Schaltungsanordnung zur elektrischen Steuerung eines Kameraverschlusses

摘要

1334808 Photo-electric control of exposure time ASAHI KOGAKU KOGYO K K 19 April 1971 [12 March 1970] 22636/71 Heading G2A An electric shutter control network for a camera includes a photo-conductor CdS and an associated logarithmic compression elements D 1 , D 2 connected through an emitter follower circuit Q 1 to a logarithmic expansion circuit Q 2 , and a variable load resistor RF ASA for the emitter follower circuit adjustable in dependance upon diaphragm setting and/or film sensitivity. A second emitter follower circuit may be connected in cascade to the first and of opposite polarity, the load resistors of the two circuits being adjustable in dependence upon diaphragm value and film sensitivity respectively.