JPS5965211A - Frequency generator - Google Patents

Abstract

PURPOSE:To make it possible to obtain a highly accurate frequency generator, by applying a rotary magnetic field, which is synchronized with the rotation of a rotary body, to magnetoresistance elements made of ferromagnetic metal, which are divided into a plurality of units in axial symmetry or point symmertry and formed in a bent line pattern in each unit. CONSTITUTION:Magnetoresistance element units made of ferromagnetic metal PA-PH, which are symmetrically divided into 8 equal parts, are alternately arranged at angles of 30 deg. and 60 deg.. Output terminals Out 1 and Out 4 are connected by jumper wires J 1 and J 4 so as to form a bridge structure. A voltage applying terminal is V and a grounding terminal is G. Since a rotating magnetic field is applied to magnetism sensitive elements in synchronization with the rotation of a rotary body, the outputs having a constant phase difference is generated. All the outer configurations of the units are in congruence, and the arrangement of the units are in point symmetry or axial symmetry. Therefore, the uniform magnetic field is applied to the units. Uniform sine outputs are obtained from the output terminals of the magnetism sensitive elements. When a phase modulation detecting method is used as interpolation, a highly accurate frequency generator can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a frequency generator, and more particularly to a high-precision frequency generator using a magnetoresistive element utilizing the magnetoresistive effect of a ferromagnetic full-length thin film.

BACKGROUND TECHNOLOGY AND ITS POINTS In a conventional frequency generator, as shown in FIG. 1 or 2, a magnetically sensitive element 2Y such as a Hall element is arranged opposite to a circular multi-pole magnetized PG ring l. A frequency signal 7 was obtained by applying pressure to rotate in synchronization with a rotating body such as the rotor of a FGIJ Songun brushless motor, and detecting the change in the magnetic field with a magnetic sensing element 2.

However, according to the configuration of such conventional device 61.

Due to pinch unevenness in the magnetization of the FG ring l, wobbling of its outer periphery, etc., it may not be possible to rotate correctly, or attempts to downsize or increase the output frequency are physically difficult due to constraints imposed by the FG ring itself. It is possible to increase the output frequency by using a known interpolation method, but this requires obtaining a sine wave output with little distortion.
This has been difficult with conventional devices using fI' G IJ. Also, if you try to make it smaller, it is inevitable [k' G
The number of magnetized poles of the IJ ring had to be reduced.

OBJECTS OF THE INVENTION The purpose of the present invention is to eliminate the drawbacks of the above-mentioned conventional devices.
The object of the present invention is to provide a frequency oscillator which is 7 degrees i I+', can be made compact, and can employ a phase modulation detection power method as an output interpolation method.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a ferromagnetic metal magnetoresistive element divided into a line-symmetric or point-symmetric number of units and formed in a broken line pattern within each unit,
It is characterized in that the magnetic sensing elements in which the folded line patterns of adjacent magnetoresistive elements between each unit are arranged at a predetermined angle and slope are configured to rotate in synchronization with the rotation of a rotating body.

Examples Below First, the magnetic sensing element used in the present invention will be explained.
In the figure, A to 14 are symmetrical ferromagnetic metal magnetoresistive element units divided into eight equal parts, and adjacent broken line patterns PA-PH constitute the magnetoresistive element between each unit as shown in the figure (alternately 30 They are arranged at angles of 60° and 60°.

OUT□~(JUT4 is an output terminal, ■ and G are a voltage application terminal and a ground terminal. For example, the output terminals otJTi and OUT4 are connected by jumper wires Jl and J4 to form a bridge configuration.

Fig. 4 is an equivalent circuit of the magnetically sensitive element shown in Fig. 3, and if the output voltages of each terminal are divided by v1 to v4, then the element will have a pair of ``f'' mark 2.
11I TjB field f) ”/2 rotation 4jj K J
2'B = VI V2 = 'VCCsin2θ and l□ = VB V4 == K'VCCsin
It is possible to obtain two-phase outputs having a phase difference of 120° from each other (2θ - π). Therefore, these two signals DaB*
00, it is easy to generate signals having a phase difference of 120 degrees from each other using a circuit, and thus three-phase position detection signals can be obtained from one magneto-sensitive element.

FIG. 5 shows another example of a magnetic sensing element particularly suitable for the present invention, in which the adjacent fold line patterns between each unit are arranged at an angle of 45° as shown in the figure. This element is also shown in FIG. If we configure the bridge as shown in the figure and take out the output v5 to V8, g6D=V5 V6-K V(:Cs in 20D
B = V7- VB = KVoCsin (2θ-
-i) It is possible to obtain two-phase outputs OD and GEN having different phases by <90°.

In FIG. 7(a), lbl is an embodiment of the present invention, 3 is a package incorporating a magnetic sensing element shown in FIG. 5, 4 is a bipolar magnetized magnet, and 5 is a support. The support body 5 is attached to the rotary shaft 7 of the mokuro, a magnet 4 is disposed on the support body, and a magnetically sensitive element package 3 is disposed opposite to the magnet 4.

