JPS58142270A - Magnetic sensor amplification circuit - Google Patents

Abstract

PURPOSE:To achieve a smaller size and a less weight by arranging on the same substrate or amplification circuit board as containing a magnetic sensor a resistance and conduction path to be used for a magnetic sensor amplification circuit made of the same material. CONSTITUTION:A conduction path 2, a transistor 4, a condenser 5 and a substrate for groups of magnetic sensors and resistances are arranged on a circuit board 1 and magnetic sensors 8a and 8b, resistors 9a and 9b and a conduction path 10 on a substrate 7. The resistors 9a and 9b and the conduction path 10 are made of the same material as the magnetic sensors 8a and 8b. Material used for the resistors 9a and 9b is oxidized to be made non-sensitive to the magnetic field thereby eliminating variation in the amplification factor of an amplification circuit with the magnetic field.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an amplifier circuit provided for the first purpose of compensating for the small output of a magnetic sensor.

Examples of conventional magnetic sensor amplifier circuits include the following.

Conventional example (1) A magnetic sensor amplification circuit in which a magnetic sensor and amplification circuit components are individually made to form a circuit.

Conventional example (=) A magnetic sensor amplifier circuit that is miniaturized by using a printed and fired resistor instead of the resistor used in the amplifier circuit.

However, in the above conventional example, the number of component parts is large (small Il @ not suitable for quantification. For example, the above conventional example (υ and When all are combined, the number of constituent points is 6 or more as shown in Table 1.

Here, circuit A in Figure 941 shows an am diagram using a magnetic Hayabusa sensor ld, Tr is a transistor, C is a capacitor,
t~錡 is a resistor, MRI is a magnetic sensor, and circuit B in the fa8 diagram is obtained by replacing the resistor R8 of circuit A with a magnetic sensor MR2. In addition, Figure @8 shows a mounting diagram of a conventional circuit configuration using circuit A, where (1) is a circuit board, (!) is a conductive path, and (8m) to (8c) are single resistors or Printed fired resistor, (4) is a transistor, (Xu is a capacitor, (.) is 1 magnetic sensor.

As can be seen from No. 8-, one magnetic sensor main body is much smaller than the other components such as transistors and capacitors, and is a sufficiently small component even as 2@1 point. In addition, if the resistor for the 1ζ magnetic sensor amplifier circuit is made of the same material as the magnetic sensor body, microfabrication of tens of microns or less is possible.
The resistor is sufficiently small compared to g. Therefore, the magnifying glass leaves 8
It is possible to form four resistors (or one resistor (or one resistor) and one resistor (or one resistor) on one chip, but it is also sufficiently small compared to other components such as transistors and capacitors. Even if we were to reduce the size of transistors and capacitors into chips, a single chip consisting of a magnetic sensor and resistor W44 would be smaller or equivalent.

In view of the above points, the present invention attempts to significantly reduce the weight of a small vehicle compared to the conventional magnetoelectric sensor amplifier by considering a single chip of magnetic sensor resistors III and 4 groups as one point. The present invention is realized by making part or all of the resistor and conductive path used in the i1 sensor amplification path made of the same material as the magnetic sensor and on the same substrate as the magnetic sensor or on the amplification circuit board. That purpose has been achieved.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to drawings showing embodiments thereof. Figure 4 is a circuit diagram of the first embodiment showing the configuration of the present invention, and the basic configuration is the first factor and circuits A and B in Figure 2, etc., but the area within the broken line is considered as one point. It is something that Here, 'W and 'rr are transistors, C is a capacitor, R1, R2, R8 (or MRl), and MRI is a magnetic sensor/resistor group.

The fs6 diagram is an example of Ill in the jI4 diagram, which uses eight magnetic sensors. FIG. 2 is a circuit implementation diagram showing an example of the above, and shows a state in which a magnetic sensor/resistor #4 @1 point is mounted in combination with other components.

