Electrical power generation by coupled magnets

#1. Field of the Invention

#This invention relates to electrical power generation by moving magnets.

#2. Description of the Related Art

#FIG. 1 is a plan view of a conventional permanent magnet, illustrating its associated magnetic field line;

#FIGS. 2a, 2b, 2c, 2d and 2e are simplified sectional views showing sequential stages in the movement of a magnet through a coil;

#FIG. 3 is a graph illustrating a voltage output produced from the magnet movement of FIGS. 2a-2e;

#A conventional permanent magnet 2 is illustrated in FIG. 1, with north and south poles designated N and S, respectively. The magnet generates a magnetic field that has a maximum density external to the magnet in the areas 4 and 6 adjacent to the poles, as indicated by the magnetic field lines 8 shown in the drawing. For purposes of electrical generation with a linear generator having a magnet movement parallel to the magnet axis, the operative portion of the magnetic field is the component parallel to the magnet's axis.

#FIGS. 2a-2e together with FIG. 3 illustrate the generation of an electrical signal in a coil 10 through which a magnet 12 passes. As the magnet passes through it induces a voltage in the coil to generate a current when the coil circuit is closed. The induced voltage is proportional to the rate of change of the total magnetic flux in the axial direction through the coil; the total axial magnetic flux can be calculated by integrating the product of the directional magnetic field and the area encompassed by the coil over the length of the coil.

#In FIG. 2a the magnet 12 is shown outside and to the left of the coil 10, at a position where the right-most portion of its magnetic field just begins to enter the coil. This corresponds to area 14 in FIG. 3, which traces the voltage in the coil as the magnet passes through it. At this point little or no voltage is generated.