JPH04194602A - Magnetoelectric conversion element and magnetoelectric conversion equipment - Google Patents

Abstract

PURPOSE:To improve output of a hole element and reduce the ratio of temperature characteristics constituents occupied at the output by setting the distance between a magnet-sensing element part and a detection object to be smaller than that between a magnet and a magnet-sensing part. CONSTITUTION:A magnet-sensing part K is brought closer to a side of an arm A at a magnetoelectric conversion element 4b. Namely, when the distance be tween the magnet-sensing part K and a magnet M is set to LM and the distance between the magnet-sensing part K and an arm A is set to LA, LM becomes larger than LA. A magnetic field is not centered at the magnet-sensing part K in a state of C as compared with A but the magnetic field is centered at the arm A as is made clear from D when the arm A is brought closer, thus enabling the magnetic field which is nearly similar to B to operate on the magnet-sensing part K. Namely, an output fluctuation Vb is reduced more greatly and a fluctuation content output Vb of a bias magnetic field is en hanced, thus enabling the expression LM>LA to attain a better result as an overall temperture characteristic.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a VB magnetoelectric conversion element and a magnetic sensor device! Regarding magnetoelectric transducers that can be applied to the The developed magnetic sensor unit will now be used.

[Technical background]

In recent years, there has been a trend toward variable resistors that utilize output linearity, and emphasis has been placed on longevity. Therefore, there is an increasing demand for a non-contact potentiometer that changes resistance without coming into contact with a resistor. In addition, as mechatronics has progressed not only in industrial robots but also in consumer equipment, it has become possible to detect positions and displacements without contact using analog servo elements and positioning gears. It is also becoming important from the perspective of credibility. However, with conventional non-contact sensors, the sensor itself has been designed to suit each application, which has led to a lack of versatility.

Therefore, the cost is high and it is hardly used in the consumer field, so there is a demand for a low-cost non-contact sensor.

[Conventional technology]

Conventional magnetoelectric conversion elements include Hall elements that use the Hall principle of semiconductor materials, semiconductor magnetoresistive elements that use magnetoelectric conversion based on the semiconductor magnetoresistive effect, and ferromagnetic magnetoresistive elements that use the ferromagnetic magnetoresistive effect of ferromagnetic metal materials. A ferromagnetic magnetoresistive element that uses magnetoelectric conversion as a principle can be used.

Among magnetoelectric transducers, magnetoelectric transducers that use semiconductor materials are made of materials such as GaAs and Insb, so the number of carriers and mobility change greatly with changes in temperature, so it is difficult to maintain a good temperature. characteristics are difficult to obtain, and
It is necessary to take these measures using an external compensation circuit.

In addition, regarding the sensitivity of the semiconductor magnetoresistive element to the magnetic field, it exhibits a resistance change approximately proportional to the square in a weak i field, and a certain degree of linearity is obtained in a strong magnetic field of several hundred G (Gauss 3 or more). Therefore, in order to obtain good linearity as a magnetoelectric transducer, it is necessary to apply a strong magnetic field bias, which increases cost and complicates the shape.As a result, the range of use of the element itself is limited, and the design This is a major hindrance.

In the case of ferromagnetic thin film resistance elements, the temperature characteristics are good, but the output change is small at about 3 to 4%, and since the magnetic anisotropy effect is used, the element size cannot be reduced beyond a certain level, making mass production difficult. The effectiveness of the product is diminished and the price becomes high. Therefore, Hall elements are currently being produced in large quantities by various companies as elements that have cost advantages, and have excellent mass production effects. However, as mentioned above, currently only Gaussmeters with compensation circuits are used for continuous (analog) detection of magnetic fields because the output fluctuates greatly depending on temperature, and most of them are switch-based. It is used only for specific purposes, and when the magnetic field exceeds a certain reference value, the rgJ circuit turns ON.
This is a digital usage such as turning it off.

This is because the temperature characteristics of the Hall element itself (Hall voltage ranges from several hundred 1ill/'C to tens of thousands of pp1/'C) cannot be ignored, so position detection etc. using the Hall element is subject to considerable restrictions. In addition, the magnetic material that serves as the signal source also has temperature characteristics, so controlling both requires circuit processing for each purpose, making the design complicated.Furthermore, - for boat fishing compensation, a thermistor is used Because of the use of auxiliary elements such as auxiliary elements, problems such as the cost of the thermistor element exceeding that of the Hall element arise, resulting in an expensive device, making it unsuitable as an analog control element.

