JP2003161637A - Temperature compensating circuit of detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately correct the temperature of a detecting coil by detecting a value of temperature resistance of the coil and obtaining temperature data. <P>SOLUTION: Switches 22, 24 which are arranged in parallel connection to capacitors C1, C2 making up an electromagnetic circuit, are controlled so as to be turned on for a constant period by a timer 35, and thereby the capacitors C1, C2 short-circuit. A signal of the DC component flows through a resistor and the detecting coil, and then a DC voltage component is detected from a potential dividing ratio of the coils 14, 15 to resistors R1, R2. A value of coil temperature corresponding to the DC voltage component is searched from a temperature memory table, the amount of phase shift of detected pulse signals is corrected by the correction data based of the value of coil temperature, and therefore the temperature of the detecting coil is accurately corrected. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature compensating circuit of a detecting device for detecting a change in a physical quantity such as a relative rotation angle or a torque quantity by detecting a change in impedance of a detecting coil.

[0002]

2. Description of the Related Art A conventional detection coil has a hollow cylindrical case 1 as shown in a sectional view of FIG.
The core 1 has cores 12 and 13 made of an insulating magnetic material and exciting coils 14 and 15 to which an alternating current is applied. Inside the cylinder of the case 11, two magnetic material rotors (not shown) are arranged with a predetermined gap. An apparatus using this detection coil is disclosed in, for example, Japanese Patent Laid-Open No. 2001-2001.
There is known a relative rotation angle detection device for detecting torque acting on a steering shaft of an automobile as described in Japanese Patent Publication No. 99680.

In this detector, the cores 12 and 13 are
And the two magnetic material rotors and the exciting coils 14 and 15 constitute a magnetic circuit. By measuring the impedance change of the exciting coils 14 and 15 caused by the fluctuation of the eddy current induced in these members, The relative rotation angle of the rotor was detected. Further, a signal processing circuit that detects a change in impedance from the exciting coils 14 and 15 and performs signal processing, an A / D converter, and the like are arranged on the printed board 16 attached on the outer periphery of the case 11.

In such a detection device, a change in the temperature characteristic of the coil greatly affects the detection accuracy of the device. Therefore, in the conventional detection device, this printed circuit board 1
A temperature sensor and a table for a temperature correction memory are arranged on the position 6, and the relative rotation angle is corrected based on the temperature information detected by the temperature sensor.

[0005]

However, in this conventional example, since the coil and the printed circuit board are installed at different positions, the temperature sensor cannot directly detect the actual temperature change of the coil, and the temperature of the coil cannot be detected. If the temperature near the substrate is different from the temperature detected by the temperature sensor, the temperature cannot be accurately corrected.

Further, in this conventional example, a temperature sensor is used, and since such a temperature sensor is generally expensive, there is a problem that the manufacturing cost of the detection device becomes high.

The present invention has been made in view of the above-mentioned problems, and the temperature compensation of the detection device can be accurately performed by obtaining the temperature data by obtaining the temperature resistance value of the coil. The purpose is to provide a circuit.

[0008]

In order to achieve the above object, according to the present invention, a temperature compensating circuit of a detecting device for temperature compensating a detecting coil for detecting a change in impedance caused in a coil by a change in a certain physical quantity, At least one detection coil for detecting a change in the impedance; a supply unit for supplying a DC component signal to the detection coil; a detection unit for detecting the DC component based on a voltage division ratio between the coil and a resistor; Storage means for storing the relationship between the coil temperature and the coil temperature, search means for searching the storage means for a coil temperature corresponding to the detected DC component, and impedance detected by the detection coil according to the searched coil temperature. A temperature compensating circuit for a detecting device is provided, which comprises: a correcting means for correcting a change.

According to the present invention, a DC component signal is supplied to a detection coil for detecting a change in impedance generated in the coil due to a change in a certain physical quantity, and the DC component signal is converted into a voltage value by a voltage division ratio of the coil and the resistance. By detecting the temperature resistance value of the coil and obtaining temperature data by correcting the impedance change by the coil temperature corresponding to this DC component, the temperature of the detection coil can be accurately corrected without using a temperature sensor. To do.

