JP3431480B2 - Pulse signal generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse signal generator, and more particularly to a pulse signal generator capable of detecting the position and moving direction of a detected object.

[0002]

2. Description of the Related Art It is often necessary in various fields such as switches of electric and electronic devices to obtain a pulse signal according to the position and moving direction of a moving object without a power source. However, heretofore, there has been no effective means for generating such a pulse signal. Further, in order to generate such a pulse signal, some kind of power source is usually required, and therefore, for example, a standby power source is required even when the pulse signal is not generated for a long time. However, this standby power source consumes electricity in vain, and the existence of such standby power source poses a risk of causing problems such as electric leakage and explosion.

Further, like a reed switch, for example,
Some mechanical structures are used to generate pulse signals, but when such mechanical structures are used, there is a high risk of chattering, and there is a problem of lack of reliability and safety. Further, when the pulse signal is generated by mechanical contact, the pulse signal may not be generated due to abrasion of the contact portion or accumulation of dust on the contact portion. Furthermore, in general, when generating pulse signals by mechanical contact, such generators often have to be isolated from water and oil, which results in a limited field of use of the device and also However, there is also a drawback that such a device becomes large in size.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the above-mentioned prior art.
An object of the present invention is to provide a pulse signal generator capable of detecting the position and moving direction of an object. Another object of the present invention is to provide a pulse signal generation device that does not chatter while saving power by generating a pulse signal without a power source. A further object of the present invention is to provide a pulse signal generator that can be used in water or oil.

According to one aspect of the present invention, a magnetic element capable of causing a large Barkhausen jump, a detecting means for the magnetic element, and a bias magnetic field for causing the magnetic element to perform a predetermined magnetization. a first magnetic field generating means for applying, magnetic
A second magnetic field generating means for applying a main magnetic field for producing a large Barkhausen jump to the element , wherein the magnetic element and the second magnetic field generating means are arranged in parallel with each other.
They are arranged in rows and move relative to each other while maintaining this parallel relationship.
Move toward and away from each other
The magnetic element and the second magnetic field generating means in phase with each other.
By moving them closer or further away from each other,
Bias magnetism by the first magnetic field generating means in the element
Field and the main magnetic field generated by the second magnetic field generating means.
A pulse is generated in the magnetic element by changing the influence relatively.
Pulse signal for detecting the pulse by the detecting means.
It features a signal generator.

In the above apparatus, the first magnetic field generating means
A step with the magnetic element and the second magnetic field generating means
May be arranged in parallel with each other. Also, in the above device
The magnetic element and the second magnetic field generating means are in phase with each other.
When approaching or moving away from each other,
The first magnetic field generating means are relatively close to each other and
Does not have to move away, and the magnetic element
And the second magnetic field generating means are relatively close to each other
Correspondingly, when moving away from the magnetic element
If the first magnetic field generating means are moved away from each other,
You may approach. Further, in the above device, the magnetic
Element and the second magnetic field generating means are relatively close to each other
The via by the first magnetic field generating means.
Main magnetic field generated by the second magnetic field generating means rather than the magnetic field
Due to the influence of the second magnetic field generating means.
A large Barkhausen jump occurs in the magnetic element.
1 position, the magnetic element and the second magnetic field generating means
The second magnetic field is generated by moving the second magnetic field away from each other.
The first magnetic field generating means rather than the main magnetic field generated by the generating means.
The second position where the bias magnetic field due to
To generate the pulse, and the pulse to the detecting means.
You may make it detect more. In addition, with the first position
No pulse is generated at any position other than the second position. Well
Also, the pulses generated at the first position and the second position
May be different in their orientation or size
Yes.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Before describing the embodiments of the present invention, a "magnetic element capable of causing a large Barkhausen jump" (hereinafter sometimes simply referred to as a magnetic element) used in the present invention will be briefly described. deep. First, as an example of a commonly known wire-shaped composite magnetic element,
Its structure and behavior will be described. A thin wire made by drawing a ferromagnetic material has unique magnetic properties together with its alloy composition. When a twisting stress is applied to this ferromagnetic wire, the wire is twisted more in the vicinity of the outer peripheral portion and less in the central portion, so that the outer peripheral portion and the central portion have different magnetic characteristics. When processing is performed to leave this state, a ferromagnetic magnetic wire having different magnetic properties at the outer peripheral portion and the central portion is formed. The magnetic characteristic of the outer peripheral portion changes its magnetization direction by a relatively small magnetic field. On the other hand, the central portion changes its magnetization direction by a magnetic field larger than that of the outer peripheral portion. That is, in one magnetic wire, a composite magnetic body having two kinds of different magnetic characteristics, that is, an outer peripheral portion having a magnetic characteristic that is relatively easily magnetized and a central portion that is not easily magnetized is formed. This composite magnetic wire is uniaxially anisotropic. Here, the outer peripheral portion is referred to as a soft layer, the central portion is referred to as a hard layer, and such a composite magnetic wire is referred to as a wire-shaped composite magnetic element.

