JPH07111441B2 - Drive for a cross-coil analog indicating instrument - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross-coil type analog indicator, and more particularly to a driving device suitable for driving the analog indicator.

[0002]

2. Description of the Related Art Conventionally, in a drive device of this type, pulse signals are sequentially generated at a frequency proportional to the vehicle speed, as shown in, for example, Japanese Patent Application Laid-Open No. 2-222840, and these pulse signals are generated. , Converting to an analog voltage proportional to the frequency of each of these pulse signals, in accordance with this analog voltage, each drive circuit causes a current to flow into each of the pair of crossing coils of the crossing coil type analog indicating instrument to generate an electromagnetic force from each crossing coil. There is one in which the vehicle speed is indicated by a pointer at a deflection angle corresponding to a combined value of these electromagnetic forces.

[0003]

By the way, in such a configuration, when each of the above-mentioned drive circuits controls the inflow current to each cross coil according to the analog voltage, an operational amplifier is used as an input stage element. Each is adopted. However, in such a case, the output of the operational amplifier is disturbed in phase by disturbance during the operation of each drive circuit, and as a result, an error may be included in the indication of the pointer. On the other hand, it may be possible to connect feedback capacitors between each operational amplifier and the external output terminal of each drive circuit for phase compensation. While only, in this case, the electromagnetic wave as a disturbance enters the respective cross coil, this intrusion electromagnetic wave is made to function as the respective through-capacitors each feedback capacitor, as a result, constituting the subsequent elements of the operational amplifier in each driving circuit However, there is a problem in that the transistor or the like that is operated malfunctions due to the noise caused by the electromagnetic waves penetrating from each feedback capacitor, resulting in a decrease in the pointing accuracy of the pointer. The electromagnetic wave as the disturbance
For example, military radio antennas, television stations
Being transmitted from Tena or amateur radio etc.
is expected. Therefore, in order to deal with the above, the present invention ensures that the electromagnetic coil noise expected to occur due to the intrusion of electromagnetic waves is ensured in the driving device of the cross coil type analog indicating instrument while ensuring its original function. It tries to prevent it.

[0004]

In order to solve the above-mentioned problems, in the invention described in claim 1, electromagnetic forces corresponding to analog inputs which are arranged substantially concentrically intersecting each other are applied to respective inflow currents. depending the pair of cross coils occurs, is applied the analog indicating instrument having a pointer which instructs the analog input in the electromagnetic force resultant value receiving and deflection angle in accordance with the combined value of the previous SL Compared to analog input
A pulse signal that sequentially generates a pulse signal at an example frequency
Generating means and the respective pulse signals of these respective pulse signals
Frequency-voltage converted to analog voltage proportional to frequency
Conversion means and each of the inflow currents corresponding to the analog voltage
And a drive means for causing each of them to flow into each of the crossing coils.
This drive means is provided with the respective inflows to the respective crossing coils.
Operationally amplifying the analog voltage so that current flows
And an operational amplifier for each crossing coil.
Between the feedback resistor and the feedback resistor for the operational amplifier.
It is characterized in that the capacitor and the capacitor are connected in series.
The driving device for the crossing coil type analog indicating instrument
Provided .

[0005]

According to the invention described in claim 1, the pulse signal is
Signal generation means pulse at a frequency proportional to the analog input
When signals are generated sequentially, the frequency-voltage conversion means
An analog signal that is proportional to the frequency of each of these pulse signals.
Convert to a voltage. Then, the driving means uses the operational amplification.
Feedback function of feedback capacitor and feedback resistor
According to the analog voltage, each inflow current to each crossing coil
The operational amplification is performed so that the current flows in, and the
Generate an electromagnetic force corresponding to the input
Instructing analog input at the deflection angle corresponding to the combined value of the electromagnetic force.

[0006]

As described above, the feedback circuit for the operational amplifier is
The capacitor and the feedback resistor are connected in series with each other, and
This feedback capacitor and feedback resistor are
Via the crossing coil because it is connected between
Precisely block electromagnetic noise that enters the operational amplifier side
be able to. This is electromagnetic noise due to feedback resistance
Is appropriately attenuated. Therefore, the operation of the drive means
Can be maintained properly regardless of disturbances such as electromagnetic noise.
Order, the correct indication of the finger needle can be secured.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. FIGS. 1 and 2 show an example in which a drive device D according to the present invention is applied to a vehicle cross-coil type analog indicating instrument 10. . The analog indicating instrument 10 has a pair of crossing coils 11 and 12, and these crossing coils 11 and 1 are provided.
The two are wound so as to cross each other in a cross shape. The cross coil 11 generates an electromagnetic force as a vector quantity in the axial direction according to the inflow current, while the cross coil 12
Generates an electromagnetic force as a vector quantity in the axial direction (that is, the direction orthogonal to the axis of the cross coil 11) according to the inflow current. A disk 13 made of a permanent magnet is provided in each of the crossing coils 11 and 12 about its axis 13a.
12 is rotatably instructed so as to be orthogonal to the respective axes of the disc 12. The disc 13 is magnetized to the N pole and the S pole at each outer peripheral portion on one diameter line thereof, and the magnetic pole A predetermined magnetic force in a direction determined by the property is generated by a vector amount. Then, the disk 13 is clockwise (or counterclockwise) shown in FIG. 2 according to the vector sum of the electromagnetic forces from the two crossing coils 11 and 12 under the predetermined magnetic force.
Turn to. The pointer 14 is a disc 13 as shown in FIG.
Is pivotally supported orthogonally to the shaft 13a of the, and the deflection angle S of the pointer 14 changes according to the rotation of the disc 13.