According to a second aspect of the present invention, in the above invention, in the detection device, the detection coil is connected in series with a resistor and a capacitor to form a resonance circuit, and the resonance circuit has a pulse having a DC component. Signal is being supplied,
The supply means includes a switch element connected in parallel with the capacitor, and a switching control unit that turns on the switch element for a certain period of time, and the direct current is applied to the resistor and the detection coil by the on control of the switch element. It is characterized in that a pulse signal having a component is passed.

According to the present invention, the switching element connected in parallel with the capacitor is controlled to be in the ON state for a certain period of time so that the capacitor is short-circuited and a pulse signal having a DC component is supplied to the resistor and the detection coil. , The coil impedance is corrected by the coil temperature corresponding to the voltage division ratio of the DC voltage between the coil and the resistor. That is, the temperature resistance of the coil is obtained and the temperature data is obtained, whereby the temperature of the detection coil is accurately corrected.

According to a third aspect of the present invention, in the above invention, in the detection device, the detection coil is connected in series with a resistor and a capacitor to form a resonance circuit, and a pulse signal is supplied to the resonance circuit. And the supply means is
A first switch element connected in parallel with the capacitor; a current supply section for supplying a current signal of a direct current component to the resistance and the detection coil; and a pulse signal and a current signal from the current supply section for switching the current signal. A second switching element to be supplied to the detection coil; and a switching control section for ON-controlling the first switching element for a certain period of time and switching the second switching element to the current supply section side. One of the switch elements is turned on and the second switch element is switched to the current supply section side to supply a DC component current signal to the resistor and the detection coil.

According to the present invention, the first switch element connected in parallel with the capacitor is controlled to be in the ON state for a certain period of time, thereby short-circuiting the capacitor and removing the current from the current supply unit connected by the second switch element. By supplying a constant current of DC component to the resistance and detection coil for a certain period of time, the DC component signal is detected as a voltage value by the voltage division ratio of the coil and resistance, and the impedance change is corrected by the coil temperature corresponding to this DC component. Then, the temperature resistance of the coil is obtained to obtain temperature data, so that the temperature of the detection coil is accurately corrected.

According to a fourth aspect of the present invention, in the above invention, the detection coil is made of a copper wire having a large temperature coefficient.

According to the present invention, by using the detecting coil made of a copper wire having a large temperature coefficient, the fluctuation of the DC voltage component having a strong correlation with the coil temperature is detected, so that the temperature of the detecting coil is corrected. Do exactly.

According to a fifth aspect of the present invention, in a temperature compensating circuit of a detecting device for temperature compensating a detecting coil for detecting a change in impedance generated in a coil due to a change in a certain physical quantity, at least one of detecting the change in impedance is detected. One detection coil, a dummy coil wound in the same core as the detection coil, a supply means for supplying a signal of a DC component to the dummy coil, and the DC component depending on the voltage division ratio between the dummy coil and the resistor. Detecting means for detecting, a storage means for storing the relationship between the voltage and the coil temperature, a searching means for searching the storage means for a coil temperature corresponding to the detected DC component, and The temperature of the detection device is provided with a correction means for correcting the impedance change detected by the detection coil. Compensation circuit is provided.

According to the present invention, the dummy coil is wound in the same core as the detection coil, and the low voltage of the DC component is supplied from the supply means to the dummy coil, so that the dummy coil and the resistor are separated. The signal of the DC component is detected by the pressure ratio, the impedance change is corrected by the coil temperature corresponding to this DC component, and the temperature resistance value of the coil for detection is calculated to obtain the temperature data. Correct the temperature of the coil.

According to a sixth aspect of the present invention, in the above invention, in the detection device, the dummy coil is connected in series with a resistor, and the supplying means supplies a DC component voltage signal to the resistor and the dummy coil. It is characterized by having a voltage supply unit for supplying.