[Problem to be solved by the invention]

Magnetic detection devices using Hall elements are mostly used for switching purposes such as detecting the magnetized level 1 of brushless motors, and in analog control applications, the temperature characteristics of the Hall element may cause problems, resulting in expensive temperature As a magnetic detection element for general industrial analog control, which is only used in some Gaussmeters with a compensation circuit, it has relatively good temperature characteristics, and output changes in response to magnetic field changes can also be used as a signal magnetic field generation source. Resistance elements that utilize magnetoresistive effects have been used, although they are expensive, because it is possible to obtain a single output change that meets the purpose by adjusting the design of the magnet and element pattern.

The reason why it is expensive is that in order to increase the output change, a method is used in which a magnetic field from the outside (object side) is applied to the magnetic sensing part of the magnetic sensor to cause a resistance change, and an external magnetic field is generated. There were two points: it was necessary to install permanent magnets, etc., and the magnets and elements had to be designed for each purpose. As a result, it was not possible to deal with every situation, and the entire system had to be redesigned to suit each individual application. Therefore, there is a need for a magneto-electric change sensor that emphasizes versatility, in which the amount of its own bias magnetic field can be changed only by changes in the external magnetic material without changing the sensor part much and without having an external magnetic field generation source. has been done. In order to realize the low cost of the -layer while placing emphasis on this general-purpose use, the element itself that becomes the magnetically sensitive part must be extremely low cost and small.

In response to these demands, elements using the Hall effect are currently being produced in the tens of millions per month, and are extremely inexpensive compared to other magnetic sensors. , it would be of great benefit in industry to form a stable magnetic sensing device. However, at present, if a magnet is installed on the Hall element (sensor) side,
The change in output becomes smaller with respect to the movement of the object to be detected.

■As a result, the temperature characteristics appear to deteriorate by 1.

Since these problems arise, it has been desired to solve these problems with one simple method.

[Means to solve the problem]

The present invention relates to a magnetoelectric transducer in which at least a Hall element and a magnet placed adjacent to the Hall element are integrated by molding or the like to form a general-purpose element, and a magnetoelectric transducer in which a signal source is biased adjacent to the Hall element. A magneto-electric transducer that increases the output fluctuation due to the movement of the sensing object by setting the distance between the element magnetic sensing part and the sensing object smaller than the distance between the magnet and the sensing object, or a Hall element. The above-mentioned problems have been solved by providing a magnetoelectric conversion device in which the temperature characteristics of a ball element can be adjusted by connecting a resistor between at least two adjacent 2T terminals among four terminals.

〔Example〕

In the present invention, in magnetic detection for analog control, a Hall element, which is a low-cost element, is used in order to realize a magneto-electric conversion element and a magneto-electric conversion device that are inexpensive and have good temperature characteristics. As mentioned above, the reason why Hall elements do not have excellent temperature characteristics is that they are made of materials such as GaAS and InSb, so the number of carriers and mobility change greatly with changes in temperature. There is. This change appears externally as a change in resistance value, causing a change in output.

In general, the number of carriers with respect to temperature changes is tens of thousands of ppII/'C at a constant flow rate in the InSb system, and 2 at a constant voltage.
0001] pI/'C, whereas GaAs-based Hall elements have a small value of several hundred I) pH/'C under constant current. Therefore, if temperature characteristics are emphasized, it is better to use a GaAs-based Hall element. Most desirable.

In general, the method of changing the magnetic field for position 1 detection is shown in Figure 3 (A
), when a magnetized magnet M is attached to an arm A etc. that moves in the direction of arrow α and approaches the ball element H3, the Hall element H3 changes in the way it comes out. As shown in , the soft magnetic arm A and the bias magnet Mt! - relative position 1 with the provided ball element H5;
Type b (1c of the present invention) that detects magnetic field changes due to misalignment
(main constituent parts of the lit conversion element). In the case of type a, the installation of the magnet M is likely to cause misalignment and misalignment of the ball element HS, making assembly difficult; however, since it can be detected from the zero magnetic field region, the change in the output of the ball element HS ( On the other hand, in type b, the magnet M and arm A have no choice but to separate, so
Although the output is lower than type a, it is advantageous in terms of assembly. Note that even when arm A is made of a soft magnetic material such as iron, output changes occur, so it is desirable to make the output change larger in this type b.