The driving device D has a constant voltage generator 20 as shown in FIGS. 1 and 3, and the constant voltage generator 20 responds to a constant current from a constant current source Ic to supply a direct current ( Each constant voltage Vc1, Vc2 and Vc3 is generated in relation to the DC voltage Vd from (not shown). As shown in FIG. 1, the drive device D includes a vehicle speed sensor 30, a waveform shaper 40 connected to the vehicle speed sensor 30, and a frequency-voltage converter 50 (hereinafter, referred to as F-
V converter 50) and a vehicle speed sensor 30
Detects the actual vehicle speed V of the vehicle and sequentially generates vehicle speed pulses (see FIG. 8A) at a frequency f (Hz) proportional to this. The waveform shaper 40, as shown in FIG.
Both diodes 41, 41, charging / discharging capacitor 42, constant current source Ic, both Zener diodes 43, 43, resistors 44-44, comparator 45, both inverters 46a,
46b and a transistor 47, each vehicle speed pulse (see FIG. 8A) from the vehicle speed sensor 30 is waveform-shaped and sequentially generated as a shaping pulse (see FIGS. 8B and 8C) from the inverter 46a. The FV converter 50 is
As shown in FIG. 4, both OR gates 51 and 51, transistors 52 to 52, resistors 53, 54 and 54, transistors 55 and 55, F-V conversion one-shot capacitor 56, diodes 57 and 57, respectively. Resistance 58, F-V
Conversion output smoothing capacitor 59a, this capacitor 5
Variable resistor 59b for current-voltage conversion connected in parallel to 9a,
And a constant current source Ic to convert each shaping pulse from the waveform shaper 40 into an analog voltage Vf (see FIG. 8D) proportional to each frequency f (Hz), and this analog voltage Vf is converted. It is generated from the common output terminal of the variable resistor 59b and the capacitor 59a. In such a case, capacitor 5
9a smoothes the analog voltage Vf together with the variable resistor 59b.

The reference voltage generator 60 divides the constant voltage Vc1 by the resistors 61 to 67 directly connected to each other and generates the first to sixth reference voltages from the respective common terminals 61a to 66a. In such a case, the first to sixth reference voltages are 0.5
(V), 0.75 (V), 1 (V), 1.25 (V),
This corresponds to 1.5 (V), 1.75 (V) and 2 (V), respectively. Further, the range of the deflection angle S of the pointer 14 is 0 ° to 360
Corresponds to 0 (V) to 2 (V), and 0.5
(V), 1 (V), 1.5 (V) are 90 °, 180 °,
Each corresponds to 270 °. The comparison circuit 70 has a plurality of comparators 71 to 75.
1 compares the analog voltage Vf from the FV converter 50 with the fourth reference voltage from the reference voltage generator 60. Then, when the analog voltage Vf is higher (or lower) than the fourth reference voltage, the comparator 71 generates a comparison signal at high level (or low level). Comparator 72
Compares the analog voltage Vf from the FV converter 50 with the second reference voltage from the reference voltage generator 60. Then, when the analog voltage Vf is higher (or lower) than the second reference voltage, the comparator 72 generates a comparison signal at high level (or low level). The remaining comparators 73, 74, 75 have a hysteresis characteristic, and the comparator 73 compares the analog voltage Vf from the FV converter 50 with the third reference voltage from the reference voltage generator 60. Then, when the analog voltage Vf is lower (or higher) than the third reference voltage, the comparator 73 generates a comparison signal at high level (or low level). The comparator 74 compares the analog voltage Vf from the FV converter 50 with the first reference voltage from the reference voltage generator 60. Then, when the analog voltage Vf is lower (or higher) than the first reference voltage, the comparator 74 generates a comparison signal at high level (or low level). The comparator 75 compares the analog voltage Vf from the FV converter 50 with the fifth reference voltage from the reference voltage generator 60. Then, when the analog voltage Vf is lower (or higher) than the fifth reference voltage, the comparator 75 generates a comparison signal at high level (or low level).

The saw-tooth wave current generator 80 has a pair of analog switches 81a and 81b. The analog switch 81a becomes conductive in response to the high level comparison signal from the comparator 75, and the analog switch 81a It becomes non-conductive in response to the change to low level. On the other hand, the analog switch 81b becomes conductive in response to the high level comparison signal from the comparator 74, and becomes non-conductive in response to the change of the comparison signal to the low level. Therefore, the sawtooth wave current generator 80 includes both analog switches 81a, 81b and F-V.
A sawtooth current I1 (see FIG. 9A) is generated in response to each operation of the converter 50, the reference voltage generator 60, and the comparison circuit 70. In such a case, the current generator 80 outputs the reference voltage generator 60 while the analog switches 81a and 81b are in conduction.
Receives the sixth and third reference voltages from the
In proportion to the rise of the analog voltage Vf from the converter 50, I
The current I1 is instantly decreased to (-I1m) in response to the non-conduction of the analog switch 81b, and the current I1 is increased from (-I1m) to I1m in proportion to the increase of the analog voltage Vf. In response to the non-conduction of the analog switch 81a, the current I1 is instantly decreased again to (-I1m), and I1 is increased to I1 = 0 in proportion to the increase of Vf. The sawtooth wave current generator 90 includes an analog switch 91.
The analog switch 91 is rendered conductive in response to a high level comparison signal from the comparator 73, and rendered non-conductive in response to a change of the comparison signal to a low level. Therefore, the current generator 90 generates a sawtooth wave current I2 (see FIG. 9B) in response to each operation of the analog switch 91, the reference voltage generator 60 and the FV converter 50. In such a case, the current generator 90 receives the first reference voltage from the reference voltage generator 60 and also receives the fifth reference voltage while the analog switch 91 is in the conductive state to receive the current I1 at F.
The analog voltage Vf from the -V converter 50 is increased from (-I2m) to I2m in proportion to the increase, and the current I2 is instantaneously decreased to (-I2m) in response to the non-conduction of the analog switch 91. , The voltage I2 is increased from (-I2m) to I2m in proportion to the analog voltage Vf.