According to the present invention, the DC voltage component is supplied from the constant voltage source to the resistor and the dummy coil, and the DC voltage component is detected by the voltage value according to the voltage division ratio between the dummy coil and the resistor. The impedance change is corrected by the coil temperature, the temperature resistance value of the coil is obtained, and the temperature data is obtained, whereby the temperature of the detection coil is accurately corrected.

According to a seventh aspect of the present invention, in the above invention, the dummy coil is formed of a copper wire having a large temperature coefficient.

According to the present invention, the dummy coil made of copper wire having a large temperature coefficient is used to detect the fluctuation of the DC voltage component having a strong correlation with the coil temperature, thereby correcting the temperature of the detection coil. Do exactly.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a temperature compensation circuit of a detection device according to the present invention will be described below with reference to the accompanying drawings. In the following drawings, the same components as those in FIG. 5 are designated by the same reference numerals for convenience of explanation.

(Embodiment 1) FIG. 1 is a configuration diagram showing a circuit configuration in Embodiment 1 of a temperature compensation circuit of a detecting device according to the present invention. In the figure, a detection device 20 includes an oscillation circuit 21 that oscillates an oscillation signal, a frequency dividing circuit 22, resistors R1 and R2 to which the frequency-divided oscillation signal is applied, and a detection circuit that is connected in series with the resistor R1. Coil 14 and capacitor C1, detection coil 15 and capacitor C2 connected in series with resistor R2, and capacitors C1 and C1.
2, switches 23 and 24 connected in parallel, pulse signal detection circuits 25 and 26 for detecting pulse signals, DC component detection circuits 27 and 28 for detecting DC components of signals, and pulse signal detection circuits 25 and 26. , DC component detection circuit 27,
A / D converters 29 to 32 that perform analog / digital conversion of signals from 28, a signal processing circuit 33 that performs signal processing of input digital signals, a temperature memory table 34 that stores data for temperature correction, and a switch 23. , 24
Is configured to include a timer 35 for turning on for a certain period of time, output circuits 36 and 37 for outputting signal processed signals, and a power supply circuit 38 for supplying power to each circuit.

For the windings of the detection coils 14 and 15, copper wires having a large temperature coefficient and a stable resistance value with respect to temperature are used. In this embodiment, for example, 4300 ppm /
A copper wire having a characteristic of ℃ is used.

The frequency dividing circuit 22 divides the oscillation signal oscillated from the oscillation circuit 21 to divide it into a specific frequency, for example, 100 kHz.
The pulse signal of z is applied to the detection coil via the resistors R1 and R2. The resistor R1, the detection coil 14 and the capacitor C1 and the resistor R2, the detection coil 15 and the capacitor C2 are connected in parallel to form two resonance circuits, and the other ends of the capacitors C1 and C2 are connected to each other. It is grounded.

When the switches 23 and 24 are off, an AC current is flowing through the detection coils 14 and 15 by applying a pulse signal, and the detection coils 14 and 15 cooperate with a rotor (not shown). It forms a magnetic circuit. The pulse signal detection circuits 25 and 26 detect the amount of phase shift of the pulse signal input from the frequency dividing circuit 22 connected to the detection coils 14 and 15 according to the magnitude of the eddy current generated in the rotor. . That is, the pulse signal detection circuit 2
Reference numerals 5 and 26 detect the phase shift amount of the pulse signals at both ends of the detection coils 14 and 15.

When the switches 23 and 24 are turned on, the resistor R1 and the detecting coil 14 form a voltage dividing circuit, and the resistor R2 and the detecting coil 15 form a voltage dividing circuit. A pulse signal having a DC component will flow through the voltage circuit. That is, when the switches 23 and 24 are turned on, the voltage ratio between the DC component of the voltage difference across the coil and the DC component of the voltage difference across the resistor is proportional to the coil temperature. In this embodiment, the resistors R1 and R2 and the detection coils 14 and 15 are used as voltage dividing resistors to divide the DC component of the excitation voltage signal for detection.

