| 摘要 |
A loudspeaker comprises a motor structure which incorporates a magnetic flux control system including a field winding, a controller connected between a voltage source and the field winding and, a polarity reversal switch preferably located across the filed winding. The magnetic flux control system is operative to produce a magnetic flux, which, depending on the level and polarity of electrical current supplied to the field winding, either reinforces or opposes the static magnetic flux produced by the magnet of the motor structure of the loudspeaker, thus altering the motor strenght of the loudspeaker system. |
