| 摘要 |
<p>A water faucet (30) is disclosed that is automatically turned on and off in response to the proximity of the user's hand or other object to the faucet. An ultrasonic transducer (24) is located in the faucet near the water outlet (22) and transmits bursts of ultrasonic waves. When a wave reflects off a user's hand and creates an echo signal, the echo is detected by the ultrasonic transducer. Circuitry (26) connected to the ultrasonic transducer determines when an object is within a predetermined distance of the faucet by measuring the time elapsed between the transmission of the , burst and the reception of the echo. Once an object is within this predetermined distance, the circuitry causes a valve (20) ' to open and water is supplied by the faucet.</p> |