The hard layer and the soft layer of the composite magnetic wire are initially in uncertain magnetization directions, and are in different magnetization states. When an external magnetic field sufficient to reverse the magnetization direction of the hard layer is applied in the longitudinal direction of this composite magnetic wire, that is, parallel to the axial direction, the soft layer is naturally magnetized also in the hard layer, and the same magnetization direction is obtained. Sour. Then, an external magnetic field is applied in the opposite direction to the one that can magnetize only the soft layer. As a result, the soft state and the hard layer of the composite magnetic wire are magnetized in opposite directions. Because of the uniaxial anisotropy, even if the external magnetic field is removed in this state, the magnetization direction of the soft layer is suppressed by the magnetization of the hard layer and the magnetization state is stable. The external magnetic field at this time is called a set magnetic field. Next, an external magnetic field in the direction opposite to the set magnetic field is applied to increase this magnetic field. When the strength of the external magnetic field exceeds a certain critical strength, the magnetization direction of the soft layer is rapidly reversed. This magnetic field is called the critical magnetic field. In the reversal phenomenon at this time, the domain wall of the soft layer moves like an avalanche and a reaction occurs. As a result, the magnetization directions of the soft layer and the hard layer are the same and the initial state is restored. The external magnetic field has a magnetic field larger than the critical magnetic field. This magnetic field is called the reset magnetic field. The phenomenon in which the domain wall moves like this avalanche is called the large Barkhausen jump. The velocity of the domain wall (change in magnetic flux density) depends only on this large Barkhausen jump and is independent of the external magnetic field.

Although the "magnetic element capable of causing a large Barkhausen jump" has been described by taking a wire-shaped magnetic element as an example, the present invention is not limited to such a wire-shaped composite magnetic element. , Other various magnetic elements that exhibit similar behavior can be used. Further, the composite magnetic element described above has a hard layer and a soft layer, but a magnetic element capable of causing a large Barkhausen jump has such a composite layer of a hard layer and a soft layer. It is possible to use a magnetic element that does not exist. For example, by using a thin film forming technique such as disclosed in JP-A 4-2189 05 JP, to form a thin film of magnetic material which can also be used as a thin-film magnetic element. Further, this magnetic element may have a thick film shape or a plate shape. Therefore, the “magnetic element capable of causing the large Barkhausen jump” as used herein includes all of various magnetic elements that exhibit the above-described behavior. In addition, when it is made into a plate shape or a film shape, it may be a flat coil.

Next, with reference to FIG. 1, an example of use of the pulse signal generator according to an embodiment of the present invention will be described. Figure 1
Shows schematically an example of use of the pulse signal generator according to the present invention when the pulse signal generator according to this embodiment is installed in a door portion of a refrigerator, for example. This pulse signal generator is arranged along the vicinity of the magnetic element 10 and a detection coil 20 wound around the rod-shaped magnetic element 10 which is a wire-shaped element. A bias magnet 30 as a magnetic field generating means for generating a magnetic field (bias magnetic field) capable of magnetizing the soft layer in the opposite direction with respect to the hard layer, and the hard layer of the magnetic element 10 when arranged near the magnetic element 10. On the other hand, the main magnet 40 is provided as a magnetic field generating means for generating a magnetic field (main magnetic field) capable of magnetizing the soft layer in the same direction. Incidentally, the influence of the bias magnetic field from the bias magnet 30 and the main magnetic field from the main magnet 40 naturally appears even in a place apart from each magnet to some extent. In other words, each magnet has a predetermined operation area. Note that the positional relationship of the above-described constituent members is not limited to that shown in the drawing, and the order may be changed.

