| 摘要 |
PURPOSE:To enhance sensitivity with a simple structure and improve the frequency characteristic, by arranging parallel conductor parts of the first and the second spiral parts, which are wound in opposite directions and are connected in series, in the magnetic gap. CONSTITUTION:A magnetic closed circuit is constituted with a magnet, magnetic yoke 15, and pole piece 16a, and a magnetic gap is formed in this closed circuit. Armature 17 is fitted to the back end of cantilever 4, and a pair of support plates 9a and 9b are fitted to this armature 17. Coils 12a and 12b which are constituted with parallel conductor parts, where respective lines are formed densely in parallel, and folding conductor parts, where they are formed thinly, and are constituted with the first and the second spiral parts having winding directions opposite to each other and have parallel conductor parts formed in the middle part between the first and the second spiral parts are caused to adhere to support plates above, and they are inserted into the gap. |
