JPH0894672A - Moving magnet-type gauge device - Google Patents

Abstract

PURPOSE: To non-linearly indicate characteristics changing indication values when a power source is turned OFF, by fixing a fixed magnet and a first coil wound around a core, connecting a resistor in series to a sensor and the first coil, connecting a first constant voltage diode in parallel to the first coil and controlling a current flowing in the first coil. CONSTITUTION: An indicator is attached to a rotary shaft of a moving magnet 1. A set core 3 is separated an angle 6 from a fixed magnet 2. While a resistor 8 is connected in series to a circuit wherein a first constant voltage diode 6 is connected in parallel to a first coil 4, a sensor 9 is connected in series to the resistor 8. Moreover, a second coil 5 is connected to the sensor 9 via a circuit wherein a second constant voltage diode 7 is connected in series to the second coil 5. A constant voltage of the diode 6 is set to be lower than a constant voltage of the diode 7. A coil current-controlling means 10 indicates linearly when an output of the sensor is high and non-linearly when the output is smaller than a middle level. When a power source is turned OFF, the controlling means 10 moves the indicator outside an indication range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving magnet type gauge device having a pointer indicating characteristic of a non-linear indicating characteristic.

[0002]

2. Description of the Related Art For example, in a gauge device for displaying a water temperature or a fuel amount of a vehicle, a device for indicating a pointer with a nonlinear instruction is generally used. That is, when the temperature of the engine is low, the output is reduced and the fuel consumption is poor, and when the temperature is high, knocking occurs, the output is reduced, and the fuel consumption is deteriorated.

Therefore, in the water temperature gauge device for indicating the water temperature of the water for cooling the engine, the indication of the low temperature portion and the high temperature portion, which is a temperature bad for the operation of the engine, is accurate, and the middle temperature portion is merely a suitable temperature. A medium temperature stable gauge device is used that shows only

Such a conventional gauge device will be described with reference to FIG. In FIG. 4A, 11 is a moving magnet, 12 is a fixed magnet that gives a constant magnetic field to the moving magnet 11, 13 is a core, and 14 is a coil. Although not shown, a pointer for pointing is attached to the rotating shaft of the moving magnet 11, and the pointer also gives a rotation instruction when the moving magnet 11 rotates.

FIG. 4B shows a circuit for generating a magnetic field in the coil 14, 15 is a constant voltage diode, 16 is a sensor, and 17 to 19 are resistors. When the resistance value R _x of the sensor 16 is high, the voltage across R ₂ is constant voltage diode 1
It becomes higher than the sum of the Zener voltage of 5 and the voltage across the resistor 19, and a current flows through the coil 14 from left to right.

When the resistance value of R _x gradually decreases, the voltage across R _x also decreases, and when the voltage across R _x becomes less than the zener voltage of the zener diode + the voltage across resistor 19, a current flows through coil 14. Will not flow. When the resistance value of R _x further decreases and the voltage across R _x becomes lower than the voltage across resistor 19, a current flows in the coil 14 from the right to the left.

That is, when the resistance value R _x of the sensor 16 is high, a current flows through the coil 14 from the left to the right, which causes a magnetic field φ _Mg of the fixed magnet 12 as shown in FIG. 4 (c). A magnetic field of φ _{CH in} the direction of the right angle, and when R _x gradually decreases and the resistance value decreases, a current flows from the right to the left in the coil 14, and a magnetic field of φ _CC occurs in the direction opposite to φ _CH .

When a magnetic field of φ _CH is generated from the coil 14, it is combined with the constant magnetic field φ _Mg of the fixed magnet 12, and the moving magnet 11 rotates in the direction of the combined magnetic field ((H) in FIG. 4C). . When a magnetic field of φ _CC is generated by the coil 14, the moving magnet 11 rotates in the direction shown in (C) of FIG.

[0009]

However, in the conventional moving magnet type gauge device as described above, when the power source V is turned off, the current does not flow in the coil 14 and the magnetic field is not generated. Therefore, the moving magnet 11
Is attracted by the fixed magnet 12, and the indication of the pointer indicates the position where the resistance value of the sensor 16 corresponds to the middle value.

Therefore, when the power is turned on, if the resistance value of the sensor 16 is medium, the indication of the pointer does not change even if the power is turned on and off. If the gauge device fails, the indication of the pointer does not change. I couldn't judge whether it would change by, and gave me anxiety.

