JPH0449070B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION The present invention relates to a pulse generator that can be widely applied to various automatic control devices, measuring instruments, control of power transmission and distribution systems, and other electric circuits.

It is an object of the present invention to provide a means for using the pulsed electromotive force generated based on the present invention as a signal or electric power, or for accurately detecting current, etc. from the point at which the pulse is induced.

"Prior Art" As a magnetically sensitive element for pulse generation that is conveniently applied to the present invention, the basic structure and working principle thereof are shown, for example, in Japanese Patent Publication No. 54-50372 and No. 54-50373. .

Apart from these, as a means of generating pulses using magnetic wires, for example, US Pat.
“Self-Nucleating” shown in No. 3820090
"Magnetic Wire" (self-nucleating magnetic wire), or the pulse generator described in Patent Publication No. 13705 of 1972. This magnetic wire has an outer shell with a relatively high coercive force on its outer periphery. The structure is such that it covers the wire core portion, which has a relatively low coercive force.

Then, in the process of removing the external magnetic field that magnetized the entire wire in one direction, only the magnetization direction of the wire core is reversed in the direction of forming a return path of the magnetic lines of force in the outer shell, that is, a closed magnetic path. Although attempts have been made to induce pulses based on changes in magnetic flux during this reversal, they have the disadvantage that the output is generally small and it is difficult to accurately control the timing of pulse generation.

"Summary of the Invention" The asymmetric excitation type pulse generator of the present invention has a uniaxial magnetic anisotropy, and has a portion where the magnetization direction does not change even when an external magnetic field is applied, and an adjacent portion where the magnetization direction changes when an external magnetic field is applied. A magnetically sensitive element made of a composite magnetic material having a portion that can be magnetized in the magnetization direction is used. The device is characterized by comprising a permanent magnet disposed near the magnetically sensitive element, an output coil for inducing electromotive force, and a magnetic field generation source that sequentially excites the magnetically sensitive element from the outside.

In this case, the magnetic field generation source that sequentially excites the magnetic sensing elements from the outside is constructed using magnets that are spaced close to each other or an excitation coil that conducts current.

"Structure and operation of the invention" First, an overview of the magnetically sensitive element applied to the present invention will be given, and then the structure and operation principle of the present invention will be explained.

The magnetic sensing element is, for example, a linear ferromagnetic material that has uniaxial magnetic anisotropy in the line axis direction, has a portion with a relatively large coercive force near the wire core, and a portion with a relatively small coercive force on the outer periphery. It has been processed to have parts. The core portion is a portion whose magnetization direction cannot be changed by an external magnetic field of a predetermined strength, and the outer peripheral portion is a portion whose magnetization direction can be changed in accordance with the direction of the magnetic field. Moreover, when the magnetization direction of the outer peripheral portion is reversed and directed in the same direction as the core portion, it has the property of being able to dislocate extremely rapidly.

Such a magnetic sensing element is operated by applying so-called asymmetrical excitation, in which magnetic fields of different polarities and magnitudes are applied according to the following procedure.

That is, first, the entire magnetic sensing element is magnetized in the positive direction (for example, rightward with respect to the line axis). For example, as shown in FIG. 1, a strong first magnetic field H 1 is generated by passing an alternating current I ₁ through a diode 3 through an excitation coil 2 wound so as to cover the entire magnetically sensitive element ₁ . By applying , the whole is magnetized in the positive direction (for example, rightward with respect to the line axis). Then, turn off the current _I1 .

Next, a relatively small negative -I ₂ is applied to the excitation coil 4 and a weak second magnetic field H ₂ in the opposite direction to H ₁ is applied to reverse only the magnetization direction of the outer periphery to the negative direction (to the left). I'll let it happen.

In this state, a third magnetic field H ₃ due to energization of +I ₂ having a magnitude equal to or greater than −I ₂ is applied again in the same direction as H ₁ (to the right). At this time
In response to the application of H ₃ , the magnetization direction of the outer peripheral portion of the magnetically sensitive element 1 is reversed, and a magnetic flux change occurs accordingly.
Therefore, a pulse electromotive force V _s is generated in the output coil 5 arranged so as to be interlinked with this changing magnetic flux.

In particular, the pulsed power induced by the action of H ₃ is large and steep. Such a unique phenomenon is caused, for example, by the application of the third magnetic field H ₃ triggering the outer circumference, which was currently magnetized in the negative direction (for example, to the left), to reverse direction to the same direction as the core. At this time, an orienting force in the same direction based on the magnetic exchange interaction caused by the orienting magnetism in the positive direction of the core part acts on the outer peripheral part, and this adds an especially rapid reversal force, causing the wire to move in the positive direction more quickly and gradually. (to the right).

Therefore, in response to the magnetic flux change at this time, a particularly steep and large pulsed power is induced in the output coil.

In this case, the second magnetic field H ₂ in the negative direction is for reversing the magnetization of only the outer peripheral portion of the magnetically sensitive element. Therefore, a predetermined magnitude commensurate with the coercive force is a necessary condition, and if it is too small, even if the next positive direction magnetic field acts with sufficient magnitude,
No evoked pulse is obtained.