The magnets 4 are two bar magnets M, M2 as shown in FIGS.
may be provided.

Alternatively, as shown in FIGS. 9(a) and 9(b), the rotating body 8
A two-pole magnetized ring-shaped magnet 9 may be mounted inside the outer wall of the magnet, and the magnetically sensitive element pancage 3 may be provided within the magnet.

With the configuration described above, a rotating magnetic field is applied to the magneto-sensitive element in synchronization with the rotation of the rotating body, so that outputs j'l*5152 having 906 different phases as shown in FIG. 10 are generated.

As mentioned above, all of the units of the magnetic sensing element used in the present invention have the same external shape, and the arrangement of each unit is point symmetrical or IvI! Because of the symmetry, a uniform magnetic field acts on each unit. Therefore, the magnetic sensing element pan cage 3
A uniform sine wave output can be obtained from each output terminal of the unit, and if a magnetically sensitive element is used as a magnetically sensitive element in each unit, as shown in Fig. 5, the two generated Since the output has a phase difference of 906, the phase modulation detection method (for example, JP-A-57-5
14, Japanese Unexamined Patent Publication No. 57-30909, etc.) can be used, thereby obtaining high-precision frequency oscillation*a.

That is, the first and second phase outputs 2+42 are displayed as shown below.

11 =: E6 sinωt $2 == EO5in(GJt + 90) =E
OC03(c), where Eo is a direct current and '2 is the angular velocity of the rotating body.

When the above output 11+12Y phase modulation detection method is applied to the interpolation circuit, %961*j'2 is modulated as follows.

el == (E□sinωot) sinωte2
= (EO5in(ωot+90°))CO5ωt-
(E□cosGJOt) cosω, where ω0 is the angular velocity of alternating current.

Adding both modulation outputs el + e2Y, C3 = el + C4 = H□ sinω□tsin
ωt −4−E□ cosωOt cosω2EOl
cos (ωO-ω)1), and the phase of C3 depends on (ω0-ω), so by knowing the phase of C3, the angular velocity ω of the rotating body,
Therefore, the frequency of the rotating body can be determined.

As is clear from the detailed description of the invention, according to the present invention, the following excellent effects can be obtained.

(b) Since the f-th modulation detection method can be used as the output interpolation method, a highly accurate frequency generator can be obtained7)
.

(J) Since magnetic sensing elements are used in which each element unit is arranged symmetrically, a uniform rotating magnetic field acts on each element unit, and therefore a uniform sine wave output with less distortion can be obtained.

Since all that is needed is a component that rotates a small two-pole magnetized magnet placed opposite to a magnetically sensitive element unit which is made up of many confectionery units integrated into a single chip, the entire device is It can be downsized to a large extent.

[2] If a 2-pole N magnet is used, a uniform rotating magnetic field can be obtained without strict mounting accuracy to the frequency generator package.

(E) A uniform rotating magnetic field can be obtained even if the precision of the parts as a single magnet is not strict.

(f) A J-type and lightweight generator with a number of cycles can be realized.

Therefore, if this frequency generator is used in a servo system, the band of the servo system can be increased.Even if there is a torque ringer in the servo system drive motor, it can be eliminated in the servo system.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing a conventional frequency generator,
Figure 3 (al, (bl) is a schematic diagram showing an example of a magnetic sensing element used in the present invention, Figure 4 is a circuit diagram of Yi's circuit diagram, Figure 5 (al, (bl) is a schematic diagram showing an example of a magnetic sensing element used in the present invention. FIG. 6 is a schematic diagram showing another example of a magneto-sensitive element, FIG. 6 is an equivalent circuit diagram thereof, FIG. ) and FIGS. 9(a and 9b) are schematic diagrams showing other embodiments of the present invention, respectively, and FIG. 1θ is an output waveform diagram of the magnetic sensing element in FIG. Package, 4-... Magnet, 5...
Support body, 6... motor. Figure 3 Figure 4 Figure 5 (0) v Figure 5 (b) Figure 7 (G) (b) Certain Figure 8

Claims (1)

[Claims] (υ Divided into a plurality of line-symmetric or point-symmetric units,
Each unit consists of a ferromagnetic metal magnetoresistive element formed in a broken line pattern, and a magnetic sensing element in which the broken line pattern of adjacent magnetic resistance elements of each unit is arranged at a predetermined angle, and a rotating body attached to the element. and means for applying a rotating magnetic field in synchronization with the rotation of the frequency generator. (2) The element is divided into 8 units, and each of the folded line patterns has an angle of 45 degrees with respect to each other, and a set of units having an angle of 90' is connected to the output bridge of 4 sets of units. Claim f characterized by
The frequency generator according to item i1. (3) The frequency generator according to claim 1, wherein the means is adapted to rotate in synchronization with the rotation of a rotary body, and has a magnet with +2 pole magnetization. (4) The frequency generator according to claim 13 and claim 2, characterized in that the frequency generator is configured to perform interpolation using an output phase modulation detection method of the magnetic sensing element.