A current-voltage converter 100 (hereinafter referred to as an IV converter 100) receives a current I1 from a current generator 80 and converts this current I1 into a triangular wave voltage V1 (see FIG. 10A).
Reference). On the other hand, the current-voltage converter 110 (hereinafter referred to as the IV converter 110) receives the current I2 from the current generator 90 and converts this current I2 into the triangular wave voltage V2.
(See FIG. 10B). In such a case, each of the voltages V1 and V2 changes in a triangular wave shape as the analog voltage Vf rises. The function generator 120 has both resistors 121 and 122 connected in series with each other.
Reference numeral 122 divides the constant voltage Vc1 from the constant voltage generator 20 to generate a divided voltage. However, this divided voltage is the analog voltage V corresponding to the deflection angle S = 90 ° −Xb = 46 °.
This corresponds to f = V90-xb. Then, the function generator 120
Is generated as a function voltage Vg1 (see the solid line in FIG. 10C) by changing the triangular wave voltage V1 from the IV converter 100 in relation to the divided voltage from the resistors 121 and 122. In such a case, Vg1 has a waveform that bends linearly at Vf = V90-xb and becomes line-symmetrical at Vf = 0.5 and 1. However, in the function generator 120, the base-emitter voltages of the transistors 123 and 124 are respectively VBE1 and VBE2, the resistance value of the resistor 125 is R125, and the divided voltage of both resistors 121 and 122 is VBE.
Assuming A, the current i1 flowing into the resistor 125 via the transistor 123 is specified by the following equation 1.

## EQU1 ## i1 = (1 / R125) .multidot. (V1-VBE1-VA + VBE2) Therefore, the degree of bending of the functional voltage Vg1 on the waveform is specified by the equation 1.

The function generator 130 has resistors 131 and 132 connected in series with each other.
Reference numerals 1 and 132 divide the constant voltage Vc1 from the constant voltage generator 20 to generate it as a divided voltage. However, this divided voltage is
Analog voltage Vf = Vxb corresponding to S = Xb = 44 °
Equivalent to. Then, the function generator 130 is
The triangular wave-shaped voltage V2 from the IV converter 110 is changed in relation to the divided voltage from 31 and 132 to obtain the functional voltage Vg.
2 (see the solid line in FIG. 10D). In this case, Vg2 bends linearly at Vf = Vxb,
When f = 0.5 and 1, they have line symmetry and a waveform. However, in the function generator 130, the base-emitter voltage of each of the transistors 133 and 134, the resistance 13
In relation to the resistance value of 5 and the divided voltage of both resistors 131 and 132, the current flowing into the resistor 135 through the transistor 133 is specified by the equation 1 substantially as in the case of the function generator 120. Therefore, the degree of bending on the waveform of the function voltage Vg2 is similarly specified by Equation 1.

The function generator 140 has resistors 141 and 142 connected in series with each other.
Reference numerals 1 and 142 divide the constant voltage Vc1 from the constant voltage generator 20 to generate a divided voltage. However, this divided voltage corresponds to the corresponding analog voltage Vf = V90-xa at the deflection angle S = 90 ° −Xa = 71.9 °. Then, the function generator 140 changes the function voltage Vg1 from the function generator 120 in relation to the divided voltage from the resistors 141 and 142 to obtain the function voltage Vh1 (see the solid line in FIG. 10E). Occur. In such a case, Vh1 has a waveform that bends linearly at Vf = V90-xa and is line-symmetrical at Vf = 0.5 and 1. However, in the function generator 140, if the base-emitter voltages of the transistors 143 and 144 are VBE3 and VBE4, the resistance value of the resistor 145 is R145, and the divided voltage of the resistors 141 and 142 is VB, The current i2 flowing through the transistor 143 and into the resistor 145 is specified by the following equation 2.

## EQU00002 ## i2 = {(VB-VBE4) / R155} -Is.exp (q.VBE4 / KT) Therefore, the bending degree on the waveform different from Vg1 of the function voltage Vh1 should be specified by this number 2. Becomes

The function generator 150 has resistors 151 and 152 connected in series with each other.
Reference numerals 1 and 152 divide the constant voltage Vc1 from the constant voltage generator 20 to generate it as a divided voltage. However, this divided voltage is the analog voltage Vf corresponding to the deflection angle S = Xa = 18.1 °.
= Vxa. Then, the function generator 150
The function voltage Vg2 from the function generator 130 is changed in relation to the divided voltage from the resistors 151 and 152, and is generated as the function voltage Vh2 (see the solid line in FIG. 10F). In this case, Vh2 linearly bends at Vf = Vxb,
The waveforms have line symmetry at Vf = 0.5 and 1. However, in the function generator 150, the base-emitter voltage of each of the transistors 153 and 154, the resistance 15
The current flowing through the transistor 153 into the resistor 155 in relation to the resistance value of 5 and the divided voltage of both the resistors 151 and 152 is specified by the equation 2 substantially as in the case of the function generator 140. Therefore, Vg2 of the function voltage Vh2
The degree of bending on a waveform different from is to be specified by Equation 2.

