Passive sensors and control algorithms for faucets and bathroom flushers

A system for controlling an electronic faucet or bathroom flusher, comprising:

• a body including a water conduit having at least one inlet for receiving water and at least one outlet for providing water;
• a flow valve controlled by an actuator constructed to receive control signals for switching between an open state of said valve and a closed state of said valve;
• said open state permitting water flow from said inlet to said outlet, and said closed state of said valve preventing water flow from said inlet to said outlet;
• a first optical element located at a first optical input port constructed and arranged to define a first field of view having a selected size and orientation that eliminate invalid targets;
• a first light detector optically coupled to said first input port and constructed to detect ambient light arriving to said first detector from said first field of view;
• a second optical element located at a second optical input port constructed and arranged to define a second field of view having a selected size and orientation that eliminate invalid targets;
• a second light detector optically coupled to said second input port and constructed to detect ambient light arriving to said second detector from said second field of view;
• and
• a control circuit for controlling opening and closing of said flow valve, said control circuit being constructed to receive first data from said first light detector corresponding to the detected ambient light from said first field of view, and to receive second data from said second light detector corresponding to the detected ambient light from said second field of view, said control circuit being constructed to determine each said opening and closing of said flow valve based on a background level of said ambient light and a light level caused by a user, said control circuit executing a detection algorithm that processes detection of said increase of ambient light in one of said fields of view and detection of said decrease of ambient light in the other of said fields of view due to the presence of the user to determine each said opening and closing.