In the above configuration, the temperature characteristics correspond to the temperature characteristics of the Hall element HS and the magnet M. Therefore, as magnet M,
Samarium cobalt type with small temperature characteristics (approximately 300pp
In terms of the temperature characteristics of the Hall element Is and magnet M, a GaAs-based Hall element is used to minimize the temperature characteristics of the Hall element H3, and the influence of temperature changes on the input resistance is minimized. With constant current operation that can remove -1000
1) l) It is possible to make it about 11/'C (=K). Therefore, under these circumstances, considering the temperature characteristics for each type, in the configuration of type a, if the output fluctuation in the presence or absence of a magnet is Va, then the output fluctuation AVa' (=VB- ni-aT) (however, a
T is the amount of temperature change), that is, the fluctuation rate of the temperature characteristic with respect to the amount of output change is ΔVa÷V a = K-T...
...C1). However, in type b, a bias magnetic field is already acting on the Hall element itself,
An output fluctuation vb occurs depending on the amount of this magnetic field. On the other hand, arm A7! l (The amount of variation when it comes closest is captured as the change output AVb of this bias magnetic field, and is generally smaller than type a. At this time, type b
A temperature characteristic output change ΔVb1 (=v)l·K-AT) with respect to the output occurs due to the bias magnetic field. At this time, the value that appears as the actual temperature time characteristic is effective against the output difference due to the presence or absence of arm A, so type b
Output fluctuation A due to temperature change for output change amount 4Vb
vbt is "'bt' AVb = (Vb ÷avb)K-aT...
...(2).

Here, (Vb÷aVb>) is the bias magnet M in the arrangement shown in FIG. Since the output when there is no arm is larger than the output change AVb when arm A approaches, (Vb/aVb
>≦1, and this arrangement is difficult to realize. Therefore, the temperature characteristics shown in FIG. 2(B) are inferior.

Therefore, in general, applications have been attempted in the past with the configuration shown in FIG. 6A, which is disadvantageous in terms of assembly cost. In order to improve the temperature characteristics, it is also possible to use a thermistor element T with a negative temperature coefficient as shown in Figure 2, or a nickel resistor (resistor) or manganin resistor with a positive temperature coefficient. be. In this case, the price of the thermistor element, etc. increases, but also the curvature of the characteristic curve of the thermistor etc. does not match the curvature of the Hall element, so compensation cannot be achieved over a wide temperature range.

Therefore, in the element (device) of the present invention, we aim to reduce the temperature characteristics by using the arrangement and configuration shown in Fig. 3 (8), which originally has a large cost advantage. The aim is to more easily realize analog servo control of elements (devices).

Hereinafter, the magnetoelectric transducer and the magnetoelectric transducer of the present invention will be explained in more detail. In the configuration shown in FIG. 3fB), the first step in improving the temperature characteristics is to increase the amount of variation 4Vb in the Hall element output when arm A approaches the closest.

Figures 1 (A) to (D) show a bias magnet M and a magnetic material detector (hereinafter referred to as "arm") in the magnetic sensing part of the Hall element HS.
Examples of the configuration of the magnetoelectric transducer of the present invention are shown, respectively, with respect to the relative arrangement of A (also referred to as A). Same figure (A)
, (B) shows a configuration example (magnetoelectric conversion element 4a) in which the magnetically sensitive part K is brought closer to the magnet M side, and the distance between the magnetically sensitive part and the magnet M side is the distance between the LMv magnetically sensitive part and the arm A. If LA is LM<LA ・・・・・・・・・・・・・・・・・・
・・・・・・・・・(3) When the state without an arm is shown in the same figure (A), it can be seen that the magnetic field strongly acts on the magnetically sensitive part K of the Hall element H8. Ru. Then, as shown in FIG. 3B, when arm A approaches the Hall element HS, the magnetic field distribution changes because arm A, which is a magnetic material, is regarded as part of the magnetic circuit.

Figures 1 (C) and (D) are configuration examples (magnetoelectric conversion element 4b) in which the magnetic sensing part K is brought closer to the arm A side, that is, LM > LA.
・・・・・・・・・・・・・・・・・・
......(4), in this case as well, as above,
Figure (C) shows the configuration and magnetic field distribution without an arm, and Figure fD) shows the configuration and magnetic field distribution with an arm. In the state shown in Figure (C), the magnetic field is not concentrated in the magnetically sensitive part K than in Figure fA), but when arm A is brought closer, as is clear from Figure (D), the magnetic field is Since the magnetic field is concentrated, a magnetic field having substantially the same shape (close to) as shown in FIG. 8 (8) also acts on the magnetic sensing part K at the same time. That is, Vb in the second formula is reduced more, and A
It has a shape with increased Vb.

Therefore, as for the overall temperature characteristics, better results can be obtained with a configuration that satisfies the fourth equation.

