JPH037908B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plurality of coils in which permanent magnets are arranged in a plurality of coils wound in a manner that crosses each other, and an electric signal corresponding to the output of a sensor is supplied to the coils. This invention relates to a crossed coil type indicator in which a permanent magnet is rotated by a sensor to indicate a value corresponding to a physical quantity detected by the sensor, for example, temperature.

This type of indicating instrument can be seen, for example, in the water temperature gauge of a car; this type of water temperature gauge keeps the indication constant within the temperature range in which the engine is normally operating, so that it can be used to In order to avoid unnecessary worries, for example, as shown in FIG. 5, the indicator angle θ is made constant in a predetermined water temperature range of 82° C. to 110° C., so that the water temperature has a temperature-to-day characteristic.

[Conventional technology]

In order to obtain an indicator having water temperature-scale characteristics as shown in FIG. 5, a circuit configuration as shown in FIG. 6 has conventionally been adopted.

In Figure 6, L ₂ and L ₃ are coils that are parallel to each other but wound in opposite directions and connected in series as shown in Figure 7, R is a resistor, and R _S is a thermistor-like coil. It is a temperature-sensitive resistor with negative temperature characteristics,
Coils L ₂ and L ₃ and resistors R and R _S constitute a bridge circuit, and a series circuit of a Zener diode ZD and a coil L ₁ is connected between these interconnection points A and B. The coil L ₁ is wound so as to intersect with the coils L ₂ and L ₃ .

As described above, the value of the resistance R _S changes as the sensed temperature changes, but when the water temperature is low and the value of the resistance R _S is large, the Zener diode ZD conducts in the direction of the arrow, and the coil L ₂ , In addition to the magnetic field L ₃ -L ₂ caused by L ₃ , a magnetic field -L ₁ is generated by the coil L ₁ , and these combined magnetic fields X act on the rotating permanent magnet M to change the position of the pointer S as shown in FIG. It has been decided.

Under conditions where the water temperature gradually rises and the bridge circuit is in equilibrium, no current flows through coil _L1 ;
Only a magnetic field L ₃ -L ₂ due to L ₂ and L ₃ is generated, and the pointer S indicates a position corresponding to the direction of the magnetic field.

As the water temperature rises further, the value of the resistor R _S decreases, and accordingly the Zener diode ZD becomes conductive in the direction of the arrow, generating a magnetic field +L ₁ in addition to the magnetic field L ₃ -L ₂ . Thus, the pointer S gives instructions according to the direction of these combined magnetic fields Y.

In the temperature range where the potential difference between the connection points A and B is only below the Zener voltage which does not conduct the Zener diode ZD, only the magnetic field _L3 - _L2 is generated, and the pointer S continues to point at a fixed position. The characteristics shown in FIG. 5 are obtained.

[Problem that the invention seeks to solve]

In the above-mentioned conventional indicator, a bridge circuit is used, and the range in which the pointer's indication is kept constant is determined only by the Zener diode ZD, so if there is variation in the Zener diode ZD, The range in which the pointer continues to point at a fixed position changes, making it impossible to obtain sufficient indication accuracy.Also, the indication changes due to variations in parts such as the resistor R and coil _L1 , and the slope of the characteristic curve, in particular, There were problems such as it being extremely difficult to change.

[Means for solving problems]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a crossed coil type indicating instrument which solves the above-mentioned problems of the conventional instruments, allows the characteristic curve to be changed relatively freely, and improves the indicating accuracy.