It is an object of the present invention to provide a moving magnet type gauge device which gives a non-linear characteristic indication such that the indication value changes when the power is turned off.

[0012]

Means adopted by the present invention for solving the above-mentioned problems will be described. In a moving magnet type gauge device that rotates a moving magnet 1 in response to an output from a sensor 9 to give a pointer, a fixed magnet 2 that generates a constant magnetic field with respect to the moving magnet 1, and a fixed magnet 2 A first coil 4 wound around a core 3 set at an angle θ; a resistor 8 connected in series to the sensor 9 and the first coil 4;
Coil current control means 10 including a first constant voltage diode 6 connected in parallel to the coil 4 of FIG.

Further, the core 3 is provided with a second coil 5, and the coil current control means 10 is provided with a second constant voltage diode 7 connected in series to the sensor 9 and the second coil 5. To be provided. Further, the constant voltage value of the first constant voltage diode 6 is made lower than the constant voltage value of the second constant voltage diode 7.

[0014]

The fixed magnet 2 generates a constant magnetic field for the moving magnet 1. The first coil 4 is attached to the core 3 placed at a position separated from the fixed magnet 2 by an angle θ.

The coil current control means 10 connects a resistor 8 in series with the sensor 9 and the first coil 4, and
First voltage regulator diode 6 connected in parallel to the coil 4 of
Is connected to control the current flowing through the first coil 4. Further, the second coil 5 is attached to the core 3, and the coil current control means 10 is provided with a circuit in which the sensor 9 and the second constant voltage diode 7 are connected in series to the second coil 5.

The constant voltage value of the first constant voltage diode 6 is set lower than the constant voltage value of the second constant voltage diode 7. As described above, the first coil is fixed to the core installed at the position separated by the angle θ with respect to the fixed magnet, and the resistor is connected in series to the sensor and the first coil. Since the first constant-voltage diode is connected in parallel to control the current flowing through the first coil, the pointer is directed linearly when the sensor output is high and nonlinear when the sensor output is below the middle level. In addition, when the power is off, the pointer indication outside the indication range can be given.

Further, the second coil is provided in the core, and the second constant voltage diode is connected in series with the sensor and in series with the second coil to control the current of the second coil. Even when the sensor output is low, the linear pointer instruction can be given. Further, since the constant voltage value of the first constant voltage diode is set lower than the constant voltage value of the second constant voltage diode, the range corresponding to the difference between the constant voltage values can be instructed by the non-linear pointer.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of an embodiment of the present invention. Figure 1 (A)
In FIG. 1, 1 is a moving magnet, 2 is a fixed magnet, 3 is a core, and 4 and 5 are a first coil and a second coil, respectively.

A pointer (not shown) is attached to the rotating shaft of the moving magnet 1. Further, the core 3 is the fixed magnet 2
And the angle θ are set apart. First coil 4 and second
1B, a resistor 8 is connected in series to a circuit in which a first constant voltage diode 6 is connected in parallel to the first coil 5 as shown in FIG. 9
In addition, the second coil 5 is connected to the sensor 9 through a circuit in which the second constant voltage diode 7 is connected in series.

Further, the constant voltage value of the first constant voltage diode 6 is set to be lower than the constant voltage value of the second constant voltage diode 7. The following description will be made assuming that the sensor 9 is a temperature sensor and has a characteristic that the resistance value R _{x of the} sensor is high when the temperature is low and R _x is low when the temperature is high.

When R _x is high, the current flowing through R _x is small, and I _Rx = I _R = I _L1 = V / (R _L1 + R + R _x ) I _L2 = 0 (1) where I _Rx and R _x are Current flowing through the sensor 9, resistance value,
I _R and R are currents flowing through the resistor 8 and resistance values, I _L1 and R _L1 are currents flowing through the first coil 4, resistance values, and I _L2 is current flowing through the second coil 5.

That is, the voltage across the first coil 4 is lower than the constant voltage value of the first constant voltage diode 6, and the voltage across the series circuit of the first coil 4 and the resistor 8 is the second constant voltage. Since it is lower than the constant voltage value of the voltage diode 7, no current flows through both constant voltage diodes.