Specifically measured values are shown in FIGS. 4(A) to 4(D), respectively. In addition, as the bias magnet M, a TS-
24 (using marium cobalton manufactured by Toshiba, the magnetic field estimated from the strength of the magnetic field generated in each part of the equal Hall element H3 (Hall element output vI) and the magnetic field measured with a Gauss meter) (unit [KCl)] ) is entered. In addition, in the same figure (^) and (B), LM = 0.15I
I11. LA = 0.45n+n, and the same figure (C)
, (D), the Hall element H8 of the same figures (^) and (B) is installed upside down. In addition, as the Hall element H8, we use the VHG601 series made by JVC (Japan Victor), which is small in the existing mass-produced products, use iron yoke Y for the magnet base, and arm A made by Nippon Steel (EG).
c-E-20/20) was used.

As is clear from these figures, (A) and (C)
When comparing the magnetic field conditions at points ■, ■, and ■ in the state without arm A, only the magnetic field at point ■ (judged by the Hall element output Vb) changes, and the size of LM is small (A). A higher magnetic field acts on the magnetically sensitive part. That is, Vb
The value of is large, which is disadvantageous in terms of temperature characteristics. Constant voltage g1
Under 0 nA, the Hall probe output Vb is (A) [1l
l) Ill contract approximately 550iV, (C) Approximately 3 with the configuration shown in the figure
They each showed 101V. In addition, in the comparison between (B) and (D) of the same figure, the variation AVb of the Hall element output was measured.
The fluctuation value of vb→190[V was obtained.

From the above results, the explanation in FIG. 1 is verified. That is, in FIG. 4(A) where LM<LA, Vb=aVb cape 4.4, and in FIG. 4(C) where LM>LA, Vb÷, avb cape 1,6.

In either case, the temperature characteristics of the original Hall element itself are deteriorated, but by adopting a configuration that satisfies the fourth equation, it can be improved considerably.

In the combination shown in Figure 4 (D), the maximum temperature characteristic is approximately 16
001) pl/'C. Therefore, in order to employ a bias magnet and reduce assembly cost without deteriorating the temperature characteristics, it is first necessary to satisfy the fourth equation as the minimum condition. However, since there is a manufacturing limit to reducing the distance MLA, the present invention further requires means for improving the temperature characteristics of the magnetic detection device (magnetoelectric conversion element) 4b.

One of the methods will be described next.

First, the Hall element H3 is placed in the state shown in FIG. 4(C) with a bias magnetic field applied, and the output of the Hall element H8 is amplified using the differential amplifier circuit 5 having the configuration shown in FIG. OA to OA3 are operational amplifiers. FIG. 6 shows the fluctuation state of the output at the output terminal -I of the differential amplifier circuit 5 due to temperature. Each resistor used is designed to reduce temperature characteristics.
Metal film resistor (±100ρρ using Matsushita Electric #1)
It was within 11/'C. The temperature characteristic appears as the sum of the Hall element H8 and the magnet M, and is about 800 ppm/
“It was C.

A convenient equivalent circuit of the Hall element is shown in FIG.

In this figure, the magnetic field direction is perpendicular to the plane of the paper, and the north pole is on the upper side. This circuit is applied to the configuration shown in FIG. 4(C), and the terminal pc is a terminal that causes a potential shift in the child direction, and the terminal pd is a terminal that causes a potential shift in one direction, compared to when no bias is applied. When a constant current is supplied to the terminal Pa, the GaAs-based Hall element has temperature characteristics as shown in FIG.

In the figure, the solid line is the value on the +(Pc) 4-terminal side, and the broken line is the value on the -(Pd) terminal side.As can be seen from this figure, as the temperature rises, both the Pc and pd terminals have a value relative to the Pb terminal. However, since the rate of increase in the output of the Pd terminal is somewhat higher than that of the PC terminal, looking at the differential output between the Pc terminal and the P terminal, the output tends to decrease. This difference appears as a temperature characteristic, and represents a decrease in sensitivity due to an increase in the temperature of the Hall element.