One end of each of the DC component detection circuits 27 and 28 is connected between the resistors R1 and R2 and the detection coils 14 and 15 to detect the voltage of the DC component, and the A / D converters 29 and 30 are connected. It is output to the signal processing circuit 33 via the.

As shown in FIG. 2, it is well known that the DC component of the voltage difference across the coil is proportional to the DC resistance of this coil and is independent of the coil inductance. Since the DC resistance value of this coil is proportional to the coil temperature, the DC component of the voltage difference across the coil has a strong correlation with the coil temperature. The temperature memory table 34 of this embodiment stores data indicating the relationship between the temperature of the coil and the ratio of the DC component of the voltage difference across the coil to the DC component of the voltage difference across the resistor. The correction data of the phase shift amount of the pulse signal with respect to the temperature is stored.

The timer 35 controls the operation of the switches 23 and 24, which are analog switches, at a predetermined time interval. That is, the pulse signal applied to the detection coils 14 and 15 is a signal of 0 to 5V, and includes a DC component of about 2.5V therein. The timer 35, for example, every 1 minute
During 1 msec, the switches 23 and 24 are turned on to eliminate the capacitor component from the two resonance circuits consisting of the resistor, coil and capacitor, and this DC component of the excitation voltage signal is detected by the detection coils 14 and 15 and the resistor. It is detected by R1 and R2.

In such a structure, for example, from the oscillation circuit 21 that performs crystal oscillation, 13 MHz having high stability is provided.
This pulse signal is divided by the frequency dividing circuit 22 to obtain a pulse signal of 100 kHz, and this pulse signal is applied to the two resonance circuits. At this time, when the switches 23 and 24 are turned on under the control of the timer 35, the capacitors C1 and
C2 is short-circuited, resistors R1 and R2 and detection coil 1
A direct current component in the pulse signal flows through 4 and 15, and the direct current component detection circuits 27 and 28 obtain the voltage ratio of the voltage difference between the coil and the resistance as described above, and the signal of this voltage ratio (in the embodiment, The signal is expressed as a voltage value) and is output to the signal processing circuit 33 via the A / D converters 31 and 32.

The signal processing circuit 33 retrieves the temperature data of FIG. 2 from the input voltage value signal to obtain the corresponding coil temperature data, and further shifts the phase of the pulse signal corresponding to this coil temperature data. Find correction data for quantity,
This correction data is stored in the memory inside the circuit.

Since the coil temperature data is updated every minute, the signal processing circuit 33 sequentially rewrites and stores the corresponding correction data. Further, the updating time of the coil temperature data is not limited to the above-mentioned one minute, and when used in a place where the temperature fluctuation is severe, for example,
When the update time is set shorter than this and used in a place where the temperature fluctuation is relatively small, it is possible to set the update time longer than this.

Next, when 1 msec has elapsed, the timer 3
The switches 23 and 24 are turned off by the control of 5. With this switching, the DC components in the pulse signal are cut by the capacitors C1 and C2, only the AC component flows in the detection coils 14 and 15, and the pulse signal detection circuits 25 and 26 generate large eddy currents. The amount of phase shift of the pulse signal corresponding to this is detected and processed as a signal of a voltage value corresponding to this amount of phase shift.

This signal is sent to the A / D converters 29 and 30.
Is input to the signal processing circuit 33 through the signal processing circuit 33. The signal processing circuit 33 corrects the signal of the voltage value corresponding to the phase shift amount based on the correction data stored in the internal memory, and outputs the output circuits 36 and 37. Is output to an external device such as a rotation angle measuring unit. The output circuit 36 outputs phase shift amount data corresponding to the output of the pulse signal detection circuit 25, and the output circuit 37 outputs phase shift amount data corresponding to the output of the pulse signal detection circuit 26. It is output, and the rotation angle measurement unit can determine the relative rotation angle based on these data.

