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.

 
Web www.patentalert.com

< Acoustic apparatus and acoustic setting method

> Fingerprint reading method and fingerprint reading system

~ 00454