However, this output shows the same behavior as an external output even with fluctuations in the power supply, that is, the power supply current (
or voltage) increases or decreases, the output also increases or decreases. If we consider this from the equivalent circuit shown in Figure 7 above, we can simply turn the power supply
If only the current flowing through the resistors Rδ and Ra'' is made smaller, the current flowing through the resistors Rδ and Ra'' also decreases in proportion to the variation in the power supply @current I. In this case, it is difficult to affect the temperature characteristics themselves;
When a constant current I is applied as shown in the figure, and a variable resistor VR is inserted and connected between the Pc terminal and the Pd terminal, the current Ia flowing through the resistor Ra is reduced compared to the configuration shown in FIG. On the other hand, the IH current Ia' flowing through the resistor Ra' increases, and the current ratio flowing inside the Hall element collapses.As a result, it can be interpreted that power supply fluctuations occur differently for the resistance inside each Hall element. Therefore, the temperature characteristic of the Hall element shown in FIG. 7 will be different from that of the Hall element shown in FIG.

Experimentally, in order to increase the current increase in the resistor Ra'',
When the value of the variable resistor VR shown in FIG. 9 is decreased, the terminal Pd
, the negative temperature characteristic component acts strongly and acts in the direction of reducing the slope of the fluctuation line (characteristic) shown by the broken line in FIG. 8. This action also reduces the current 1a flowing through the resistor Ra, so that under constant voltage, the current Ia is constant in an equivalent circuit for convenience, so there is a similar effect. Also, the terminal Pc II! It also works on I, but it appears more prominently on the terminal P side, and after a certain resistance value of the variable resistor VR,
The slope of the fluctuation line of terminal Pd becomes smaller than the fluctuation line of terminal Pc, and the GaAs-based Hall element, which had previously shown a negative temperature coefficient, now has a positive temperature coefficient due to the introduction of the variable resistor VR. It becomes like this.

This effect is achieved by reducing the current Ia while keeping the current Ia' constant, or by increasing the current 18' while keeping the current Ia constant, so it is not limited to the configuration shown in FIG. , as shown in Figure 10 (^), the terminal Pa
, even if inserted and connected between Pc. Also, the same figure (E)
As shown in FIG.
In the case opposite to the magnetoelectric transducer (device) 4b shown in ), the above condition is satisfied by connecting the variable resistor VR as shown in FIG.
As shown in D), a variable resistor VR, ~V is connected between each terminal Pa and Pd.
Place Rum.

Although it is possible to balance the current and eliminate temperature characteristics by connecting it, it is not preferable because it complicates the circuit and increases costs.Furthermore, the fluctuation of the terminal PC shown in FIG. For a Hall element whose variation is larger than , it is the same as changing the polarity of the magnet in the above example, and the same holds true.

FIG. 11 shows the variable resistor VR in the configuration shown in FIG. 9 above.
+ (Pc) terminal (solid line) when the resistance value of is set to 31Ω
It is a characteristic diagram showing the temperature characteristics of and=(Pd)f4 (broken line). As can be seen from this figure, as the temperature rises, Pc,
The rising trends of both Pd terminals are almost completely consistent. This is under the condition where the bias magnetic field shown in FIG. 4(C) is applied, and the variable resistor VR is, for example, a commercially available RJ
-6P resistor is used.

Further, FIG. 12 is a characteristic diagram showing the temperature characteristics of the differential output of the terminals Pc, p, . . . with and without the variable resistor VR (Ω at 31). As can be seen from this figure, in the case of no variable resistance, the temperature characteristics of the Hall element H3 and the magnet M
However, by connecting the variable resistor VR, the temperature characteristics are improved to about 1/10.

FIG. 13 shows an amplifier circuit 5 in which a variable resistor VR is connected between the terminals pb, p, as shown in FIG. 9 in the circuit shown in FIG. FIG. 14 shows the fluctuating voltage for the VHG601 series manufactured by JVC as the Hall element H3.
J-Zunite input resistance Ri LF650Ω, output resistance RO
→I am using a 1200Ω one.

Also, at this time, the vb at +20℃ with no arm is approximately 400.
mV, the amount of variation 1iVb when the arm is closest is approximately 190m
It is V.

In Fig. 14, the resistance value of the variable resistor VR is approximately 31Ω.
, the value Vi at the output terminal -1 of Avb amplified by the amplifier circuit 5 is approximately 1450 mV.
(= amplified output of A V b), so by simply comparing this output variation with the temperature characteristic output variation 1, a Vt (approximately -11 mV), b V t / Vi
≠-〇, 8%, the fifth without connecting variable resistor νR
In the case shown in the figure, it has a temperature characteristic about 10 times this, so the first
It can be seen that the configuration shown in Figure 3 has sufficient effects.