Here, (1) is the circuit board, (!) is the conductive path, (4) is the transistor, φ) is the capacitor, (n is the magnetic sensor
Resistor group board, (mu) (8b) is a magnetic tancer, (9aX
9b) is a resistor made of the same material as the magnetic sensor, (6
) is a conductive path made of the same material as the magnetic sensor.

Diagram II is an implementation diagram showing an eighth embodiment using several magnetic sensors in the 1lil embodiment of the fIs4 diagram,
This shows a situation in which the substrate is shared with the magnetic sensor resistor group substrate. Here, (4) is a transistor, (S) is a capacitor,
(b) is a common board, (t2aX12b) is a magnetic sensor, (18aK18b) is a resistor made of the same material as the magnetic sensor, and (b) is a conductive path made of the same material as the magnetic sensor.

As shown in Table 41, the number of component parts of the magnetic sensor amplification circuit manufactured in this manner is 4 in the example ii and the example s2, which is smaller than any of the conventional examples. The eighth embodiment further reduces the number of component parts to eight, and this eliminates the need for a circuit board by mounting transistors and capacitors on the board of one point of the magnetic sensor/resistance group 4d. It is something.

By the way, since the resistor is made of the same material as the magnetic sensor, the same phenomenon as that of the magnetic sensor occurs. That is, the resistance value changes depending on the magnetic field, which changes the amplification factor of the amplifier circuit and causes the output to include a ripple component. Therefore, by oxidizing the material of the portion used as the resistor, it is possible to create a resistor group that significantly impairs the magnetic sensor function of the resistor and is not sensitive to magnetic fields. It is obvious that this allows stable output to be obtained while keeping the number of component parts to four or less.

Furthermore, even if the conduction path of the circuit is made of the same material as the magnetic sensor body, the impedance of the conduction path is sufficiently small, so that the output ripple will hardly increase. however,
If a more accurate output is desired, the conductive path can also be oxidized, resulting in a higher quality magnetic sensor amplifier circuit.

As described above, according to the present invention, it is possible to reduce the size of the magnetic sensor amplifier circuit, and therefore, the field of application of the magnetic sensor amplifier circuit can be expanded, and its industrial value is extremely large.

[Brief explanation of drawings]

Figures 112 and 112 are circuit diagrams of circuit A and circuit B, respectively, showing conventional examples, Figure 8 is an implementation diagram of circuit A configured using the conventional method, and Figure 1a4 is a circuit diagram showing the configuration of the present invention. 6 is a circuit diagram of the second embodiment in which two magnetic sensors are used in the first embodiment. FIG. 6 is a circuit diagram of the second embodiment in which two magnetic sensors are used in the first embodiment. FIG. 7 is a circuit mounting diagram showing an eighth embodiment in which two magnetic sensors are used and the magnetic sensor/resistance group board and the circuit board are shared. (1)...Circuit board, (4)...Transistor,
(5)... Capacitor, (7)... Magnetic sensor/resistance group board, (8a) (8b)... Magnetic sensor, (9
a) (9b)...Resistor, Ql)...Conducting path, (1
3)--Common board, (12aX12b)--Magnetic sensor, (18a) (18b)...Resistor, (b)...
・Conduit agent Hiroshi Morimoto Figure 1 (circuit c) Figure 3 Figure 4 Shi-m-~'' Figure 6 Procedural amendment Oshiki) % formula % 1. Indication of the case 1982 Special Permit No. 24961 2
, Name of the invention Magnetic sensor amplifier circuit 3, Relationship to the case of the person making the amendment Patent applicant name (582) Matsushita Electric Industrial Co., Ltd. 4, Agent 5, Date of amendment order (shipment date) 1982 May 25th 6. Number of inventions increased by amendment 7, attached sheet to be amended] Figure 1

Claims (1)

[Claims] 1. The resistor and conductive path used in the magnetic sensor amplification circuit are made of a material similar to that of the sensor, and are mounted on the same substrate as the magnetic sensor or in the amplification circuit. A magnetic sensor amplification path fabricated and provided on a substrate. 1. The amplification circuit according to claim 1, wherein the surface or the entire surface of the resistor used in the amplification circuit is oxidized to reduce the air resistance effect.