Among these members, the magnetic element 10, the detection coil 20, and the bias magnet 30 are fixed to the main body side of the refrigerator 1, for example, the frame of the main body 70, and the main magnet 40 is the door of the refrigerator 1. It is fixed to a side, for example, a corresponding position on the edge of the door 60. As a result, by opening and closing the door 60, these members can move relative to each other, either toward or away from each other. That is, when closing the door 60 of the refrigerator (when moving in the direction of arrow A in the figure), the magnetic element 10, the detection coil 20, the bias magnet 30, and the main magnet 40 approach each other, while
When the refrigerator door 60 is opened (moved in the direction of arrow B in the figure), they move away from each other. However, as described above, the magnetic element 10, the detection coil 20, and the bias magnet 30 are not necessarily provided, and the main magnet 40 is provided on the main body side.
It is not necessary to fix it on the door side, but on the contrary, the main magnet 40
The magnetic element 10, the detection coil 20, and the bias magnet 30 may be fixed to the main body side to the door side. What is important here is that the magnetic element 10, the detection coil 20, the bias magnet 30, and the main magnet 40 can move relative to each other.

The bias magnet 30 and the main magnet 40 are
Both are formed as rod-shaped permanent magnets, and are arranged in parallel to the magnetic elements 10, respectively. This state is maintained even when the door 60 is opened and closed. Each magnet 3
Nos. 0 and 40 are respectively magnetized in the axial direction, and their magnetic poles (N pole, S pole) appear at both ends thereof. In FIG. 1, in particular, the bias magnet 30 is arranged so that the N pole faces upward and the S pole faces downward, and the main magnet 40 has the S pole facing upward and the N pole faces downward. The bias magnet 30 and the main magnet 40 need to be opposite to each other. Therefore, contrary to the above, the bias magnet 30 has the N pole on the lower side and the S pole on the upper side. With respect to, it is also possible to arrange so that the S pole faces downward and the N pole faces upward.

Next, the operation of the pulse signal generator when the door 60 is opened and closed will be described with reference to FIGS. Here, A ₁ , A ₂ , B, and C in FIG. 1 respectively indicate the positions of the main magnets 40 fixed to the door 60, and FIG. It shows the pulse voltage that can be generated when the positions A ₁ , A ₂ , B and C are reached (and not at positions A ₂ , B, as described below). First, when the door 60 is closed, more specifically, the main magnet 40 is moved to A _{1 in} FIG.
The case of moving from the left side position in the direction of arrow a will be described. The door 60 is moving in the direction of arrow a,
When it is still far from the main body 70, the main magnet 4
0 is also far from the magnetic element 10 (for example,
In the position C), the magnetic field applied from the main magnet 40 to the magnetic element 10 is weak, and the magnetic element 10 is hardly affected by the main magnet 40. Therefore, in this case, the detection coil 20 does not generate a pulse signal. However,
Even in this case, since the magnetic element 10 is affected by the magnetic field of the bias magnet 30 arranged in the vicinity thereof, only its own soft layer is magnetized in the opposite direction to the hard layer.