Furthermore, when the value of the variable resistor VR is increased from 31Ω to 36Ω, the minimum value of the temperature characteristic curve moves to the high temperature side, as shown by the dotted line in Figure 14, and in the room temperature range, as the temperature rises. Has negative temperature characteristics. On the other hand, change the variable resistance value from 31Ω to 2
When the resistance is lowered to 7Ω, the opposite trend is shown as shown by the broken line in FIG. In this way, by adjusting the value of the variable resistor VR, the temperature characteristic curve can be freely changed beyond 0. Therefore, regardless of the type and quality of each element, by adjusting the variable resistor value. It can be seen that the temperature characteristic curve can be adjusted to the optimum value.

Therefore, it can be understood that this is an inexpensive and excellent method for countering the temperature characteristics of a Hall element detection device with a bias magnet (this also holds true without a bias magnet).
In addition, regarding changes in the input and output resistance values of Hall elements, the resistance value decreases by approximately 10%.

When the value of the variable resistor νR is kept constant (31Ω) for the increase, the minimum value of the solid curve in Fig.
℃, but with a deviation of approximately ±20℃, the output fluctuation amount Av
The variation range of t at 20 to 60° C. is only about 1.5 times. Therefore, the present invention is at a level that can be adequately handled even with the current production form of Hall elements, and can be said to be a realistic method for improving temperature characteristics.

However, this method of adjusting temperature characteristics is handled by balancing the internal current of the Hall element when it is receiving a constant bias magnetic field, so the optimum value of the variable resistor VR may vary due to fluctuations in the bias magnetic field. It has the characteristic of changing. That is, as shown in FIG. 4(D), when the arm A approaches, the magnetic field that affects the Hall element H3 increases, and the bias magnetic field of the upper Hall element HS appears to increase. Then, as shown in Figure 15, compared to the temperature characteristics without the arm (solid line), when arm A approaches, the temperature characteristics change as shown by the dotted line, and the amount of magnetic bias of Hall element H3 increases. , the temperature characteristics increased in the negative direction. Even in this situation, the temperature characteristics are improved compared to the case without variable resistor VR, which is shown by the broken line. Therefore, in the initial bias design, it is best to select a point approximately midway between the maximum output point and the minimum output point in the actual application, and determine the value of the variable resistor VR at this point. Fig. 16 (A) shows the optimum value of the variable resistance νR for the Hall element output when the arm Atfi approaches, using the Hall element H3 used in the measurement in Fig. 14, which is a countermeasure against temperature characteristics. It can be seen that as the 6-hole element output vH increases, the variable resistance value that provides the fin temperature characteristics in that magnetic field tends to decrease. Here, it is assumed that the output fluctuation occurs at the maximum, and with arm A,
Consider the output point approximately halfway between the two states of nothing as the magnetic bias point α of the Hall element, and set the variable resistance value at that time to approximately 25Ω. The state of each temperature characteristic with an arm, without an arm, and at the magnetic bias point α under such settings is shown by curves (broken lines) C, B, and A in FIG. 16(B), respectively. Calculating based on the values in this table, at the set point α of the variable resistor VR,
8 for the output fluctuation amount aVb (approximately 1450mV)
The temperature characteristic is approximately ±0.3% for a temperature fluctuation of 0°C (solid line A).On the other hand, the fluctuation at the lowest magnetic field without an arm changes as shown by dotted line B, and is approximately ±1. 4%, and the variation at the highest magnetic field applied by the arm is approximately ±0.9 as shown by the broken line C.
The change was %. In other words, even if the maximum temperature characteristic fluctuation is taken into account, it is the dotted line B, and if this is considered in terms of the temperature characteristic coefficient, it is approximately 3.
The temperature characteristic of the Hall element itself is 600 p1) Im/''C, which is approximately 50 ppH/'C, but the temperature characteristic is more stable than that value, and the effect of the present invention is verified.

On the other hand, when using iron material, the thickness of arm A is as follows:
At approximately 0.05+111, the output fluctuation amount aVb is approximately maximized. That is, it has been found that even a fairly small arm is sufficient to cause output fluctuations, and this makes it possible to respond to miniaturization of the device.

As described above, the Hall element H8 has a bypass variable resistance V
Temperature characteristics can be reduced by simply connecting R.
A Hall element (magnetoelectric conversion) device with a bias magnet that is inexpensive to assemble and has good temperature characteristics has been realized.

Therefore, the fact that the Hall element with a magnetic field signal source has been able to increase the output and further improve the temperature characteristics means that the Hall element, which was conventionally used only in the field of detecting only the position of a magnet, has been replaced by a simple soft magnetic material. Since the position of the material can be detected simply by bringing the material close to the Hall element, it has become possible to construct an analog control device at an affordable price for both general control and consumer use.

