Photo-electric circuit detecting changes of useful light component - has control circuit with time constant stabilising changes of transducer voltage arising from LF interference and constant light

摘要

A photo-electric arrangement produces an electrical output signal corresp. to changes of intensity of the useful light component of a light signal. The latter contains a relatively large interference light component but of lower frequency than the useful component. Such a light signal is produced in certain plasma-physical experiments in which particles of frozen hydrogen are shot past a light source within a light barrier by means of a high powered, focussed laser beam. A photo-electric transducer (10) receives a rest state-working voltage. An associated circuit has a working resistor (R1) coupled to the transducer. This circuit contains an amplifying stage and delivers a signal free from the lower frequency components of the signal produced by the transducer. The circuit includes a control circuit (A1, A2, R4 to R9, C1) to regulate the working voltage of the transducer.