As the door 60 approaches the body 70,
The main magnet 40 can also approach the magnetic element 10. When the main magnet 40 approaches the magnetic element 10 to some extent,
The influence of the magnetic field generated by the main magnet 40 appears in the magnetic element 10. The position of the main magnet 40 at this time is indicated by A ₁ . To be precise, even at this time, the magnetic element 10
Is affected by the magnetic field from the bias magnet 30, but at least when the main magnet 40 reaches the position A ₁ in FIG. 1, the magnetic field exerted by the main magnet 40 on the magnetic element 10 is the bias magnet. It is assumed that the magnetic field 30 is more dominant than the magnetic field exerted on the magnetic element 10 and the magnetic field of the main magnet 40 influences the magnetic element 10. Due to the influence of the magnetic field of the main magnet 40, the magnetic field applied to the magnetic element 10 is reversed and a magnetic field in the same direction as the hard layer is applied. Therefore, the soft layer of the magnetic element 10 is inverted in the same direction as the hard layer, and as a result, a large Barkhausen jump occurs, and the soft layer and the hard layer can be magnetized in the same direction. This is because the magnetic field of the soft layer is changing at a very high speed, so that a pulse voltage is generated in the detection coil 20 by the electromagnetic induction effect. As described above, by the action of the main magnet 40, the change in the movement of the door 60 is converted into the change in the magnetization state of the magnetic element 10 by the main magnet 40. A change in magnetization in the magnetic element 10 is detected as a pulse voltage by the detection coil 20 wound around the magnetic element 10. The pulse voltage detected at this time is shown in FIG.
It shows with.

After the pulse voltage a is detected, the door 60
No matter how close the body 70 is to the main body 70, “the magnetic field exerted by the main magnet 40 on the magnetic element 10 is superior to the magnetic element 10 by the bias magnet 30”. Since the state is maintained, the detection coil 20 does not generate a pulse voltage. 1B is a door 60
The position of the main magnet 40 when the is completely closed is shown. At this time as well, since the above-described state is similarly maintained, the magnetization of the magnetic element 10 hardly changes. Therefore, as shown in FIG. 2, the detection coil 20 does not generate a pulse voltage. Next, when you open the door,
A case where the main magnet 40 moves in the direction of arrow B from the position shown in B of FIG. 1 will be described. When the door 60 is moving in the direction of arrow B, but the door 60 is still close to the main body 70, the state described above, that is,
“The magnetic field that the main magnet 40 exerts on the magnetic element 10 is
Rather than the magnetic field that the bias magnet 30 exerts on the magnetic element 10,
Since the “dominant over magnetic element 10” state is maintained, the detection coil 20 does not generate a pulse voltage.
This state is the same when the main magnet 40 reaches the position A ₂ in FIG. Therefore, as shown in FIG. 2, the detection coil 20 does not generate a pulse voltage even at the position A ₂ .

Further, when the door 60 moves away from the main body 70, the main magnet 40 moves away from the magnetic element 10 accordingly, and when the main magnet 40 moves away to some extent, the magnetic field of the bias magnet 30 influences the magnetic element 10.
Appear in. The position of the main magnet 40 at this time is indicated by C. To be precise, even at this time, the magnetic element 10
Is affected by the magnetic field of the main magnet 40,
At least when the main magnet 40 reaches the position C in FIG. 1, the magnetic field exerted by the bias magnet 30 on the magnetic element 10 is larger than that exerted on the magnetic element 10 by the main magnet 40. It is assumed that the magnetic field is influenced by the bias magnet 30 and the influence of the magnetic field of the bias magnet 30 appears on the magnetic element 10. Due to the influence of the magnetic field from the bias magnet 30, the magnetic field applied to the magnetic element 10 is reversed, a magnetic field in the opposite direction to the hard layer is applied, and the soft layer can be magnetized in the opposite direction to the hard layer. A change in the magnetization of the magnetic element 10 due to the bias magnet 30 can be detected as a pulse voltage by the detection coil 20 wound around the magnetic element 10. The pulse voltage detected at this time is shown by b in FIG.

As described above, according to the pulse signal generator of the present invention, two kinds of pulse voltages a and b having different magnitudes and different directions are used when the door is opened and when the door is closed.
Is generated, the position and moving direction of the door can be detected by identifying these pulse voltages. That is, when the pulse voltage a is detected, it is found that the door 60 is at the position A ₁ and is moving in the direction of closing the door (direction of arrow a), while
When the pulse voltage b is detected, it can be seen that the door 60 is at the position C and is moving in the direction of opening the door (direction of arrow B). Further, the door 60 is located at the position A.
_Since the pulse voltage is not generated immediately after reaching ₁ to the position B and immediately before reaching the position C from the position B through the position A ₂ , this section is used as a dead zone. be able to. That is, the presence of such a section allows the movement of the door to be accurately captured without causing chattering, for example, even when the door slightly moves due to opening and closing of the door. The size of the dead zone can be freely set by appropriately adjusting the strength and arrangement of each magnet, and thus the configuration of the present invention can be appropriately used according to various situations. .

