Temp. compensation circuit for dark current changes - has control circuit whose inputs are connected to monitoring unit and level control stage

摘要

The t.v. camera circuit has a temp. compensation unit to allow for dark current changes. The sensitive surface consists of semiconductor material, and has a video circuit containing the compensation unit. The voltage level input of a level restoring and limiting stage (4) is connected to the output of a control circuit (2) whose one input is connected to a monitoring unit (1), and the other input to a level control stage (3). The positive terminal of the semiconductor conversion element is connected to a diode, through a resistor to the base terminal of an FET, the drain terminal is also connected to the positive terminal. The source terminal of the FET is connected to earth through a fixed resistor, a diode and a variable resistor.