As shown in FIGS. 1 and 6, the output direction switch 160 includes a comparator circuit 160a connected to the current generator 80 and the IV converter 100, and the current generator 90 and I-.
The comparison circuit 160b connected to the V converter 110 and the logic circuit 16 connected to each comparison circuit 70, 160a, 160b
0c. The comparison circuit 160a has both resistors 161 and 162 connected in series with each other,
These resistors 161 and 162 divide the constant voltage Vc2 from the constant voltage generator 20 to generate it as a divided voltage. However, this divided voltage corresponds to (Vc2 / 2). Comparator 1
Reference numeral 63 generates a comparison signal at a high level (or low level) when the voltage corresponding to the current I1 from the current generator 120 is low (or high) due to the divided voltage from the resistors 161 and 162. The comparison circuit 160b has two resistors 164 and 165 connected in series with each other, and these two resistors 164 and 165 have a constant voltage V from the constant voltage generator 20.
c2 is divided and generated as a divided voltage. However, this divided voltage corresponds to (Vc2 / 2). Comparator 166
Generates a comparison signal at a high level (or low level) when the voltage corresponding to the current I2 from the current generator 90 is lower (or higher) than the divided voltage from the resistors 165 and 166. The logic circuit 160c includes both comparators 7
NOR gate 167a connected to No. 1 and 163, and NOR gate 167b connected to both comparators 71 and 72
And a NOR gate 167c connected to the comparator 72 and the NOR gate 167a, and an exclusive OR connected to the comparator 166 and the NOR gate 167c.
Gate 167d, this exclusive OR gate 16
7d and a NOR gate 167e connected to the NOR gate 167b. Therefore, the logic circuit 160c is configured so that the comparators 71, 72, 163,
NOR gate 16 according to the level of the comparison signal from 166
7c and 167e generate first and second output direction switching signals, respectively.

Incidentally, the low level and the high level are represented by "0" and "1", respectively, and each comparator 71,
The comparison signals from 72, 73, 74, 75, 163, and 166 are Ca, Cb, Cs1, Cs2, Cs3, and Csin, respectively.
Ccos, and the first output direction switching signal from the NOR gate 167c and the second output direction switching signal from the NOR gate 167e are respectively represented by Dsin and Dcos. Table-1 is established.

[Table 1]

The drive circuit 170 includes a current control circuit 170a connected to the function generator 140 and an output direction switch 160.
And a transistor circuit 170b connected to. The current control circuit 170a includes an operational amplifier 171 and a dual feedback capacitor 1 for the operational amplifier 171.
74a and 174b and both feedback resistors 175a and 175b that form an essential part of the present invention.
71 has its non-inverting input terminal connected to the output terminal of the function generator 140, and has its inverting input terminal connected to the non-ground terminal of the resistor 172 via the external input terminal P1 of the drive circuit 170. ing. Also, this operational amplifier 17
1 is an output terminal of both transistors 173a, 1
It is connected to each base of 73b, and is also connected to the terminal 11a of the crossing coil 11 through the series circuit of the feedback capacitor 174a and the feedback resistor 175a and the external output terminal P2 of the drive circuit 170. Furthermore, this operational amplifier 1
The output terminal 71 is connected to the terminal 11b of the cross coil 11 through the series circuit of the feedback capacitor 174b and the feedback resistor 175b and the external output terminal P3 of the drive circuit 170. However, in this embodiment, the capacitance of each feedback capacitor 174a, 174b is 20 (p
F) to 30 (pF), and each feedback resistor 175a,
The resistance value of 175b is the same as that of each feedback capacitor 174a, 17a.
It is set to 2 (kΩ) in order to prevent the transmitting action of 4b and properly secure the feedback action. Then, this operational amplifier 17
1 is a function generator 1 that changes the terminal voltage of the resistor 172 under the feedback action of the feedback capacitor 174a and the feedback resistor 175a (or the feedback capacitor 174b and the feedback resistor 175b).
A differential amplification effect is exerted to control the base current of the transistor 173a (or the transistor 173b) so as to match the function voltage Vh1 from 40. The transistor 173a exerts a current amplification action according to the base current based on the differential amplification action of the operational amplifier 171, and the constant current source Ic to the transistor 17 of the transistor circuit 170b.
7 controls the current flowing into the base. On the other hand, the transistor 173b exerts a current amplification action in accordance with the base current based on the differential amplification action of the operational amplifier 171, and the constant current source Ic causes the transistor 17 of the transistor circuit 170b to operate.
Controls the current flowing into the base of 9.

The transistor circuit 170b includes both transistors 177 and 179 as well as both transistors 17 and 179.
6, 178, and the transistor 176 is connected at its base to the output terminal of the NOR gate 167c of the output direction changer 160 via the inverter 176a. The collector of the transistor 176 is connected to the direct current power supply to receive the direct current voltage Vd from the direct current power supply. The emitter of the transistor 176 has a feedback resistor 175a and a protection diode 17a.
It is connected to the terminal 11a of the crossing coil 11 through a common terminal with 6b and the external output terminal P2. Therefore, the transistor 176 is provided with the inverter 176a when the first switching output signal from the NOR gate 167c is low level.
When the first switching output signal is at a high level, the inverter 176a becomes non-conductive due to the inverting action of the inverter 176a. The base of the transistor 177 is the emitter of the transistor 173a and the constant current power source I.
The output direction changer 160 is connected to the output terminal of the output direction switch 160 via both inverters 177a and 177a.
It is connected to the output terminal of the R gate 167c. Also,
The collector of the transistor 177 is connected to the emitter of the transistor 176, and the emitter of the transistor 177 is connected to the non-ground terminal of the resistor 172 via the external input terminal P1. Therefore, this transistor 177 is provided in both inverters 177 when the first switching output signal from the NOR gate 167c is at high level.
a and 177a conduct under each inversion action, and allow a current to flow from the constant current source Ic to the resistor 172 based on the current amplification action of the transistor 173a. On the other hand, the transistor 177 is provided with both the inverters 177a and 177a when the first switching output signal from the NOR gate 167c is low level.
Under the respective inversion effects of the above, the current becomes non-conductive, and the flow of the current into the resistor 172 is blocked.