Next, a second embodiment of the present invention will be described with reference to FIG. Unlike FIG. 1, this figure schematically shows only the configuration of the pulse signal generator according to the second embodiment of the present invention. In this embodiment, the bias magnet 30A and the main magnet 40A are fixed, and conversely, the magnetic element 10A and the detection coil 20A move in the directions A to B with respect to these magnets 30A and 40A. Is set to get. Here, the magnetic element 10
A and the detection coil 20A are arranged in parallel with the bias magnet 30A and the main magnet 40A, respectively, and this state is maintained even when the magnetic element 10A and the detection coil 20A move. Next, further referring to FIG. 4, the operation of the pulse signal generator when the magnetic element 10A and the detection coil 20A are moved will be described.

Here, A'and B'in FIG. 4 respectively indicate the positions of the magnetic element 10A and the detection coil 20A in FIG. 3, and a'and b'in FIG. 4 indicate the magnetic element 10A. And the pulse voltage generated when the detection coil 20A reaches each of these positions A ′ and B ′. First,
The case where the magnetic element 10A and the detection coil 20A approach the main magnet 40A from the intermediate position between the bias magnet 30A and the main magnet 40A, that is, the case where the magnetic element 10A and the detection coil 20A move in the direction of arrow A in FIG. 3, will be described. As the magnetic element 10A and the detection coil 20A approach the main magnet 40A, the influence of the magnetic field from the main magnet 40A exerted on the magnetic element 10A becomes stronger, and conversely, the influence of the magnetic field from the bias magnet 30A exerted on the magnetic element 10A. Weakens. Therefore, when the magnetic element 10A and the detection coil 20A approach the main magnet 40A to some extent, the magnetic element 10 may be affected by the magnetic field of the main magnet 40A. The positions of the magnetic element 10A and the detection coil 20A at this time are indicated by A'in FIG. To be precise, even at this time, the magnetic element 10
A and the detection coil 20A are affected by the magnetic field from the bias magnet 30A, but at least the magnetic element 10
When A and the detection coil 20A reach the position of A ′ in FIG. 3, the magnetic field exerted by the main magnet 40A on the magnetic element 10 is applied to the magnetic element 10A more than the magnetic field exerted on the magnetic element 10 by the bias magnet 30A. On the other hand, it is assumed that the magnetic field is dominant and the influence of the magnetic field of the main magnet 40A appears on the magnetic element 10A. When the magnetic element 10A and the detection coil 20A reach the position A'in FIG. 3, the magnetic field applied to the magnetic element 10A is reversed by the influence of the magnetic field from the main magnet 40A, and a magnetic field in the same direction as the hard layer is applied. . Therefore, the soft layer of the magnetic element 10A is inverted in the same direction as the hard layer, and as a result, a large Barkhausen jump occurs, and the soft layer and the hard layer can be magnetized in the same direction. This is because the magnetic field of the soft layer is changing at a very high speed, so a pulse voltage is generated in the detection coil 20A by the electromagnetic induction effect. In this way, the movement of the magnetic element 10A and the detection coil 20A is changed by the action of the main magnet 40A.
Is converted into a change in the magnetization state with respect to the magnetic element 10A. The change in the magnetization in the magnetic element 10A can be detected as a pulse voltage by the detection coil 20A wound around the magnetic element 10A. The pulse voltage detected at this time is shown by a'in FIG.

