Automatic exposure control circuit for a camera - has a light measuring device with a photocell receiving light from the camera objective

摘要

The control circuit generates an output signal corresponding to the intensity of the incident light. It comprises further a store for the output signal. A timing capacitor is charged with a current corresponding to the above output signal. A control device is for shutter closure in accordance with the timing capacitor charge, and a current source with a switch between it and the charging device. A switch is in parallel with the timing capacitor. The switching are semiconductors (Q2, Q3) operated by means of a mechanical switch (S5) which blocks the switch (Q3) in parallel with the timing capacitor (C2), and makes a conductor switch (Q2) between th charging device (C1, Q1) and the current source.