Transistor 178 has at its base:
It is connected to the output terminal of the NOR gate 167c of the output direction switcher 160 via both inverters 178a and 179b, and the collector of this transistor 178 is connected to the same DC power supply to receive the DC voltage Vd from the DC power supply. There is. The emitter of the transistor 178 is connected to the cross coil 11 through the common terminal of the feedback resistor 175b and the protection diode 178b and the external output terminal P3.
Is connected to the terminal 11b. Therefore, the transistor 178 is provided with both the inverters 179b and 17b when the first switching output signal from the NOR gate 167c is at the high level.
8a conducts under each inversion action, while both inverters 179b, 178 are turned on when the first switching output signal is low level.
It becomes non-conductive under each inversion action of a. Transistor 1
79 has its base connected to the emitter of the transistor 173b and the output terminal of the constant current power source Ic, and also has both inverters 179a, 179a and 179b.
Via the NOR gate 167c of the output direction changer 160
Is connected to the output terminal of. The collector of the transistor 179 is connected to the emitter of the transistor 178, and the emitter of the transistor 179 is connected to the non-ground terminal of the resistor 172 via the external input terminal P1. Then, this transistor 17
Reference numeral 9 denotes each inverter 179b, 179a, 17 when the first switching output signal from the NOR gate 167c is at a low level.
9a conducts under each inversion action, and the transistor 173
The constant current source Ic based on the current amplification action of b to the resistor 172
Allows current to flow in. On the other hand, the transistor 179
Are inverters 179b, 179a, 179 when the first switching output signal from the NOR gate 167c is at a high level.
It becomes non-conducting under each inversion action of a and blocks the inflow of current to the resistor 172.

In the drive circuit 170 thus configured, when the first output direction switching signal from the NOR gate 167c is at the low level, the transistor 176 becomes conductive in cooperation with the inverter 176a, and the transistor 179 causes each inverter to operate. 179b, 179a, 179
Conducts in cooperation with a. Therefore, in cooperation with the function generator 140 and the resistor 172 by the operational amplifier 171 according to the feedback action of the feedback capacitor 174a and the feedback resistor 175a as described above, (function voltage Vh1 / resistance 1
A current corresponding to the resistance value of 72) is supplied from the DC power source to the transistor 176, the cross coil 11, and the transistor 1.
It passes through 79 and flows into the resistor 172. On the other hand, when the first output direction switching signal from the NOR gate 167c is at high level, the transistor 177 causes both the inverters 177a and 17a to operate.
The transistor 1 is turned on by cooperation with 7a.
78 becomes conductive by cooperation with both inverters 179b and 178a. Therefore, the feedback capacitor 17 as described above
4b and the feedback resistance of the feedback resistor 175b, in cooperation with the function generator 140 and the resistor 172 by the operational amplifier 171, the current corresponding to (function voltage Vh1 / resistance value of resistor 172) is Power supply from transistor 17
8, through the crossing coil 11 and the transistor 177 and into the resistor 172. This means that the crossing coil 11 generates an electromagnetic force according to the inflow current with a vector amount determined in the inflow direction. In such a case, the terminal voltage V11 between both terminals 11a and 11b of the crossing coil 11 is proportional to the inflow current to the crossing coil 11, and the analog voltage Vf
In relation to, the waveform changes as shown in FIG.

On the other hand, the drive circuit 180 includes the function generator 15
It is composed of a current control circuit 180a connected to 0 and a transistor circuit 180b connected to the output direction switch 160. The current control circuit 180a includes the operational amplifier 1
81 and both feedback capacitors 184a and 184b for this operational amplifier 181, and both feedback resistors 185a and 185b forming the essential part of the present invention. This operational amplifier 181 has its non-inverting input terminal, Function generator 1
50 is connected to the output terminal of the drive circuit 180, and the inverting input terminal thereof is connected to the resistor 18 via the external input terminal P4 of the drive circuit 180.
It is connected to two non-ground terminals. In addition, the operational amplifier 181 has the output terminals of both transistors 183.
a and 183b, and the cross coil 1 through the series circuit of the feedback capacitor 184a and the feedback resistor 185a and the external output terminal P5 of the drive circuit 180.
2 is connected to the terminal 12b. Further, the operational amplifier 181 has a feedback capacitor 18 at its output terminal.
4b and feedback resistor 185b in series circuit and drive circuit 18
Terminal 1 of the crossing coil 12 through the external output terminal P6 of 0
2a. However, in the present embodiment, the capacitance of each feedback capacitor 184a, 184b is the same as the capacitance of each feedback capacitor 174a, 174b,
The resistance values of the feedback resistors 185a and 185b are the same as the resistance values of the feedback resistors 175a and 175b. Therefore, the operational amplifier 181 has a feedback capacitor 184.
a and the feedback resistor 185a (or the feedback capacitor 184b)
And the feedback action of the feedback resistor 185b),
The differential amplifying action is performed to control the base current of the transistor 183a (or the transistor 183b) so that the terminal voltage of the transistor is matched with the function voltage Vh2 from the function generator 150. The transistor 183a is the operational amplifier 1
In accordance with the base current based on the differential amplification action of 81, the current amplification action is exerted, and the constant current source Ic to the transistor circuit 1
The current flowing into the base of the transistor 187 of 80b is controlled. On the other hand, the transistor 183b is connected to the operational amplifier 1
In accordance with the base current based on the differential amplification action of 81, the current amplification action is exerted, and the constant current source Ic to the transistor circuit 1
The current flowing into the base of the transistor 189 of 80b is controlled.