After the pulse voltage a'is detected, no matter how close the magnetic element 10A and the detection coil 20A are to the main magnet 40A, the above-mentioned state, that is, "the main magnet 40A affects the magnetic element 10A. The state in which the magnetic field is superior to the magnetic element 10A over the magnetic field exerted by the bias magnet 30A on the magnetic element 10A is maintained ”, so that the detection coil 20A does not generate a pulse voltage. This state is maintained until the magnetic element 10A and the detection coil 20A further move away from the main magnet 40A and reach immediately before the bias magnet 30A. Next, the case where the magnetic element 10A and the detection coil 20A approach the bias magnet 30A from the intermediate position between the bias magnet 30A and the main magnet 40A, that is, the case where the magnetic element moves in the direction of arrow B in FIG. At this time, a state almost opposite to that described above occurs.

As the magnetic element 10A and the detection coil 20A approach the bias magnet 30A, the influence of the magnetic field from the bias magnet 30A exerted on the magnetic element 10A increases, and conversely, the main magnet 40 exerted on the magnetic element 10A.
The effect of the magnetic field from A diminishes. Therefore, the magnetic element 10A
Also, when the detection coil 20A approaches the bias magnet 30A to some extent, the influence of the magnetic field by the bias magnet 30A can appear in the magnetic element 10. The positions of the magnetic element 10A and the detection coil 20A at this time are shown by B'in FIG. To be precise, even at this time, the magnetic element 10A
Although the detection coil 20A is affected by the magnetic field from the main magnet 40A, at least after the magnetic element 10A and the detection coil 20A reach the position of B ′ in FIG. 3, the bias magnet 30A changes the magnetic element 10A. The magnetic field exerted on the magnetic element 10A is more dominant than the magnetic field exerted on the magnetic element 10A by the main magnet 40A, and the influence of the magnetic field by the bias magnet 30A appears on the magnetic element 10A. To do. Magnetic element 10A
When the detection coil 20A reaches the position B ', the magnetic field applied to the magnetic element 10A is reversed due to the influence of the magnetic field generated by the bias magnet 30A, and a magnetic field in the opposite direction to the hard layer is applied, so that the soft layer becomes a hard layer. It can be magnetized in the opposite direction. The change in the magnetization of the magnetic element 10A caused by the bias magnet 30A can be detected as a pulse voltage by the detection coil 20A wound around the magnetic element 10A. The pulse voltage detected at this time is shown by b'in FIG.

After the pulse voltage b'is detected, even if the magnetic element 10A and the detection coil 20A further approach the bias magnet 30A, the state described above, that is, "the bias magnet 30A is the magnetic element is detected. The magnetic field exerted on the magnetic element 10A is more dominant than the magnetic field exerted on the magnetic element 10A by the main magnet 40A. ”Therefore, the detection coil 20A does not generate a pulse voltage. As described above, this state is maintained until the magnetic element 10A and the detection coil 20A move away from the bias magnet 30A and reach just before the main magnet 40A. This second embodiment can be used, for example, to detect which one of the two fixed objects a certain moving object is, and how close. . A liquid level switch is an application example of this configuration. here,
The main magnet and bias magnet are fixed to the ceiling and bottom of the container containing the liquid, respectively, while the magnetic element and the detection coil are attached to the float, and the float floats up and down as the liquid level changes. The upper and lower limits of the liquid level can be easily measured.

Although the wire-shaped element is used as the magnetic element in each of the above-described embodiments, the present invention is not limited to this, and various types of magnetic elements can be used.
For example, a magnetic element which is a thin film element can also be used. As described above, when the thin film element is used as the magnetic element, the detection coil may be a flat detection coil. Further, instead of the magnetic element as described above,
A single layer magnetic element can also be used. Similarly, in each of the above-described embodiments, the magnet as the magnetic field generating means is a permanent magnet, but it can be replaced with other similar means such as an electromagnet. Although the detecting means is a coil, it can be replaced with other similar means such as a Hall element, an MR element, a resonance circuit, or the like.

[0024]

EFFECTS OF THE INVENTION Depending on the position and the moving direction of an object, identifiable pulse signals can be generated and these signals can be used to identify the motion of the object. In addition, since it can be powered without a power source, it is easy to combine it with an explosion-proof type. As a result, power can be saved or safety can be improved. Further, since the pulse signal can be generated in a non-contact configuration, the device of the present invention effectively works even in a portion that is easily worn or a portion that is weak against dust or dust. Furthermore, since the device of the present invention utilizes a magnetic effect, the device can be used in water or oil.
Furthermore, chattering can be prevented.

