PURPOSE: To eliminate the need of a strong stationary magnet, to miniaturize the titled device and to reduce unfavorable influence to an outside by providing a coil to convert an electroacoustic signal into a magnetic flux and its auxiliary coil and a diaphragm partly using a superconductive material.
CONSTITUTION: The electroacoustic signal is separated into a low frequency part and a high frequency part according to its frequency component, the low frequency part is supplied to a terminal B and the high frequency part is supplied to terminals A, A' respectively, converted into a magnetic flux by coils 4, 5 and 6. Simultaneously, a constant electric current flows to terminals C, C' and D and a constant magnetic flux is generated in auxiliary coils 8, 9 and 10. The magnetic flux generated by the coils 4, 5 and 6 and the coils 8, 9 and 10 generates a magnetic flux in the opposite direction to a superconductive material 7 partly mounted on a diaphragm 1 arranged in the front, and its repulsive force is added to the diaphragm 1. The force moves the diaphragm 1 until it is canceled by a damper device 3, and converted into a sound wave as the result. Thus, since the strong stationary magnet is not necessary, the device can be miniaturized and the unfavorable influence to the outside is reduced.
WADA RYOICHI
HIZUKA SADAO