The transistor circuit 180b includes both the transistors 187 and 189, as well as the both transistors 18 and 189.
6 and 188, the transistor 186 has its base connected to the output terminal of the NOR gate 167e of the output direction changer 160 via the inverter 186a. The collector of the transistor 186 is connected to the DC power supply to receive the DC voltage Vd from the DC power supply, and the emitter of the transistor 186 has a feedback resistor 185a and a protection diode 18a.
It is connected to the terminal 12b of the crossing coil 12 through a common terminal with 6b and an external output terminal P5. Therefore, the transistor 186 is provided with the inverter 186a when the second switching output signal from the NOR gate 167e is low level.
When the second switching output signal is at a high level, the inverter 186a becomes non-conducting. The base of the transistor 187 is the emitter of the transistor 183a and the constant current source Ic.
Connected to the output terminal of both inverters 1
NOR of the output direction switch 160 via 87a and 187a
It is connected to the output terminal of the gate 167e. The collector of the transistor 187 is connected to the emitter of the transistor 186, and the emitter of the transistor 187 is connected to the resistor 1 through the external input terminal P4.
It is connected to the non-ground terminal 82. Then, this transistor 187 is connected to the second gate from the NOR gate 167e.
When the switching output signal is at high level, both inverters 187a,
187a conducts under each inversion action, and the transistor 1
The constant current source Ic based on the current amplification action of 83a to the resistor 1
Allow current to flow into 82. On the other hand, transistor 1
When the second switching output signal from the NOR gate 167e is at a low level, the circuit 87 becomes non-conductive under each inverting action of the two inverters 187a and 187a, and blocks the flow of current into the resistor 182.

Transistor 188 has at its base:
It is connected to the output terminal of the NOR gate 167e of the output direction switcher 160 via both inverters 188a and 189b, and the collector of this transistor 188 is connected to the same DC power supply to receive the DC voltage Vd from the DC power supply. There is. The emitter of the transistor 188 is connected to the cross coil 12 through the common terminal of the feedback resistor 185b and the protection diode 188b and the external output terminal P6.
Is connected to the terminal 12a. Therefore, the transistor 188 is provided with both the inverters 189b and 18b when the second switching output signal from the NOR gate 167e is at the high level.
When the second switching output signal is low level, both the inverters 189b and 188 conduct.
It becomes non-conductive under each inversion action of a. Transistor 1
89 is connected at its base to the emitter of the transistor 183b and the output terminal of the constant current source Ic, and is also connected to the output terminal of the NOR gate 167e of the output direction switch 160 via both inverters 189a, 189a and 189b. It is connected. Also, this transistor 1
The collector of 89 is connected to the emitter of the transistor 188, and the emitter of the transistor 189 is connected to the non-ground terminal of the resistor 182 via the external input terminal P4. Then, this transistor 189
Are inverters 189b, 189a, 189 when the second switching output signal from the NOR gate 167e is at low level.
Conducting under each inversion action of a, the transistor 183b
The current is allowed to flow into the resistor 182 from the constant current source Ic based on the current amplification action of On the other hand, the transistor 189
Are inverters 189b, 189a, 189 when the second switching output signal from the NOR gate 167e is at high level.
It becomes non-conducting under each inversion action of a and cuts off the inflow of current to the resistor 182.

In the drive circuit 180 thus constructed, when the second output direction switching signal from the NOR gate 167e is at the low level, the transistor 186 conducts in cooperation with the inverter 186a and the transistor 189 causes each inverter to operate. 189b, 189a, 189
Conducts in cooperation with a. Therefore, in cooperation with the function generator 150 and the resistor 182 by the operational amplifier 181 corresponding to the feedback action of the feedback capacitor 184a and the feedback resistor 185a as described above, ((function voltage Vh2 / resistance 1
A current corresponding to the resistance value of 82 is applied from the DC power source to the transistor 186, the cross coil 12, and the transistor 1.
It passes through 89 and flows into the resistor 182. On the other hand, when the second output direction switching signal from the NOR gate 167e is at the high level, the transistor 187 causes both the inverters 187a and 187a.
The transistor 1 is turned on by cooperation with 7a.
88 becomes conductive by cooperation with both inverters 189b and 188a. Therefore, the feedback capacitor 18 as described above
4b and the feedback resistance of the feedback resistor 185b, in cooperation with the function generator 150 and the resistor 182 by the operational amplifier 181, the current corresponding to (function voltage Vh2 / resistance value of the resistor 182) is Power supply to transistor 18
8, the crossing coil 12, and the transistor 187 to flow into the resistor 182. This means that the cross coil 12 generates an electromagnetic force according to the inflow current in a vector amount determined in the inflow direction. In such a case, the terminal voltage V12 between both terminals 12a and 12b of the crossing coil 12 is proportional to the inflow current to the crossing coil 12, and the analog voltage Vf
In relation to, the waveform changes as shown in FIG. In this embodiment, the drive unit D (excluding the vehicle speed sensor 30, the capacitors 42, 56 and 59a, the variable resistor 59b and the resistors 172 and 182) is formed by a semiconductor integrated circuit IC. Therefore, each external input terminal P1, P4 and each external output terminal P2, P3, P5, P6 constitutes a connection pin to the external circuit of the semiconductor integrated circuit IC.

In the present embodiment configured as described above,
When the vehicle is running, the frequency of each shaping pulse generated by the waveform shaper 40 in cooperation with the vehicle speed sensor 30 is converted into an analog voltage Vf by the FV converter 50. In this case, if the vehicle speed V increases from V = 0 (Km / h) to V = 300 (Km / h), the analog voltage V
It is assumed that f changes from Vf = 0 (V) to Vf = 2 (V). Then, each of the current generators 80 and 90 cooperates with the reference voltage generator 60 and the comparison circuit 70 to respond to the change of the analog voltage Vf.
1 and I2 (see FIGS. 9A and 9B) are generated. Then,
The IV converters 100 and 110 are the current generators 80 and 90, respectively.
Currents I1 and I2 from the triangular wave voltages V1 and V2 (see FIG. 10).
(See (A) and (B)), and each function generator 1
20 and 130 generate function voltages Vg1 and Vg2 (see FIGS. 10C and 10D) according to the triangular wave voltages V1 and V2, respectively, and the function generators 140 and 150 generate function voltages Vg.
1, the function voltages Vh1 and Vh2 according to Vg2 (FIG. 10E)
(See (F)) respectively, and output direction switch 160
In cooperation with the comparison circuit 70, each current generator 80, 90
The first and second output direction switching signals are selectively generated in response to the respective voltages corresponding to the respective currents I1 and I2 from.