When the resistance value R _{x of the} sensor 9 rises as the temperature rises and R _x becomes lower, the voltage across the first coil 4 rises and becomes equal to the constant voltage value V _{Z1 of} the first constant voltage diode 6. They become equal, and thereafter, a current I _L1 = V _Z1 / R _L1 (= I _M (constant value)) (2) flows through the first coil 4.

The resistance R _{x of the} sensor 9 becomes smaller, and the sum of the constant voltage value V _{Z1 of} the first constant voltage diode 6 and the voltage V _R across the resistor 8 becomes the constant voltage value V of the second constant voltage diode 7.
Becomes equal to _Z2, subsequent to the second coil _{5, I Z2 = (V Z1} + V R -V Z2) / R Z1 ... (3) becomes a current flows.

In FIG. 2A, when the current V is turned on and the resistance value of the sensor 9 is high and R _2C , I shown by the equation (1) is given.
_A current I _C corresponding to _L1 flows through the first coil. When the engine is rotated, the temperature rises, the sensor resistance R _x decreases, and R _{x M1} is reached, I corresponding to I _L1 shown in the equation (2) is obtained.
_A current _M flows in the first coil, and then a constant current flows even if R _x becomes smaller.

When the temperature further rises and the sensor resistance R _x becomes R
_When it reaches _xM2 , I _L2 shown by the equation (3) flows. By the current flowing through the first coil 4 and the second coil 5, magnetic fields φ _C1 and φ _C2 as shown in FIG. 2 (B) are generated and combined with the magnetic field φ _Mg emitted by the fixed magnet 2. hand,
Magnetic fields in the directions of C, M, and H are generated corresponding to the magnetic fields of φ _C1 and φ _C2 .

The moving magnet 1 is attracted by the combined magnetic field and rotates so as to match the direction of the combined magnetic field. Therefore, as shown in FIG. 3A, the resistance value R _x of the sensor 9 and the deflection of the pointer are 0 when the power is off, and the resistance value R _x is R _{xC to} R _xM1 and R _{xM2 to} R _xH. Is indicated linearly, and the range from R _{xM1 to} R _xM2 is indicated non-linearly. That is, it becomes a medium temperature stable type temperature gauge.

The characteristics can be changed by changing the constant voltage values of the first constant voltage diode 6 and the second constant voltage diode 7. Further, by removing the second coil 5 and the second constant voltage diode 7, it is possible to obtain a low-temperature linear indicating characteristic as shown in FIG. 3 (B).

[0029]

As described above, according to the present invention, the following effects can be obtained. A first coil is fixed to a core installed at a position separated by an angle θ with respect to a fixed magnet, a resistor is connected in series to the sensor and the first coil, and a first coil is connected in parallel to the first coil. Since the constant voltage diode of is used to control the current flowing through the first coil, the pointer is linearly indicated when the sensor output is high and non-linear when the sensor output is below the middle level, and when the power is off. It is possible to have a pointer instruction outside the instruction range.

Further, since the second coil is provided in the core and the second constant voltage diode is connected in series with the sensor and the second coil to control the current of the second coil, Even when the output is low, the linear pointer can be instructed. Further, since the constant voltage value of the first constant voltage diode is set lower than the constant voltage value of the second constant voltage diode, it is possible to perform the non-linear pointer instruction in the range corresponding to the difference between the constant voltage values.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the embodiment.

FIG. 3 is an operation explanatory diagram of the embodiment.

FIG. 4 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1 Moving Magnet 2 Fixed Magnet 3 Core 4, 5 Coil 6, 7 Constant Voltage Diode 8 Resistor 9 Sensor 10 Coil Current Control Means

Claims (3)

[Claims] 1. A moving magnet type gauge device for rotating a moving magnet according to an output from a sensor to give a pointer instruction, wherein a fixed magnet for generating a constant magnetic field for the moving magnet, and the fixed magnet. A first coil wound around a core set at an angle θ, a resistor connected in series to the sensor and the first coil, and a first coil connected in parallel to the first coil. A moving magnet type gauge device, comprising: a coil current control means composed of a constant voltage diode. 2. A second coil is provided in the core, and the coil current control means is provided with a second constant voltage diode connected in series to the sensor and the second coil. The moving magnet type gauge device according to claim 1, which is characterized in that. 3. The moving magnet type gauge device according to claim 2, wherein the constant voltage value of the first constant voltage diode is set lower than the constant voltage value of the second constant voltage diode.