As described above, in this embodiment, the DC component signal corresponding to the coil temperature is detected from the excitation voltage signal to obtain the correction data, and the phase shift of the detected pulse signal is based on the correction data. Since the amount is corrected, the temperature of the detection coil can be accurately corrected and the relative rotation angle can be accurately measured.

Further, in this embodiment, since the DC component corresponding to the coil temperature is detected from the excitation voltage, it is not necessary to provide a temperature sensor or DC power supply as in the conventional case, and the manufacturing cost can be reduced.

(Embodiment 2) FIG. 3 is a block diagram showing the circuit construction of Embodiment 2 of the temperature compensating circuit of the detector according to the present invention. In the following drawings, the same components as those in FIG. 1 are designated by the same reference numerals for convenience of explanation.

In the figure, the difference from FIG. 1 is that a constant current circuit 40 and a switch 41 for switching the connection between the frequency dividing circuit 22 and the constant current circuit 40 are provided, and a switch 35 is used for a constant time constant current. The point is that the circuit is switched to the circuit 40 side and the direct current from the constant current circuit 40 is supplied to the resistors R1 and R2 and the detection coils 14 and 15 instead of the pulse signal supply from the frequency dividing circuit 22. .

In this embodiment, the timer is 1 meter every minute.
While the switches 23 and 24 are controlled to be in the ON state during sec, the switch 41 is connected to the constant current circuit 40 side, and the direct current is supplied from the constant current circuit 40 to the resistors R1 and R2 and the detection coils 14 and 15. .

Also in this embodiment, as in the first embodiment, the DC component detecting circuits 27 and 28 find the voltage ratio of the voltage difference between the coil and the resistor, and the signal of this voltage ratio is sent to the A / D converter 3
It can be output to the signal processing circuit 33 via 1, 32, and the signal processing circuit 33 can obtain the temperature data for correction based on the signal of this voltage ratio.

When the switches 23, 24 and 41 are switched after 1 msec has passed, the detection coil 14,
An alternating current flows through 15, and the signal processing circuit 33 corrects the phase shift amount of the pulse signals input from the pulse signal detection circuits 25 and 26 based on the temperature data.

As described above, in this embodiment, the current signal of the direct current component from the constant current circuit is detected to obtain the correction data, and the phase shift amount of the detected pulse signal is corrected based on the correction data. The temperature of the detection coil can be accurately corrected, and the relative rotation angle can be accurately measured.

Further, in this embodiment, since the current signal of the direct current component which is a constant current is supplied to the detection coil, the accuracy of correction with respect to the temperature fluctuation becomes high, and the relative rotation angle can be measured with high accuracy. .

(Embodiment 3) FIG. 4 is a block diagram showing the circuit construction of Embodiment 3 of the temperature compensating circuit of the detector according to the present invention. In the figure, the difference from the first embodiment is that
While the temperature measurement dummy coils 42 and 43 are wound in the same cores 12 and 13 as the detection coils 14 and 15 (see FIG. 5), a constant voltage is supplied from the constant voltage circuit 44 to the dummy coils 42 and 43. This is the point of application. When winding this coil, two windings may be wound at the same time, and one coil may be set as the detection coil and the other coil may be set as the temperature measurement coil.

Since the cores of the dummy coils 42 and 43 are wound side by side with the detection coils 14 and 15, the temperatures of both coils are considered to be almost the same. In this embodiment, the switches 23 and 24 shown in the first embodiment are omitted by detecting the temperatures of the dummy coils 42 and 43.

In this embodiment, a resistor R connected in series is used.
3, R4 and the dummy coils 42 and 43 are used as voltage dividing resistors to divide the applied constant voltage, and the DC component detection circuits 27 and 28 detect the DC component voltage.

One end of each of the DC component detection circuits 27 and 28 is connected between the resistors R3 and R4 and the dummy coils 42 and 43, and detects the DC voltage component and the A / D converters 29 and 30. It is output to the signal processing circuit 33.

