| 摘要 |
<p>PURPOSE:To obtain a signal-receiving coil which prevents that a signal is input erroneously by an accidentally generated AC magnetic field. CONSTITUTION:A signal-receiving coil 51 is constituted of a first spiral coil 51 a provided with a prescribed winding direction and of a second spiral coil 51b which is installed near the first spiral coil 51a so as not to be overlapped with each other, which is connected in series with the first spiral coil 51a, whose winding direction is opposite and which generates an inductive electromotive force, in the opposite direction, whose magnitude is nearly the same as that of the first spiral coil 51 when it is subjected to the same AC magnetic field. When a magnetic flux is changed on the whole face of the signal-receiving coil 51, inductive electromotive forces generated in the two spiral coils 51a, 51b are offset.</p> |
