
GB1523421A (en) Flash and camera device
JPS5220021A (en) Exposure control device for the camera
JPS5652740A (en) Camera having data imprinting device
JPS5298520A (en) Lens shutter for focal plane shutter camera
GB2017431A (en) Electronic flash device
JPS5370819A (en) System for determining exposure requirements of camera
JPS5348727A (en) Discharge flash device
JPS5317331A (en) Controlling circuit of camera in response to signal from strobo firing device
JPS54141629A (en) Program control system of aperture and shutter priority camera
JPS5447644A (en) Warning display device of cameras
FR2325960A1 (en) Automatic photographic unit for thermographic pictures - has heat sensitive foil as well as camera and illumination control systems
JPS5724924A (en) Preparing device for flashlight photographying in flashing apparatus self-containing camera
JPS57105731A (en) Self-processing camera for endoscope
GB2016221A (en) Electronic flash device
JPS51112336A (en) Flashing device for a close photographing
JPS5411722A (en) Automatic film winding mechanism of cameras
JPS5511239A (en) Aperture control unit in flash photography
JPS5540481A (en) Camera having distance detector
JPS5714828A (en) Electric charging completion display device for camera
JPS5447627A (en) Control circuit for amount of exposure to light of photographing information
JPS55591A (en) Flash lighting device
JPS52414A (en) Camera having seal-opening device of film magazine
JPS52113730A (en) Camera
JPS5546724A (en) Flash camera device
JPS57135936A (en) Power supply circuit for camera

Legal Events

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