| 摘要 |
<p>PURPOSE:To achieve high-precision and high-fidelity reproduction without spoiling the characteristics of PCM by installing a coil assembly in a magnetic gap, and powering up a corresponding number of coils in a specified direction by operating switching elements on the basis of a PCM signal. CONSTITUTION:In the magnetic gap G of a magnetic circuit, a coil assembly 5 provided to a bobbin 4 is installed, and the bobbin 4 has many unit integrated elements each consisting of a unit coil 5' and transistors (TR) Q1 and Q4. Those TRs Q1-Q4 operate as switching elements; when a signal appears on a signal line 21a, the TRs Q1 and Q3 turn on and when on a signal line 21b, the TRs Q2 and Q4 turn on. Therefore, the feeding direction of the coil 5' is determined by the signals on the signal lines 21a and 21b. A microporcessor 9 decodes a PCM signal to generate a signal to be applied to the switching elements of the unit elements whose number corresponds to the signal, thereby powering up the coil 5' in a direction which correspond to the polarity. Therefore, the coil 5' operates in the gap G to radiate a sound from a diaphragm 6.</p> |
