The present invention relates to a low-inductance electromagnetic drive
without driving magnetic flux circuit, which comprises a magnetic pole, a
drive coil, an upper magnetic inductive board, a permanent magnet and a
lower magnetic-inductive board. The magnetic pole is integrated with the
lower magnetic-inductive board, and the permanent magnet is located
between the upper magnetic-inductive board 4 and lower magnetic-inductive
board 6. The drive coil is wrapped around the magnetic pole and is
movable in the axial direction. The electromagnetic drive further
comprises the fastening coil, and the fastening coil is fastened to a
certain proper place of the magnetic flux circuit of the drive coil.
Furthermore, the fastening coil is connected with the drive coil in
opposite phase. The present invention is characterized in that the drive
source applies the excitation to the fastening coil in an equivalent
quantity as the drive coil but in opposite phase, so that the excitation
energy generated by the current flowing through the speaker for the
magnetic flux circuit system is reduced to the minimum, the inductance
quantity of the speaker is decreased to the minimum, and the sound
distortion of the vibration system connected with the drive coil is
decreased.