JP2517892Y2 - Pulse generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a pulse generator that applies a magnetic field to a ferromagnetic rod and a detection coil to generate a pulse voltage.

[Prior Art] Conventionally, as shown in FIG. 5, as a pulse generator, a ferromagnetic rod 11 having a central part with high coercive force and a peripheral part with low coercive force, which causes a large Barkhausen inversion phenomenon, has been used. The detection coil 12 is wound, the set magnet 13 and the reset magnet 14 are arranged in the vicinity of these ferromagnetic rods 11, and the reset magnets 14 are reciprocally moved in the direction of approaching and separating from the ferromagnetic rods 11. Is known.

As a pulse generator, as shown in FIG.
A detection coil 12 is wound around a ferromagnetic rod 11 having a high coercive force center portion and a low coercive force peripheral portion to generate a large Barkhausen inversion phenomenon, and a set magnet 13 and a magnet are provided in the vicinity of these ferromagnetic rods 11. Arrange the reset magnet 14, and
It is known that the reset magnet 14 is rotated so as to move toward and away from the ferromagnetic rod 11.

In these pulse generators, the magnetic field generated by the action of the set magnet 13 and the reset magnet 14 changes sinusoidally as shown in FIG. A pulse voltage is induced as shown in b).

[Problems to be Solved by the Invention] However, in the conventional pulse generator of this type,
Since the set magnet 13 is usually rod-shaped, the ferromagnetic rod 11
There is a problem that positioning for applying an optimum magnetic field is troublesome and the size becomes large.

An object of the present invention is to easily position a set magnet for applying an optimum magnetic field to a ferromagnetic rod, and
It is to provide a pulse generator suitable for miniaturization.

[Means for Solving the Problems] According to the present invention, a ferromagnetic rod having a high coercive force central portion and a low coercive force peripheral portion that causes a large Barkhausen inversion phenomenon is provided with a detection coil, and In a pulse generator that applies a magnetic field to these ferromagnetic rods and a detection coil to generate a pulse voltage, a bobbin is fitted to the ferromagnetic rods, and a magnetic field in a uniform direction is constantly applied to the ferromagnetic rods. Thus, a pulse generator is obtained in which two set magnets are attached to both ends of the bobbin and the detection coil is wound around the bobbin between the set magnets.

[Embodiment] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 indicates a ferromagnetic rod. The ferromagnetic rod 1 has a center portion having a high coercive force and a peripheral portion having a low coercive force, and causes a large Barkhausen inversion phenomenon. A cylindrical bobbin 2 is fitted to the ferromagnetic rod 1 from the outside. Two cylindrical set magnets 3 are fitted to the both ends of the bobbin 2 from the outside. The set magnets 3 are arranged so that the polarities of the facing magnetic poles are different from each other, and always apply a magnetic field in a uniform direction to the ferromagnetic rod 1. The set magnet 3
The detection coil 4 is wound around the intermediate portion of the bobbin 2 located between the two.

A reset magnet 5 is arranged near the set magnet 3. This reset magnet 5
Are reciprocally moved or rotated in a direction of approaching and separating from the set magnet 3. Reset magnet 5
When A moves periodically, the number of magnetic fluxes passing through the detection coil 4 changes greatly, so that a pulse voltage is generated in the detection coil 4.

The set magnet 3 may have a columnar shape as shown in FIG. 3 or a rectangular parallelepiped shape as shown in FIG.

[Advantages of the Invention] The pulse generator of the present invention facilitates positioning of the set magnet for applying an optimum magnetic field to the ferromagnetic rod, and is suitable for downsizing.

Further, since the coil and the set magnet are attached to the bobbin fitted to the ferromagnetic rod, they are easy to make, and since they are integrated, they are easy to use.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is an exploded perspective view showing the essential parts of the same embodiment, FIG. 3 and FIG.
FIG. 1 is a perspective view showing an essential part of another embodiment of the present invention,
5 and 6 are perspective views showing a conventional pulse generator, respectively, and FIG. 7 (a) is a diagram showing changes in the magnetic field generated by the action of a set magnet and a reset magnet in the conventional pulse generator, and FIG. Figure 7 (b)
FIG. 6 is a diagram showing a change in pulse voltage induced in a detection coil in a conventional pulse generator. 1 ... Ferromagnetic rod, 3 ... Set magnet, 4 ... Detection coil, 5 ... Reset magnet.

Claims (1)

(57) [Scope of utility model registration request] 1. A ferromagnetic rod having a high coercive force central portion and a low coercive force peripheral portion, which produces a large Barkhausen inversion phenomenon, is provided with a detection coil, and these ferromagnetic rod and detection coil are provided. In a pulse generator that applies a magnetic field to generate a pulse voltage, a bobbin is fitted to the ferromagnetic rod, and two set magnets are provided to each of the bobbin so as to constantly apply a magnetic field in a uniform direction to the ferromagnetic rod. A pulse generator mounted on both ends of the bobbin, and the detection coil wound around the bobbin between the set magnets.