LIGHT RESPONSIVE SENSOR SYSTEM

摘要

Relative movement between a barrier positioned with relation to light sources and light sensors produces a signal at the light sensors related to the barrier movement. Two light sources are alternately energized from a regulated voltage controlled current source to provide two sources of light of equal intensity with system perturbations minimized. Two light sensors positioned from the light sources respond to light from both of the alternately energized sources. A signal from a first of the light sensors connects to a voltage follower amplifier that provides a system output signal that varies with and is related to barrier movement. The second light sensor provides a signal to a regulator circuit that controls the current source to the light sources. This signal from the second light sensor is compared with a signal from a reference source to provide light source regulation. As an alternate embodiment, signals from both light sensors are coupled to voltage follower amplifiers each having an output signal related to the barrier movement. These two output signals are summed for a system output signal.