JPH10253664A - Driving device for cross-coil instruments - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To make it possible to change the sensitivity of a pointer operation to a change in a running speed or an engine speed without replacing an integrated circuit part. SOLUTION: Separately from an electric element 10 relating to an operation of generating a drive pulse signal having a duty ratio according to a pulse interval of the travel pulse from a travel pulse and an operation of supplying the drive pulse signal to a cross coil L. A plurality of supply update periods T ₁ stored in the provided period storage means 30
From through T _4, the single feed update period T ₁ through T ₄ selected by the periodic selection means 20, the period setting unit 10A, is set to the supply update cycle of the drive pulse signal to the cross coil L, the period setting unit 10A The drive pulse signal supplied to the cross coil L is updated to a newly generated drive pulse signal at each of the supply update periods T _{1 to} T ₄ set by the user.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for driving a cross-coil type instrument used as a speedometer or a tachometer of a vehicle.

[0002]

2. Description of the Related Art A vehicle is provided with various instruments for visually confirming a traveling state. Among them, a speedometer for confirming a traveling speed of a vehicle and a speedometer for confirming an engine rotation speed of the vehicle. In the case of an analog type tachometer, a cross coil type instrument is generally used. As a conventional driving device for a cross-coil type instrument, for example, a functional block diagram shown in FIG.
A drive device disclosed in Japanese Patent Application No. 01167 is known.

In this drive device, a running pulse signal whose cycle changes in accordance with the speed of a vehicle and the number of revolutions of an engine is input to a counter circuit 1.
The number of basic clocks input from the oscillation and frequency dividing circuit 2 to the counter circuit 1 during one cycle of the running pulse is counted, and the counted value is converted to digital data by the RO.
The signal is input to a sin function generating circuit 3 composed of M.

The sine function generation circuit 3 outputs sine data of the angle θ corresponding to the value of the digital data from the counter circuit 1 to the sine duty pulse generation circuit 4, and sine (90 ° ± θ) = cos θ (90 ° ± θ) with the phase shifted by 90 ° from the angle θ corresponding to the digital data, that is, cos θ
, That is, the cosine data of the angle θ is output to the cos duty pulse generation circuit 5.

A sine duty pulse generating circuit 4 to which sine data of an angle θ is input from a sine function generating circuit 3
Generates a duty pulse signal of a constant frequency based on the basic clock from the oscillation and frequency dividing circuit 2 and outputs it to the drive circuit 6. Similarly, the cosine data of the angle θ from the sin function generating circuit 3 The input cos duty pulse generating circuit 5 generates a duty pulse signal having a constant frequency based on the basic clock from the oscillation and frequency dividing circuit 2 and outputs the generated duty pulse signal to the drive circuit 7.

Then, the drive circuit 6 applies the first sine data corresponding to the angle θ from the sine function generation circuit 3 between the terminals a ₁ and a _{2 of} the first coil L ₁ constituting the cross coil L. of supplying a pulse current I _1, the drive circuit 7 is arranged to be perpendicular to the first coil L _1, the second coil L ₂ together with the first coil L ₁ constituting the cross coil L Between the terminals b ₁ and b ₂ , a second pulse current I ₂ corresponding to the cosine data of the angle θ from the sine function generation circuit 3 is supplied.

As a result, a composite magnetic field of the magnetic field generated in the first coil L ₁ and the magnetic field generated in the second coil L ₂ is generated in the cross coil L, and the vector direction of the composite magnetic field is And the direction of rotation of the engine, that is, the direction according to the measured amount, and the magnet rotor Mg in the cross coil L is rotated by the synthesized magnetic field, and the pointer (not shown) fixed to the rotation shaft of the magnet rotor Mg. The vector direction of the synthetic magnetic field of the cross coil L is indicated, and the measured amount is displayed in cooperation with a dial (not shown).

In the above-described cross-coil type instrument, when the pulse period of the running pulse changes in accordance with the change in the running speed of the vehicle or the engine speed, the sine data and cosine data from the sin function generating circuit 3 and, consequently, The first and second pulse currents I ₁ and I ₂ from the drive circuits 6 and 7, the combined magnetic field of the cross coil, and the direction indicated by the pointer change accordingly.