The signal processing circuit 33, like the first embodiment,
It is possible to obtain coil temperature data from the input voltage value signal, obtain correction data for the phase shift amount of the pulse signal corresponding to this coil temperature data, and store this correction data in the memory inside the circuit. it can. Then, the signal processing circuit 33 corrects the detected phase shift amount of the pulse signal based on the correction data.

The present invention is not limited to this embodiment. For example, the number of turns of the dummy coil for coil temperature detection can be smaller than that of the detection coil.
Further, it is possible to make the wire diameter of the dummy coil smaller than the wire diameter of the detection coil to increase the fluctuation of the temperature resistance value.

As described above, in this embodiment, the DC voltage component corresponding to the coil temperature is detected from the dummy coil wound in the same core as the detecting coil at the same time to obtain the correction data, and based on this correction data As described above, since the phase shift amount of the detected pulse signal is corrected, it is possible to obtain the effect that the temperature of the detection coil can be accurately corrected as in the first and second embodiments, and the cost of the analog switch and the timer is high. Since it can be omitted, the manufacturing cost can be reduced. Further, in this embodiment, since the dummy coil is wound only at the same time as the detection coil, the detection device can be manufactured very easily.

In this embodiment, the temperature of the detection coil is not detected, but the temperature of the dummy coil is detected to be simulated as the temperature of the detection coil. Since the coil and the coil are wound next to each other, the temperatures of both coils are considered to be substantially the same, so that the coil temperature detection accuracy is not inferior to that of the first and second embodiments, and highly accurate temperature detection and correction are possible. It is easy to manufacture, inexpensive, and highly practical.

The present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. In these embodiments, the case where the number of detection coils is two has been described, but the present invention is not limited to this, and the same effect can be obtained even when there is one detection coil or a plurality of detection coils. Is possible.

Further, the present invention is not limited to the detection of the torque acting on the steering shaft of the automobile, but if the detection device of a certain physical quantity uses a coil, the temperature compensation circuit of this detection coil is used for temperature compensation for the coil temperature. It is possible to apply.

[0055]

As described above, according to the present invention, a DC component signal is supplied to a detection coil that detects a change in impedance that occurs in a coil due to a change in a certain physical quantity, and a DC voltage is generated by a voltage division ratio between the coil and the resistor. By detecting the voltage component signal and correcting the impedance change detected from the coil by the coil temperature corresponding to the DC voltage component, the temperature resistance value of the coil is obtained to obtain temperature data. By obtaining the temperature data by obtaining the value, the temperature of the detection coil can be accurately corrected.

Further, according to the present invention, the pulse signal from the frequency divider circuit and the current signal from the current supply unit are switched and supplied to the detection coil together with the first switch element connected in parallel to the capacitor of the resonance circuit. And a second switching element for controlling the first switching element to be turned on for a certain period of time, the second switching element is controlled to be switched to the power supply unit side so that the detection coil receives a DC component signal. The temperature resistance value of the coil is supplied by detecting the DC voltage component signal by the voltage division ratio of the coil and the resistance, and correcting the impedance change detected from the coil by the coil temperature corresponding to the DC voltage component. Since the temperature data is obtained, the temperature resistance of the coil is obtained and the temperature data is obtained, whereby the temperature of the detection coil can be accurately corrected.

Further, according to the present invention, the dummy coil is wound in the same core as the detecting coil, and the DC voltage component is applied to the dummy coil so that the DC voltage component is divided by the resistor. The temperature resistance value of the coil is obtained by calculating the temperature resistance value of the coil by detecting the component and correcting the impedance change detected from the coil by the coil temperature corresponding to the DC voltage component. By obtaining the temperature data by using the temperature data, the temperature of the detection coil can be accurately corrected.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a circuit configuration in a first embodiment of a temperature compensation circuit for a detection coil according to the present invention.

FIG. 2 is a diagram showing a relationship between a voltage ratio and a temperature stored in a temperature memory table shown in FIG.

FIG. 3 is a configuration diagram showing a circuit configuration in a second embodiment of a temperature compensation circuit of a detection device according to the present invention.

