| 摘要 |
An electro-mechanical transducer has two layers (20) of a polarised piezoelectric polymer coated on each face with a conductive coating (22). The two layers are arranged back to back and secured by a double-sided adhesive tape (24) with their positively charged conductive coatings facing each other. As the protective layers (26) of insulation and a protective sheath (28) are provided. The inner conductive coatings are interconnected by a pin (30) passing through the polymer layers with the outer conductive coating being omitted in the vicinity of the pin. The outer conductive coatings are likewise interconnected by a pin (32), connection to an external screened cable being made through these pins with pin (32) being connected to the outer screen of the cable and pin (30) to the inner signal wire. Because the device is piezo-electric no external power supply is required and interconnection of the two inner conductive coatings enhances the signal generated by the device while the two outer coatings act as an electro-magnetic and electro-static screen to reduce extraneous and unwanted spurious signals which would otherwise affect operation of the device. |