[Means to solve the problem]

In order to achieve the above object, the cross-coil indicator according to the present invention has a permanent magnet arranged in a plurality of coils wound in a manner that crosses each other, and an electric current corresponding to the output of a sensor is supplied to the coil. A crossed coil type indicator in which a permanent magnet is rotated by a signal to indicate a value corresponding to a physical quantity detected by the sensor, and the first coil is always excited to generate a constant magnetic field. , second and third coils wound so as to generate magnetic fields in mutually opposite directions that intersect with the magnetic field generated by the first coil, and electricity having a size corresponding to the physical quantity detected by the sensor. first and second actuation circuits that receive a signal and operate in first and second ranges of the magnitude of the electric signal that do not overlap with each other, the first actuation circuit being operable in the first and second ranges of the magnitude of the electric signal; The second coil is energized in response to an input electric signal having a magnitude of , to generate a magnetic field having a magnitude inversely proportional to the input electric signal, and the second actuating circuit has a magnitude in the second range. The third coil is excited in response to an input electric signal to generate a magnetic field whose magnitude is proportional to the input electric signal.

[Effect]

As described above, the first to third coils are configured to be excited independently, and the first to third coils are selectively actuated to excite the second and third coils, respectively. Since the pointer is indicated by the composite magnetic field of the magnetic field generated by the second or third coil and the magnetic field generated by the first coil, the first
By adjusting the characteristics of the second actuating circuit, adjusting the current flowing through the first coil, etc., the characteristics can be freely changed, and high precision can be achieved.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, and in the figure, 1 is a +B which is supplied from an automobile battery and fluctuates in the range of, for example, 11 to 16V.
This is a constant voltage circuit that stabilizes the voltage and outputs a constant voltage. Reference numeral 2 denotes a bias circuit that constantly supplies a constant current to the coil L ₁ based on the voltage supplied from the constant voltage circuit 1 to excite it, and generates a magnetic field indicated by φ ₁ in FIG. 3 is a low-temperature coil that operates in a predetermined temperature range from low temperatures to, for example, +82°C, and excites the coil _L2 by passing a current inversely proportional to the temperature to generate a magnetic field with a magnitude inversely proportional to the temperature, as shown by _φ2 in Figure 2. This is the operating circuit. 4 operates in a predetermined temperature range, for example from 110℃ or 115℃ to a high temperature range, and excite the coil _L3 by passing a current proportional to the temperature, creating a magnetic field proportional to the temperature as shown by _φ3 in Fig. 2. This is a high temperature operating circuit that generates heat. The magnetic field φ ₁ is orthogonal to each of the magnetic fields φ ₂ and φ ₃ which are directed in opposite directions. 5
is a temperature-sensitive resistor whose resistance value changes according to temperature changes.
This is an input circuit that compares the value of R _S with a reference resistance value and converts it into a voltage.

The operation will be explained using the above configuration.

FIG. 1 is a block diagram showing one embodiment of the present invention, and in the same figure, 1 is a voltage supplied from an automobile battery, which varies in the range of, for example, 11 to 16V.
This is a constant voltage circuit that stabilizes the B voltage and outputs a constant voltage. 2 is a bias circuit that constantly supplies a constant current to the coil L ₁ as the first coil based on the voltage supplied from the constant voltage circuit 1 to excite it, and generates a magnetic field indicated by φ ₁ in Fig. 2. . 3 operates in a predetermined temperature range as a first range from a low temperature of, for example _, 50°C to, for example, +82°C, and excite the coil _L2 by passing a current inversely proportional to the temperature.
This is a low-temperature operating circuit as a first operating circuit that generates a magnetic field with a magnitude inversely proportional to the temperature.
4 operates in a predetermined temperature range of the high temperature range, for example from 110℃ or 115℃ as the second range, and excite the coil _L3 by passing a current proportional to the temperature, which is proportional to the temperature as shown by _φ3 in Fig. 2. This is a high temperature operating circuit as a second operating circuit that generates a magnetic field with a magnitude of . The magnetic field φ ₁ is orthogonal to each of the magnetic fields φ ₂ and φ ₃ which are directed in opposite directions. Reference numeral 5 denotes an input circuit that compares a temperature-sensitive resistor R _S value whose resistance value changes according to temperature changes with a reference resistance value and converts it into a voltage.

The operation will be explained using the above configuration.

