Exposure factor switching circuit

摘要

An exposure factor switching circuit in a camera with an exposure control circuit having an emitter follower transistor adapted to apply a voltage through at least one transistor driven by a current flowing in the emitter thereof. A time constant circuit is adapted to control a shutter control magnet with an integration voltage due to a collector current of another transistor to the base of which the output of the emitter follower transistor is applied. A bias current supply circuit is employed having a plurality of transistors one of which is provided with a switch connected to the emitter thereof. The switch is operated to selectively activate the plurality of transistors to vary the emitter current of the emitter follower transistor.