| 摘要 |
<p>1,219,918. Moving coil transducers. STANDARD TELEPHONES & CABLES Ltd. 8 Aug., 1968, No. 37939/68. Heading H4J. Sound equalization in a moving coil electroacoustic transducer is achieved by one or more holes 202 in a front cover 20 which also serve for the ingress or egress of sound and by a damping grid 17 behind the coil 16 in the form of an annular trough having one or more holes 171 with its inner and outer rims attached to an inner polepiece 11 and yoke 12, 13. The polepiece 11 is larger than, and tops a block cylindrical magnet 10. The diaphragm 14 is preferably formed of plastics material. The magnet 10 is either adhered to the pot 12 or is secured by a press-fit. The transducer may be both the receiver and transmitter of a telephone set. The frequency response may be further adjusted by adjusting the volume between the cover 20 and the ear cap or mouthpiece. Low-frequency response can be cut by making one or more holes in the diaphragm.</p> |