The bias circuit 2 causes a constant current to flow through the coil L ₁ serving as the first coil regardless of the temperature, thereby generating a constant magnetic field φ ₁ (FIG. 2). Assume that this magnetic field φ ₁ is oriented at 45° as shown in FIG.

In the first low temperature range of 82° C. or lower, the second operating circuit, the high temperature operating circuit 4, does not operate, and only the first operating circuit, the low temperature operating circuit 3, operates. The low-temperature operation circuit 3 excites the coil L ₂ by causing the maximum current to flow through the coil L ₂ in response to the input electric signal when the temperature is below 50°C, and the magnetic field φ ₁ generated by the bias circuit 2 and A magnetic field φ ₂ of the same magnitude is generated in coil L ₂ . The low temperature operating circuit 3 also operates as the temperature rises above 50°C.
A current that gradually decreases in accordance with the input electric signal is passed through the coil L ₂ to excite the coil L ₂ , and a magnetic field φ ₂ (Fig. 2) that gradually decreases in inverse proportion to the rise in temperature is applied to the coil L ₂ . When the temperature rises to 82°C, the current flowing through the coil L ₂ is reduced to zero, and the magnetic field φ ₂ is also reduced to zero. By this, coil L ₁
The magnetic field φ ₁ generated by the coil L 2 and the magnetic field φ ₂ generated by the coil L ₂
are synthesized, and the resultant magnetic field X' changes within the range of angle θ ₁ as shown in Figure 2, and the pointer points to 0° when the temperature is below 50°C, as shown in Figure 4a, and 50°.
When the temperature exceeds ℃, the pointing angle increases, and when it reaches 82℃, it will point at 45℃.

In addition, in the predetermined temperature range between the first range of low temperature range of 82°C or lower and the second range of high temperature range of 110°C or higher, that is, the range of 82°C to 110°C,
Neither the low-temperature operating circuit 3 nor the high-temperature operating circuit 4 is activated, and only a constant magnetic field φ ₁ (FIG. 2) by the bias circuit 2 is generated. Therefore, 82℃ to 110℃
In the temperature range of 0.degree. C., the pointer is caused to point at 45.degree. by means of this magnetic field _.phi.1 , as shown in FIG. 4a.

Further, in the second high temperature range of 110° C. or higher, the first operating circuit, the low temperature operating circuit 3, does not operate, and only the second operating circuit, the high temperature operating circuit 4, operates. As the temperature gradually rises from 110°C, the high-temperature operation circuit 4 supplies a current that gradually increases from zero to coil L ₃ according to the input electrical signal.
The magnetic field φ ₃ (Fig. 2), which gradually increases in proportion to the rise in temperature, is applied to the coil L ₃ to excite the coil L 3 .
Generate to L ₃ . By this, coil L ₁
The magnetic field φ ₁ generated by the coil L 3 and the magnetic field φ ₃ generated by the coil L ₃
are synthesized, and the resultant magnetic field Y' changes within the range of angle θ ₂ as shown in Figure 2, and the pointer pointing at 45° at 110°C has a temperature change as shown in Figure 4a.
As the temperature rises above 110°C, it begins to point to an angle of 45° or more. When the temperature reaches 121 _℃ , _the pointer moves to
The current applied to the coil L ₃ by the high temperature operating circuit 4 is set so as to point at an angle of 76° as shown in FIG.

As mentioned above, the guidelines indicate that in the first range of low temperatures,
In the range of angle θ ₁ from 0° to 45°, in the second range of high temperature range, in the range of angle θ ₂ of 45° to 90°, and between the low temperature range and high temperature range, swinging to an angle of 45°, The characteristics shown in FIG. 4a are obtained.