FIG. 17 shows various embodiments of the Hall element (magnetoelectric conversion) device of the present invention, and the method of use will be explained with reference to this.

Figure (A) shows that by rotating the spiral iron yoke U in the direction of the arrow γ, the hole is changed by changing the position of the iron yoke U at that time (distance between the edge of the iron yoke U and the element 10 of the present invention). It is a potentiometer-like device that has a structure that changes the output of the element. In addition, in the same figure (B), the element 10 of the present invention is installed under the iron shaft J whose tip is partially processed as shown in the figure, and the output of the Hall element is changed by rotation of the iron shaft J in the direction of the arrow γ. , is a mechanism that controls the degree of rotation (rotational speed and phase) of the shaft. This is also a potentiometer-like device, but the system direction can be configured to be smaller than that shown in FIG.

In addition, in the same figure (C), the position of the iron yoke F is detected by moving the iron yoke F having the apex angle θ as shown in the direction of the arrow δ to cause a change in the output of the Hall element, thereby detecting the position of the iron yoke F. This is a scale usage. Furthermore, the figure fE) is
The inclination of the pendulum G is detected by detecting the change in the output of the Hall element due to the change in the distance d between the peripheral edge of the pendulum G and the element 10 when the iron pendulum G is swung in the direction of the arrow ε. . In this case, the distance r1 from the swing center point 0 of the pendulum G to each peripheral edge. r2. r3 is formed so as to gradually become longer, for example, rl<r2<r3. Furthermore, in the same figure (D), the movement of the iron arm A attached to the iron shaft J in the direction of the arrow ζ is detected by detecting the output change with the element 10 placed close to the bottom of the arm A.
This allows minute rotation control. As shown in each of these Examples, the device 10 of the present invention can be used in a wide range of fields as an inexpensive sensor with good temperature characteristics.

FIG. 18 shows a magnet built-in type Hall element in which the magnet M and the Hall element H3 are molded into an object. This has the advantage that the distance MLA between the magnetic sensing part and the arm and the distance LB between the magnet and the angry magnetic part can be easily controlled, and that the number of man-hours for assembling the magnet can be reduced.

Such an element is only possible if it has a built-in bias magnetic field and improved temperature characteristics.

Other than that, assuming the Hall element is constant, the output fluctuation I
By setting aVb as the maximum displacement when the arm is closest to the element 10, determining a variable resistance value at the center when no arm is present, and connecting a fixed resistor having that resistance value between the two terminals of the Hall element. , it is also possible to create an integrated element.

Thereby, as a general-purpose element, mass production effects can be achieved and costs can be reduced.

In addition, by installing a thin plate made of non-magnetic material such as ceramic with excellent wear resistance on the surface of the Hall element, the arm can be brought into direct contact with the element 10, and the output fluctuation amount A V b can be used up to its maximum value. The element (device) can also be made by integral molding or the like. FIG. 19 shows an example of such a device 11, in which a window 8 is formed in a non-magnetic substrate 7 by etching or the like, and a Hall element H5 is embedded therein. Note that the surface H81 of the Hall element HS is placed several tens of μm deeper than the surface 7a of the substrate 7, so that it is difficult to come into direct contact with an external object. By forming in this way, the output of the Hall element device 11 with bias magnet M can be maximized.

Furthermore, in addition to this, a Hall element H3 is buried in a hole drilled in the ceramic substrate (7), and a variable resistor VR, an amplifier circuit 5, etc. are installed on the back side opposite to the side to be detected. It is also possible to construct a device that is compact, durable, and easy to use by using an assembled circuit-integrated element (not shown).

Furthermore, by using a rare earth magnet such as a samarium cobalt magnet, a strong magnetic field can be applied to the Hall element H8, and the influence of external noise can be minimized. At this time, temperature characteristics can also be set favorably, making it possible to construct an excellent magnetoelectric transducer.

〔effect〕

According to the magnetoelectric transducer and magnetoelectric transducer of the present invention, the assembly cost can be reduced by integrating the 6-hole element and the magnet, which have the following various excellent features.

■By bringing the magnetic sensing part of the Hall element with a signal magnet closer to the object to be detected, the output of the Hall element (device) can be greatly improved, and the proportion of the temperature characteristic component in the output can be reduced.

■ By connecting a bypass (variable) resistor between at least two adjacent terminals of the four terminals of the Hall element, the temperature characteristics can be adjusted, and fluctuations in temperature characteristics can be significantly reduced, making it possible to The temperature characteristics were improved compared to the original ones. This has made it possible not only to apply Hall elements to analog control, but also to a wide range of applications in control devices and position detection devices.

