| 摘要 |
PURPOSE:To simplify the mechanism of a detection part by allowing a control circuit, composed of a micro computer, etc., to detect the vibration of a vibrating piece stopping or its frequency or amplitude lowering when the vibrating piece comes into contact with a body. CONSTITUTION:Vibrating piece 1 has one terminal fixed and the other extended in contact with a body to be detected, and magnetic material 2 and magnet 3 are fixed to vibrating piece 1. One output of driving coil 4 coupled electromagnetically with magnetic material 2 is connected to an electric power source and the other to the collector of transistor 7 of driving circuit 6. As the body comes into contact with vibrating piece 1, the body stops vibrating piece 1 from vibrating, so that its vibration frequency will fall or become zero. This is detected by control circuit 11 to know the existence of the body. |
