GB1412370A - Photographic enlargement apparatus - Google Patents

Photographic enlargement apparatus

Info

Publication number
GB1412370A
GB1412370A GB6007373A GB6007373A GB1412370A GB 1412370 A GB1412370 A GB 1412370A GB 6007373 A GB6007373 A GB 6007373A GB 6007373 A GB6007373 A GB 6007373A GB 1412370 A GB1412370 A GB 1412370A
Authority
GB
United Kingdom
Prior art keywords
lamp
exposure
switch
thyristor
capacitor
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
GB6007373A
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 GB1412370A publication Critical patent/GB1412370A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B27/00—Photographic printing apparatus
    • G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Light Sources And Details Of Projection-Printing Devices (AREA)
  • Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)
  • Control Of Exposure In Printing And Copying (AREA)

Abstract

1412370 Exposure control FRANKE & HEIDECKE GmbH [trading as ROLLEI-WERKE FRANKE & HEIDECKE] 28 Dec 1973 [14 Feb 1973] 60073/73 Heading G2A A photographic enlarger has an A.C. powered illumination lamp 3 controlled through a lamp power switch 5 by an exposure time-controlling direct current circuit comprising a relay 6 for operating switch 5, a thyristor 7 and a switch 8 which, when closed after lighting of the lamp and set up of the enlarger for an exposure, causes a firing voltage to be applied to the ignition section of the thyristor and the lamp to be extinguished (with discharge of capacitor 11 and charging of capacitor 14). Lamp 3 is then lit for a timed exposure by closing a switch 13 (with discharge of capacitor 14). Capacitors 22 and 23 then charge up for a time dependent on resistors 18, 20 and 21, after which thyristor 7 fires and lamp 3 is extinguished.
GB6007373A 1973-02-14 1973-12-28 Photographic enlargement apparatus Expired GB1412370A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19732307200 DE2307200B2 (en) 1973-02-14 1973-02-14 PHOTOGRAPHIC ENLARGER

Publications (1)

Publication Number Publication Date
GB1412370A true GB1412370A (en) 1975-11-05

Family

ID=5871870

Family Applications (1)

Application Number Title Priority Date Filing Date
GB6007373A Expired GB1412370A (en) 1973-02-14 1973-12-28 Photographic enlargement apparatus

Country Status (6)

Country Link
US (1) US3895257A (en)
JP (1) JPS49114925A (en)
DE (1) DE2307200B2 (en)
FR (1) FR2218029A5 (en)
GB (1) GB1412370A (en)
IT (1) IT999832B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3403736A1 (en) 2017-05-17 2018-11-21 Primetals Technologies Austria GmbH Guidance of metallic strips in a strip processing system

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3571612A (en) * 1967-12-20 1971-03-23 Ricoh Kk Safety device for an exposure lamp in a reproduction apparatus
US3555390A (en) * 1968-10-07 1971-01-12 Sylvania Electric Prod Switching circuit for motor control in slide scanning systems
US3737734A (en) * 1968-10-25 1973-06-05 Minolta Camera Kk Copying machine
US3742295A (en) * 1970-03-30 1973-06-26 Minolta Camera Kk Lighting system in copying apparatus
US3611049A (en) * 1970-06-29 1971-10-05 Dick Co Ab Automatic power control circuit
DE2043010C3 (en) * 1970-08-29 1979-08-23 Siemens Ag, 1000 Berlin U. 8000 Muenchen Drop-out delayed timing relay
US3697821A (en) * 1971-07-30 1972-10-10 Hunt Electronics Co Light dimming system having multiple control units
US3808456A (en) * 1971-09-27 1974-04-30 Switchpack Systems Remote control switching system

Also Published As

Publication number Publication date
DE2307200B2 (en) 1976-08-05
DE2307200A1 (en) 1974-08-22
JPS49114925A (en) 1974-11-01
US3895257A (en) 1975-07-15
FR2218029A5 (en) 1974-09-06
IT999832B (en) 1976-03-10

Similar Documents

Publication Publication Date Title
ES466449A1 (en) Electronic starter for igniting a discharge lamp
GB1412370A (en) Photographic enlargement apparatus
ES356518A1 (en) Circuit arrangement for igniting and supplying a gas and/or vapour-discharge lamp
GB1328553A (en) Electronic flash tube
JPS52147428A (en) Control device for flash discharge lamp
GB1501213A (en) Pulsed metal or metal halide lamps for photocopying applications
GB1303110A (en)
GB1299523A (en) Electric system for operating a gas discharge lamp
JPS5348727A (en) Discharge flash device
JPS5242670A (en) Discharge lamp lighting device of phase control type
GB1251701A (en)
JPS52118975A (en) Lighting device for discharge lamp
JPS521982A (en) Lighting device of a discharge lamp
JPS5378685A (en) Control circuit of discharge lamp lighting device
JPS5249679A (en) Electronic flash unit
JPS5312177A (en) Device for starting discharge lamp
JPS54153068A (en) Lamp lighting circuit of electronic wristwatches
JPS53107172A (en) Discharge lamp lighting device
JPS5256776A (en) Device for igniting discharge lamp
GB1211706A (en) Discharge-lamp starting circuit
JPS5211675A (en) Discharge lamp lighting device
GB1329852A (en) Control of vapour discharge lamps
JPS51148272A (en) Discharge lamp lighting device
JPS5369480A (en) Control circuit of discharge lamp lighting device
JPS543385A (en) Device for lighting on discharge lamp

Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee