Passive sensors and control algorithms for faucets and bathroom flushers

Abstract From the Canadian patent

An optical system includes one or several passive optical detectors sensitive to ambient (room) light for controlling for example, the operation of , automatic faucets (9 9A,10, 10A, 1 OB, 1 OC) or automatic bathroom flushers (100, 100A). The passive optical sensors provide signals to flow controllers including control electronics (250) and flow valves (38 140) and require only , very small amounts of electrical power for sensing users of bathroom facilities, and thus enable battery operation for many years. To control the operation of automatic faucets or automatic bathroom flushers based on ambient light, the controller executes novel algorithms (300 600, 900 or 1300).