The structure of the present invention is applied to, for example, the above-mentioned refrigerating vehicle doors, cell phone and PHS lids, notebook computers, etc. in the fields of electric and electronic equipment, and fuels in the fields of automobiles. For liquid level management of cooling water, brake oil, engine oil, etc., and as another field,
It is considered to be effective when used for liquid level microvibration, slight wind detection, liquid level switch, vibration sensor, seismometer, inclinometer, etc.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a usage example of the present device when a pulse signal generator according to an embodiment of the present invention is installed in a refrigerator.

FIG. 2 is a diagram showing a pulse voltage that can be generated when the main magnet moves to each position shown in FIG.

FIG. 3 is a diagram schematically showing a configuration of a pulse signal generator according to a second embodiment of the present invention.

FIG. 4 is a diagram showing pulse voltages generated when the magnetic element and the detection coil move to the respective positions shown in FIG.

[Explanation of symbols]

1 refrigerator 10 Magnetic element 20 detection coil 30 bias magnet 40 main magnet 60 refrigerator door 70 Refrigerator body

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masami Tanaka 5-5-23 Osaki, Shinagawa-ku, Tokyo Hirose Electric Co., Ltd. (72) Tomoaki Ito 5-5-23 Osaki, Shinagawa-ku, Tokyo Hiro SE Electric Co., Ltd. (58) Fields investigated (Int.Cl. ⁷ , DB name) H03K 3/45 G01D 5/14 G01R 33/00

Claims (7)

(57) [Claims] 1. A magnetic element capable of causing a large Barkhausen jump, a detection means for detecting a pulse generated in the magnetic element, and a first magnetic field applying a bias magnetic field for causing the magnetic element to perform a predetermined magnetization. A magnetic field generating means, and a second magnetic field generating means for applying a main magnetic field for causing a large Barkhausen jump to the magnetic element,
The magnetic element and the second magnetic field generating means are arranged in parallel with each other, and relatively move while moving in the parallel relationship to approach or move away from each other. By making the magnetic field generating means relatively close to or away from each other, the influence of the bias magnetic field by the first magnetic field generating means and the influence of the main magnetic field by the second magnetic field generating means on the magnetic element are relatively changed. To generate a pulse in the magnetic element,
A pulse signal generator, wherein the pulse is detected by the detecting means. 2. The apparatus of claim 1, wherein the first
The pulse signal generating device, wherein the magnetic field generating means is arranged in parallel with the magnetic element and the second magnetic field generating means. 3. The apparatus according to claim 1 or 2, wherein the magnetic element and the first magnetic field generating means are provided even when the magnetic element and the second magnetic field generating means relatively approach or move away from each other. A pulse signal generator that never approaches or moves away from each other. 4. The apparatus according to claim 1, wherein when the magnetic element and the second magnetic field generating means relatively approach or move away from each other, the magnetic element and the second A pulse signal generator in which the first magnetic field generating means relatively moves away from or approaches each other. 5. The bias magnetic field generated by the first magnetic field generating means according to claim 1, wherein the magnetic element and the second magnetic field generating means are relatively close to each other. The main magnetic field generated by the second magnetic field generating means becomes more dominant than the first magnetic field generating means, and a large Barkhausen jump occurs in the magnetic element due to the influence of the second magnetic field generating means. Two
When the magnetic field generating means of are moved away from each other,
A second magnetic field generating means wherein the bias magnetic field generated by the first magnetic field generating means is superior to the main magnetic field generated by the second magnetic field generating means.
A pulse signal generating device for generating the pulse at the position and detecting the pulse by the detecting means. 6. The apparatus according to claim 5, wherein the first
A pulse signal generating device in which no pulse is generated at a position other than the position and the second position. 7. The pulse signal generator according to claim 5, wherein the pulses generated at the first position and the second position have different directions or magnitudes from each other.