Low cost motor design for rare-earth-magnet loudspeakers

Abstract

A loudspeaker magnetic motor utilizes a voice coil with two or more wire coils that are connected in parallel and that are layered on top of one another. The motor utilizes, as a magnetic field source, a permanent magnet and, more particularly, a permanent magnet that includes a rare earth metal such as a neodymium boron iron magnet.

1 . A loudspeaker magnetic motor comprising
 a voice coil   the voice coil comprising two or more wire coils,   the wire coils being connected in parallel and being layered on top of one another.   
     
     
         2 . A loudspeaker magnetic motor according to  claim 1 , wherein at least one of the coils comprises a conductor having a round cross-section. 
     
     
         3 . A loudspeaker magnetic motor according to  claim 2 , wherein the coils comprise wires having round cross-sections. 
     
     
         4 . A loudspeaker magnetic motor according to  claim 2 , in which
 a first wire coil is disposed about a support, and   a second wire coil is disposed about the first coil.   
     
     
         5 . A loudspeaker magnetic motor according to  claim 1 , comprising a magnetic field source. 
     
     
         7 . A loudspeaker magnetic motor according to  claim 5 , wherein the magnetic field source is a permanent magnet. 
     
     
         8 . A loudspeaker magnetic motor according to  claim 7 , wherein the magnetic field source comprises a rare earth metal. 
     
     
         9 . A loudspeaker magnetic motor according to  claim 8 , wherein the magnetic field source comprises neodymium. 
     
     
         10 . A loudspeaker magnetic motor according to  claim 9 , wherein the magnetic field source comprises a neodymium boron iron magnet. 
     
     
         11 . A loudspeaker magnetic motor according to  claim 10 , wherein the neodymium boron iron magnet has a cylindrical cross-section. 
     
     
         12 . A loudspeaker comprising
 a voice coil   the voice coil comprising two or more wire coils,   the wire coils being connected in in parallel and being layered on top of one another.   
     
     
         13 . A loudspeaker according to  claim 12 , wherein at least one of the coils comprises a conductor having a round cross-section. 
     
     
         14 . A loudspeaker according to  claim 13 , wherein the coils comprise wires having round cross-sections. 
     
     
         15 . A loudspeaker according to  claim 13 , in which
 a first wire coil is disposed about a support, and   a second wire coil is disposed about the first coil.   
     
     
         16 . A loudspeaker according to  claim 12 , comprising a magnetic field source. 
     
     
         18 . A loudspeaker according to  claim 16 , wherein the magnetic field source is a permanent magnet. 
     
     
         19 . A loudspeaker according to  claim 18 , wherein the magnetic field source comprises a rare earth metal. 
     
     
         20 . A loudspeaker according to  claim 19 , wherein the magnetic field source comprises neodymium. 
     
     
         21 . A loudspeaker according to  claim 20 , wherein the magnetic field source comprises a neodymium boron iron magnet. 
     
     
         22 . A loudspeaker according to  claim 21 , wherein the neodymium boron iron magnet has a cylindrical cross-section.