| 摘要 |
PURPOSE:To realize a microphone which is highly resistant to the moisture and highly steady to the electricity by using the piezoelectric magnetic transducer for the sound-electricity conversion transducer. CONSTITUTION:The case is constituted with frame 10 and cover 13, and print substrate 12 and piezoelectric magnetic transducer 13 are stored into the case. At the same time, differential amplifier 14, diode block 15 plus contact pieces 16 and 17 are provided to substrate 12 along with rubber washer 18 attached to frame 10. And output lead 19 is inserted through washer 18 to be connected to amplifier 14. In addition, transducer 13 is held between a pair of ring bodies 20 and 21, and transducer 13 is adhered to piezoelectric magnetic plate 23 on metal plate 22. Thus earth electrode 23 plus a pair of electrodes 25 and 26 are formed. In such constitution, the steady electric signal can be delivered, at the same time ensuring the steady operation to the moisture. |