Therefore, even if these applied magnetic fields are magnetic fields from magnets or alternating current, positive/negative pulsating magnetic fields, or pulsed magnetic fields, or even if they are ultra-low frequencies where the rate of change in flux linkage is extremely small, Alternatively, even with a combination of these magnetic fields, pulses can be reliably generated as long as the above-mentioned asymmetric excitation is performed.

"Embodiment" The embodiment shown in FIG. 2 is configured so that only the outer circumference of the magnetic sensing element 1 is magnetized in the negative direction (downward) by a magnet 8 that is integrated with the output coil 5 and placed close to it. Then, the action of the second magnetic field is applied.

The magnet 7 acts as a magnetic field generation source of the rotating third magnetic field, thereby canceling out the second magnetic field and applying a sufficiently large positive (upward) magnetic field to the magnetically sensitive element 1, as described above. This is to perform asymmetric excitation. Therefore, a steep pulse can be generated in the output coil 5.

In this case, it goes without saying that the application of the third magnetic field also acts as the first magnetic field.

Note that the magnet 7 does not necessarily need to be rotated as shown in the figure, and even if it is simply moved close to and separated from the magnetically sensitive element 1, the same effects can be produced because the magnets are sequentially applied using the asymmetric excitation method described above.

The pulse generator shown in FIG. 3 is an embodiment in which the effects of each of the magnetic fields are provided by a magnet and an excitation coil.

That is, the magnetic sensing element 1 is given the action of the second magnetic field by the magnet 8 disposed close to the output coil 5 so that its outer peripheral portion is magnetized in the negative direction (leftward direction). Then, by applying half-wave current in the positive direction from the AC line 10 through the diode 11 to the excitation coil 9 wound close to or directly around the magnetic sensing element 1, the generated magnetic field is directed to the third point in the positive direction (right direction).
When subjected to the action of a magnetic field, the output coil 5 can be induced to pulse continuously every cycle.

``Effects of the Invention'' As described above, the pulse generator of the present invention has no effects when all magnets are used to apply the magnetic field to the magnetically sensitive element as shown in FIG. Since the pulses can be generated by a power supply, it is useful for constructing synchronous or asynchronous pulse generators and their single or multiple configurations such as non-contact switches and proximity switches.

The electromotive force in this configuration can be directly applied to and responsive to the ignition control of a tachometer, pulse type torque meter, or thyristor, or the drive of a pulse motor.

In particular, it has a unique effect that cannot be obtained with conventional devices of this type, in that it generates pulses exactly the same as those generated at high speeds even when excited at ultra-constant speed rotation.

Furthermore, a device in which the applied magnetic field is applied by energization has the feature that the time point at which the pulse is generated can be accurately and arbitrarily controlled by selecting excitation conditions such as adjusting the number of turns of the excitation coil.

Furthermore, even in the ultra-low frequency range, it has the outstanding effect of being able to generate pulses as reliably as when a commercial frequency current is applied.

Therefore, the stored power can be used in a wide range of electronic and electrical equipment, measurement and control equipment, power transmission system equipment, etc.

For example, it is possible to reliably obtain a pulse signal in the first cycle of asymmetric excitation, and it is also possible to induce one pulse continuously in each cycle, so the control equipment can be operated at any preset timing. It is effective when used for example.

It can also be applied as a digital frequency meter by configuring a maximum/minimum limiter in a pointer-type meter relay, etc., or by counting the number of induced pulses.

When applied to current transformers and transformers in power transmission and distribution systems, it becomes a voltage and current level detector, and can also be applied as a signal source for overcurrent protection relays and current limiters for overload currents and short circuit currents.

Furthermore, it is possible to configure a phase detection device using a plurality of pulse generators of the present invention as a voltage or current detector for each phase of an AC line, or a phase detection device based on a method of timing the generation interval of induced pulses, and furthermore, By appropriately combining it with relays, etc., it can be applied to system monitoring and control.

As described above, the pulse generator using the asymmetric excitation method of the present invention has the potential to be utilized as a component of a large number of new devices.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram regarding the principle of operation of the present invention, and FIGS. 2 and 3 are explanatory diagrams showing each embodiment of the present invention. Code, 1 is a magnetic sensing element, 2 and 4 are exciting coils,
3 and 11 are diodes, 5 is an output coil, 6 is a rotating body, 7 and 8 are magnets, 9 is an exciting coil, and 10 is a line.

Claims (1)

[Scope of Claims] 1. A magnetically sensitive element made of a composite magnetic material having uniaxial magnetic anisotropy, consisting of a portion with a relatively small coercive force and an adjacent portion with a relatively large coercive force; An asymmetrical excitation type pulse generator 2 characterized in that it is constituted by a permanent magnet provided near the magnetically sensitive element, an output coil for inducing electromotive force, and a magnetic field generation source that sequentially excites the magnetically sensitive element from the outside. 2. The asymmetric excitation type pulse generator according to claim 1, wherein magnets that are close to each other and are separated from each other are used as the magnetic field generation source that sequentially excites the magnetically sensitive elements from the outside.