Therefore, in the drive circuit 170, when the first output direction switching signal from the output direction switching unit 160 is at the low level, both transistors 176 and 179 turn off when both transistors 177 and 178 are non-conductive. Conduct.
Therefore, the feedback capacitor 174a and the feedback resistor 175
Under the cooperation of the function generator 140 and the resistor 172 by the operational amplifier 171 according to the feedback action of a, a current corresponding to (function voltage Vh1 / resistance value of resistor 172) is generated from the DC power source to the transistor 176. , Passes through the cross coil 11 and the transistor 179 and flows into the resistor 172. on the other hand,
When the first output direction switching signal from the output direction switcher 60 is at a high level, both transistors 177 and 178 become conductive while both transistors 176 and 179 are non-conductive.
Therefore, the feedback capacitor 174b and the feedback resistor 175
In cooperation with the function generator 140 and the resistor 172 by the operational amplifier 171 according to the feedback action of b, a current corresponding to (function voltage Vh1 / resistance value of the resistor 172) is supplied from the DC power source to the transistor 178. , Through the crossing coil 11 and the transistor 177 and into the resistor 172. on the other hand,
In the drive circuit 180, when the second output direction switching signal from the output direction switching unit 160 is at low level, both transistors 186 and 189 are connected to both transistors 187 and 18.
Conducting under the non-conduction of 8. Therefore, the function generator 150 and the resistor 182 by the operational amplifier 181 corresponding to the feedback action of the feedback capacitor 184a and the feedback resistor 185a.
A current corresponding to (function voltage Vh2 / resistance value of the resistor 182) flows into the resistor 182 from the DC power supply through the transistor 186, the crossing coil 12, and the transistor 189 in cooperation with. On the other hand, when the second output direction switching signal from the output direction switch 160 is at the high level, both transistors 187 and 188 are connected to both transistors 186 and 18.
Conducting under non-conduction of 9. Therefore, the function generator 150 and the resistor 182 by the operational amplifier 181 corresponding to the feedback action of the feedback capacitor 184b and the feedback resistor 185b.
A current corresponding to (function voltage Vh2 / resistance value of the resistor 182) flows into the resistor 182 from the DC power source through the transistor 188, the crossing coil 12, and the transistor 187 in cooperation with. This means that both crossed coils 1
This means that the terminal voltages V11 and V12 of 1 and 12 change in a waveform as shown in FIGS. 11A and 11B according to the analog voltage Vf.

In other words, the analog voltage Vf is 0 (V).
In the process of changing from 1 to 2 (V), each current I1,
I2 changes in phase by 90 ° (corresponding to Vf = 0.5 (V)) to each other and changes into a sawtooth wave shape as shown in FIGS. 9 (A) and 9 (B), and the respective voltages V1 and V2 are different from each other. The function voltage Vg1 changes in a triangular wave shape with a phase difference of 90 °, and
As shown in 0 (C), the voltage V1 is changed so that the apex angle of the waveform of the voltage V1 is increased with V90-xb ≤ Vf ≤ (0.5 + V90-xb) with Vf = 0.5 (V) as the center. Centered around Vf = 1.5 (V) and (1 + V90-xb) ≦ V
At f ≦ (1.5 + V90−xb), the voltage V1 is changed so as to increase the apex angle of the waveform of the voltage V1. On the other hand, the function voltage Vg2 is 0 ≦ as shown in FIG. Vf ≦
The voltage V2 is changed so that the apex angle of the waveform of the voltage V2 at Vxb is increased, and Vf = 1 (V) is set as the center (0.5+
Vxb) ≦ Vf ≦ (1 + Vxb), the voltage V2 is changed so as to increase the apex angle of the waveform of the voltage V2, and (1.
5 + Vxb) ≦ Vf ≦ 2 (V), the voltage V2 is changed so as to increase the apex angle of the waveform of the voltage V2. Further, the function voltage Vh1 is V2 as shown in FIG. 10 (E).
Centered at f = 0.5 (V) V90-xa ≦ Vf ≦ (0.5
+ V90-xa), the function voltage Vg1 is changed so that the waveform of the function voltage Vg1 is almost flat, and Vf = 1.5.
Centering on (V), (1 + V90-xa) ≦ Vf ≦ (0.5+
V90-xa) is formed by changing the function voltage Vg1 so that the waveform of the function voltage Vg1 is substantially flat, while the function voltage Vh2 is 0 ≦ Vf ≦ Vx as shown in FIG.
a, (1-Vxa) ≦ Vf ≦ (1 + Vxa), and (2
-Vxa) ≤ Vf ≤ 2 (V) in each range, the functional voltage Vg2
Is formed by changing the function voltage Vg2 so as to make the waveform of V.sub.2 substantially flat. Therefore, the terminal voltage V11 of the crossing coil 11
Shows a pseudo sine waveform as shown in FIG. 11 (A), while the terminal voltage V12 of the crossing coil 12 has a pseudo cosine waveform as shown in FIG. 11 (B). In such a case, the terminal voltages V11 and V12 change gently due to the above-described analog circuit configuration.