■ A magnet that has relatively good temperature characteristics and generates a high magnetic field, such as a samarium-cobalt magnet, can be used as a signal source in a small volume similar to a Hall element, and can be used as a signal source to provide a sufficiently large magnetic field (therefore, it is also resistant to external magnetic field noise). It can also reduce costs.

■Since the structure is equipped with a signal source, it is easy to detect soft magnetic materials such as iron. Therefore, it is possible to detect the position of any magnetic part of each control device, which simplifies #1 construction and leads to cost reduction.

■Since the temperature characteristics have been improved, it is possible to construct a simple potentiometer using a Hall element, making a great contribution to industry. ■It has become possible to realize a new element that integrates a signal source magnet and a Hall element, which not only reduces costs, but also
This also made it possible to create a new general-purpose magnetic detection element.

[Brief explanation of the drawing]

Figures 1 (A) to (f)) are explanatory diagrams of the configuration and output improvement principle of each embodiment of the magnetoelectric conversion element of the present invention, and Figure 2 is a circuit for explaining the conventional temperature characteristic improvement of a Hall element (device). Figures 3(A) and 3(B) are explanatory diagrams of the main components and detection principle of comparative examples and examples of the magnetoelectric transducer of the present invention, respectively, and Figures 4(A) to (D) are respectively Explanatory diagrams showing specific numerical analysis for each configuration example in Figures 1 (A) to (D), Figures 5 and 1
3 is a circuit diagram of the first and second embodiments of the magnetoelectric conversion device of the present invention in which an amplifier circuit is connected to a Hall element, FIG.
4 and 15 are characteristic diagrams showing the temperature characteristics and examples of changes thereof of the first and second actual fiber example devices, respectively, and FIG. 7 and FIG. A convenient equivalent circuit diagram of the Hall element part of the second embodiment device, FIG. 8 is a temperature characteristic diagram of the pole element (rii electric conversion element before improvement), and FIG. 10 (A) to (0)
9 is a convenient equivalent circuit diagram of the Hall element portion of each of the other embodiment devices with respect to the equivalent circuit of FIG. 9, and FIG. 11 is a temperature characteristic diagram of the output voltage of the device of the present invention,
FIG. 12 is a comparison diagram of the temperature characteristics of the output of each embodiment of the device of the present invention, FIG. B) is a characteristic diagram showing the temperature characteristics of the output with respect to variations in the magnetic field, FIGS. 1'7 (A) to [0] are perspective views showing each embodiment of the device of the present invention, and FIG. Figure, 1st
8 and 19 are a side view and a perspective view, respectively, showing still other embodiments of the magnetoelectric conversion element of the present invention. 4 a, 4 b, 10-12 - magnetic conversion element, 5... amplifier (differential amplification) circuit, 7... non-magnetic substrate, 8...
Window, 21-25... Magnetoelectric conversion device, A... Arm (
magnetic material detection object), F, tJ...iron yoke, G...iron pendulum, H3...Hall element, J...iron shaft, K...
・Magnetic sensing part, M...bias magnet, OA, ~OA3・
...Operation amplifier (op-amp), Pa-Pd...Hall element terminals, VR...variable resistor, Y...iron yoke. Patent applicant: Victor Japan Co., Ltd. (A (δ)
W1 diagram (, 4) (B) 4 throats (A) (B) (C) < v > 〃β (E) 10% y1. figure

Claims (5)

[Claims] (1) For a magnetoelectric transducer with a signal source adjacent to a Hall element, by setting the distance between the element's magnetically sensitive part and the sensing object to be smaller than the distance between the magnet and the magnetically sensing part, the sensing object can be A magnetoelectric conversion device characterized by large output fluctuations due to movement. (2) At least two adjacent terminals of the four terminals of the Hall element
A magnetoelectric conversion device characterized in that temperature characteristics of a Hall element can be adjusted by connecting a resistor between terminals. (3) A magnetoelectric transducer in which at least a Hall element and a magnet placed adjacent to the Hall element are integrated by molding or the like to form a general-purpose element. (4) In the magnetoelectric conversion element according to claim 3, a resistor for improving temperature characteristics and a circuit for output signal amplification are also integrated,
Alternatively, a magnetoelectric transducer characterized in that output signal wiring from the magnetoelectric transducer is formed short. (5) A magnetoelectric transducer characterized in that the magnetic sensing part side of the Hall element or its periphery is surrounded by a nonmagnetic material whose wear resistance is higher than that of ordinary molding resin.