Figure 3 shows a specific example of the circuit shown in the block diagram in Figure 1. In the figure, a diode D, a resistor
R ₁ , capacitor C ₁ , Zener diode ZD ₁ and transistor Q ₁ constitute a constant voltage circuit 1 and supply a constant voltage. The resistor _R2 constitutes a bias circuit 2 that supplies a constant current to the coil _L1 . resistance
R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , transistor Q ₂ , and operating amplifier OP ₁ constitute a low-temperature operating circuit 3, and the operating amplifier
In OP ₁ , when the voltage applied to one end of resistor R ₃ decreases as the detected temperature rises, its output voltage also decreases, and the output voltage becomes 0 at an input voltage below a predetermined value.
It works as follows. The output voltage of this working amplifier OP ₁ is applied to the base of transistor Q ₂ ,
The current flowing through the coil L ₂ is changed by controlling the conduction of the transistor Q ₂ .

Resistance R ₃ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , transistor
Q ₃ , the operating amplifier OP ₂ constitutes a high temperature operating circuit 4,
The operational amplifier OP ₂ operates to output a voltage that increases in inverse proportion to the input voltage when the voltage applied to one end of the resistor R ₁₀ drops below a predetermined value.
The output voltage of this working amplifier OP ₂ is the transistor
It is applied to the base of Q ₃ to control the conduction of transistor Q ₃ and change the current flowing through coil L ₃ .

The resistor R ₁₂ forms an input circuit that converts the change in the value of the resistor R _S into a voltage by means of a voltage divider formed with the negative temperature-sensitive resistor R _S , and the output voltage of the input circuit decreases as the temperature increases. do. A capacitor C ₂ connected between the connection point of resistors R ₁₂ and R _S and ground integrates the output voltage of the input circuit.

Note that gasoline cars and diesel cars have different temperature-scale characteristics, as shown in Figure 4 a and b, respectively. In such cases, this can be dealt with by changing the value of resistor _R8 . Can be done.

Further, by setting the resistors R ₆ and R ₁₁ as variable resistors, the degree of amplification can be changed by adjusting them, and the slope of the temperature-scale characteristic can be adjusted.

〔Effect of the invention〕

As explained above, since instructions are given by combining the magnetic fields generated by the first to third coils, which are each excited independently, adjustments can be made to improve precision in addition to changing the indication range and inclination. The effect is that it is extremely easy to perform.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic circuit configuration of the present invention, FIG. 2 is a vector diagram explaining the operation of the circuit shown in FIG. 1, FIG. 3 is a circuit diagram showing a specific example of the circuit shown in FIG. The figure is a graph showing an example of the operating characteristics of the rotation shown in Fig. 3, Fig. 5 is a graph showing an example of the characteristics required of an indicating instrument, and Fig. 6 is a conventional example for realizing the characteristics shown in Fig. 5. 7 is a perspective view of a main part of an indicating instrument operated by the circuit of FIG. 6, and FIG. 8 is a vector diagram for explaining the operation of the circuit of FIG. 6. L ₁ ~ L ₃ ... Coil, 3 ... Low temperature operation circuit, 4
...High temperature operating circuit.

Claims (1)

[Claims] 1. A permanent magnet is disposed within a plurality of coils wound in a manner that crosses each other, and the permanent magnet is rotated by an electric signal corresponding to the output of a sensor supplied to the coil. A cross-coil type indicating instrument designed to indicate a value corresponding to a physical quantity detected by a sensor, the first one being excited to constantly generate a constant magnetic field.
a coil, second and third coils wound so as to generate magnetic fields in mutually opposite directions that intersect with the magnetic field generated by the first coil, and a size corresponding to the physical quantity detected by the sensor. first and second actuating circuits that input an electric signal and operate in first and second ranges, respectively, of the magnitude of the electric signal that do not overlap with each other, the first actuating circuit energizing the second coil in response to an input electrical signal having a magnitude in the range of , to generate a magnetic field having a magnitude inversely proportional to the input electrical signal; A crossed coil type indicator, characterized in that the third coil is excited in response to an input electric signal to generate a magnetic field whose magnitude is proportional to the input electric signal.