FIG. 4 is a configuration diagram showing a circuit configuration in a third embodiment of a temperature compensation circuit of a detection device according to the present invention.

FIG. 5 is a cross-sectional view showing a cross section of a conventional detection coil.

[Explanation of symbols]

11 cases 12,13 core 14,15 Detection coil (excitation coil) 16 printed circuit board 20 Detector 21 Oscillation circuit 22 frequency divider 23, 24, 41 switch 25,26 pulse signal detection circuit 27, 28 DC component detection circuit 29-32 converter 33 Signal processing circuit 34 Temperature memory table 35 timer 36,37 output circuit 38 Power supply circuit 40 constant current circuit 42,43 dummy coil 44 constant voltage circuit C1, C2 capacitors R1 to R4 resistance

Continued front page    F term (reference) 2F077 AA13 FF03 FF13 FF31 FF39                       TT04 UU07                 3D033 CA28 CA29

Claims (7)

[Claims] 1. A temperature compensating circuit of a detecting device for temperature compensating a detecting coil for detecting a change in impedance generated in a coil due to a change in a certain physical quantity, and at least one detecting coil for detecting the change in impedance, Supplying means for supplying a DC component signal to the detection coil, detecting means for detecting the DC component based on a voltage division ratio of the coil and resistance, storage means for storing a relationship between voltage and coil temperature, and the detecting means. It is characterized by further comprising: a search unit that searches the storage unit for a coil temperature corresponding to a DC component; and a correction unit that corrects an impedance change detected by the detection coil according to the searched coil temperature. Temperature compensation circuit for detection device. 2. In the detection device, the detection coil is connected in series with a resistor and a capacitor to form a resonance circuit, and a pulse signal having a DC component is supplied to the resonance circuit, and the supply means is provided. Has a switch element connected in parallel to the capacitor, and a switching control unit for ON-controlling the switch element for a certain period of time, and having the DC component in the resistance and the detection coil by ON-controlling the switch element. The temperature compensation circuit of the detection device according to claim 1, wherein a pulse signal is passed. 3. In the detection device, the detection coil is connected in series with a resistor and a capacitor to form a resonance circuit, and a pulse signal is supplied to the resonance circuit, and the supply means includes the capacitor. First connected in parallel to
A switch element, a current supply section for supplying a current signal of a direct current component to the resistor and the detection coil, and a second signal for switching between the pulse signal and the current signal from the current supply section and supplying the current signal to the detection coil. A switch element; and a switching control unit that controls ON of the first switch element for a certain period of time and switches the second switch element to a current supply unit side, and ON control of the first switch element and the switching control unit. 2. The temperature compensating circuit for a detection device according to claim 1, wherein the second switch element is controlled to be switched to the side of the current supply unit to supply a current signal of a direct current component to the resistance and the detection coil. 4. The temperature compensating circuit for a detection device according to claim 1, wherein the detection coil is made of a copper wire having a large temperature coefficient. 5. A temperature compensating circuit of a detecting device for compensating the temperature of a detecting coil for detecting a change in impedance generated in a coil due to a change in a certain physical quantity, and at least one detecting coil for detecting the change in impedance, A dummy coil wound in the same core as the detection coil; a supply means for supplying a DC component signal to the dummy coil; and a detection means for detecting the DC component based on a voltage division ratio between the dummy coil and a resistor. A storage means for storing the relationship between the voltage and the coil temperature; a search means for searching the storage means for a coil temperature corresponding to the detected DC component; and a detection coil detected by the detection coil according to the searched coil temperature. A temperature compensating circuit for a detecting device, comprising: 6. In the detection device, the dummy coil is connected in series with a resistor, and the supply unit has a voltage supply unit that supplies a voltage signal of a direct current component to the resistor and the dummy coil. The temperature compensation circuit of the detection device according to claim 5. 7. The temperature compensating circuit for a detecting device according to claim 5, wherein the dummy coil is made of a copper wire having a large temperature coefficient.