Optical sensor built-in circuit operating method for non=contact controlled toilet flush

摘要

The method involves using a circuit device (1) connected to at least one optical sensor (2) for a non-contact controlled toilet flush with an electrically controllable valve (5) for switching water on and off. The sensor has a light transmitter (6) and at least one light detector (7). The transmitter (6) is excited time-wise to generate light pulses. During a time interval the light detector is used to measure the light intensity of the surrounding light in the area to be monitored by the sensor. In a second time interval directly after the first one a light pulse is generated and the light intensity is measured again with the detector. The circuit arrangement only generates a switch signal to actuate the valve when the two measured light intensities differ by a fixed amount.