Therefore, the respective terminal voltages V11, V as described above
The pointer 14 swings in accordance with the change in the vehicle speed V in association with each electromagnetic force generated in each of the crossing coils 11 and 12 in accordance with 12 and as a result, it is possible to promote the elimination of discomfort with respect to the degree of swing of the pointer 14. . Further, as described above, in the drive circuit 170, the feedback resistor 175a is connected in series between the feedback capacitor 174a and the external input terminal P2, and the feedback resistor 175b is connected between the feedback capacitor 174b and the external input terminal P3. On the other hand, in the drive circuit 180, the feedback resistor 185a is connected in series between the feedback capacitor 184a and the external input terminal P5, and the feedback resistor 185b is connected in series between the feedback capacitor 184b and the external input terminal P6. I tried to connect. Therefore, as the electromagnetic waves as a disturbance enter the crossing coils 11 and 12, these invading electromagnetic waves are transmitted to the external input terminals P2 and P3, respectively.
Feedback resistors 175a and 175 are respectively provided via P5 and P6.
b, 185a, 185b as electromagnetic noises, the feedback capacitors 174a, 174b, 184a, 1
Even if it invades 84b, each feedback resistor 175
a, 175b, 185a, 185b, based on their respective resistance values, the feedback capacitors 175a, 175b, 185
a) and 185b, the invading electromagnetic wave noises are appropriately attenuated. Therefore, each feedback capacitor 175a, 175
b, 185a, 185b through the respective transistors 173
a, 173b, 183a, 183b do not enter electromagnetic noise, and as a result, each current control circuit 170
a and 180a, the current control action of each transistor 173
It is possible to always ensure proper operation without causing a malfunction due to electromagnetic wave noise of a, 173b, 183a, and 183b.

Incidentally, the feedback resistors 175a and 175 are provided.
b, 185a and 285b are connected to the drive circuits 170 and 180, respectively.
100 (V /
When the effect as an electromagnetic wave when the high frequency electromagnetic field of m) was applied to the device of the present invention was examined, the results shown in FIG. 12 were obtained. However, in FIG. 12, the broken line in the drawing shows a graph when the feedback resistors are not adopted, and the solid line in the drawing shows a case where the feedback resistors are adopted. According to this, the input frequency of the high frequency electromagnetic field is 150 (MHz)
When the feedback resistance is not adopted in the range of 180 to 180 (MHz), the indicated deflection angle of the pointer 14 (deflection angle)
While S) is greatly reduced, it is recognized that when the above feedback resistors are adopted, the indicated deflection angle of the pointer 14 is hardly reduced. This means that the influence of electromagnetic noise can be greatly reduced by adopting the feedback resistors.

In implementing the present invention, the vehicle speed V
However, the present invention may be applied to a driving device for a cross-coil type analog indicating instrument for indicating various analog inputs. Further, in the practice of the present invention, the present invention is applied to create pseudo sine waves and pseudo cosine waves from, for example, triangular waves or trapezoidal waves, instead of creating pseudo sine waves and pseudo cosine waves from sawtooth wave currents. You may carry out. In implementing the present invention, each feedback capacitor 174a, 174b, 184
a, 184b capacitance and each feedback resistor 175a, 17
The resistance values of 5b, 185a, and 185b are, if necessary,
You may change suitably and may implement. Further, in the above-described embodiment, the drive circuits 170 and 180 each have the bridge circuit structure. However, when such a bridge circuit structure is not used, the output direction changer 160 is omitted. Good.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram of a cross-coil type analog indicating instrument.

3 is a detailed circuit diagram of the constant voltage generator of FIG.

FIG. 4 is a detailed circuit diagram of the waveform shaper and FV converter of FIG.

5 is a detailed circuit diagram of the reference voltage generator, the comparison circuit, and both current generators of FIG. 1. FIG.

FIG. 6 is a detailed circuit diagram of both IV converters, function generators, and output direction changers of FIG.

7 is a detailed circuit diagram of both drive circuits of FIG.

FIG. 8 is an output waveform diagram of the waveform shaper and the FV converter of FIG.

FIG. 9 is an output waveform diagram of each current generator of FIG. 1.

10 is an output waveform diagram of each IV converter and each function generator of FIG. 1. FIG.

11 is a terminal voltage waveform diagram of each cross coil of FIG. 1. FIG.

FIG. 12 is a graph showing a relationship between an indicated deflection angle of a pointer and an input frequency of a high frequency electromagnetic wave.

[Explanation of symbols]

10 ... Analog indicating instrument, 11, 12 ... Crossing coil, 1
4 ... pointer, 30 ... vehicle speed sensor, 50 ... FV converter, 6
0 ... Reference voltage generator, 70 ... Comparison circuit, 80, 90 ... Current generator, 100, 110 ... IV converter, 120-1
50 ... Function generator, 160 ... Output direction changer, 170,
180 ... Driving circuit, 171, 181, ... Operational amplifier, 17
4a, 174b, 184a, 184b ... Feedback capacitors, 175a, 175b, 185a, 185b ... Feedback resistors.

Claims (1)

[Claims] 1. A pair of crossing coils arranged substantially concentrically and intersecting each other to generate respective electromagnetic forces corresponding to analog inputs according to respective inflow currents, and a combined value of the respective electromagnetic forces. Applied to an analog indicating instrument having a pointer for indicating the analog input at a deflection angle according to a combined value, pulse signal generating means for sequentially generating pulse signals at a frequency proportional to the analog input, and frequency converting each pulse signal into an analog voltage proportional to the frequency of the pulse signals - voltage converting means and the intersections of the respective inflow current corresponding prior Symbol analog voltage
Drive means for respectively flowing into the coils, and the drive means supplies the inflow currents to the cross coils.
Calculation to amplify the analog voltage so that it will flow in
An operational amplifier, and the operational amplifier and each of the crossing coils
In between, a feedback resistor and a feedback capacitor for the operational amplifier are provided.
Drive for the cross coil type analog indicating instrument, characterized that you and capacitors are connected in series with each other.