In recent years, there has been a tendency to provide various types of vehicles such as a sports type, a saloon type, an outdoor type, etc. so that they can be selected according to the purpose of use and preference. Meters are also sensitive to changes in running speed and engine speed with emphasis on accuracy, and fine-tuned running speed and engine speed with emphasis on legibility so that the pointer does not blur and become difficult to see. The types are divided into those that do not react unnecessarily to fluctuations.

Therefore, in the case of the above-mentioned conventional cross-coil type instrument, for example, the oscillation and frequency dividing circuit 2
By changing the clock cycle of the basic clock input to the n-duty pulse generation circuit 4 and the cos duty pulse generation circuit 5, the duty pulse signal is
By changing the output period, the sensitivity of the pointer operation to a change in the running speed or the engine speed can be changed.

A measure for changing the sensitivity of the pointer operation to a change in the running speed or the engine speed is based on a duty pulse signal generated from a running pulse after the running speed or the engine speed changes. It is determined how long the second pulse currents I ₁ and I ₂ are supplied to the first and second coils L ₁ and L ₂ of the cross coil L after a change in the traveling speed or the engine speed. Anything that can be finally changed is not limited to the above-described change of the clock cycle.

[0012]

However, the driving device as described above has been developed with the recent improvement of semiconductor mounting technology.
In general, each circuit is not a single product but a dedicated integrated circuit together with other circuits.Therefore, the sensitivity of the pointer operation to fluctuations in running speed and engine speed is reduced. In order to make the change, no matter what measures are taken, it is necessary to change the circuit in the integrated circuit.

Therefore, unless the entire circuit constituting the drive device, that is, the integrated circuit itself is replaced, including the circuit which does not require other changes, the response of the pointer operation to the fluctuation of the traveling speed and the engine speed is sensitive. However, there has been a problem that a measure must be taken to prepare a number of integrated circuits for driving the instruments corresponding to the types of the instruments having different sensitivities, which causes a significant increase in cost.

The present invention has been made in view of the above circumstances,
An object of the present invention is to drive a cross-coil of an instrument such as a speedometer or a tachometer by a traveling pulse generated with the traveling of a vehicle, and to increase sensitivity of a pointer operation to a variation in a traveling speed or an engine speed. It is an object of the present invention to provide a driving device for a cross-coil instrument which can be changed without replacing an integrated circuit part.

[0015]

According to the first aspect of the present invention, there is provided a driving apparatus for a cross-coil type instrument which achieves the above object, as shown in a basic configuration diagram of FIG. A drive pulse signal having a duty ratio corresponding to a pulse interval of the travel pulse is generated from the travel pulse, and the drive pulse signal is supplied to the cross coil L while periodically updating the drive pulse signal to the newly generated drive pulse signal. Then, in the drive device of the cross-coil type instrument for driving the magnet rotor Mg by the drive pulse signal, the operation of generating the drive pulse signal from the running pulse and the operation of supplying the drive pulse signal to the cross coil L Are provided separately from the electric element 10 relating to the driving pulse signal supply update period T _{1 to} T ₁ to the cross coil L.
₄ and period storage means 30 is more stored, the plurality stored in the period storage unit 30 supplies the update period T ₁
A period selection means 20 from through T ₄ to select a single feed update period T ₁ through T _4, the supply update cycle of the drive pulse signal to the cross coil L, the period storage unit 30
Among the plurality of the supply update period T ₁ through T _4, which is stored in, and a period setting section 10A is set to supply the update period T ₁ through T _4, which is selected by the period selection unit 20, the period setting The drive pulse signal to be supplied to the cross coil L is updated to a newly generated drive pulse signal at each of the supply update periods T _{1 to} T ₄ set by the means 10A. .

In the driving apparatus for a cross-coil meter according to the present invention, the period storage means 30 is constituted by a rewritable nonvolatile memory.

Further, in the driving device for a cross-coil type meter according to the present invention, the electric element 10 is constituted by a dedicated integrated circuit, and the period storage means 3 is provided.
0 is constituted by an external storage element connected to the integrated circuit and exchangeable independently of the integrated circuit.

According to the driving apparatus for a cross-coil type instrument of the present invention described in claim 1, even if the response of the pointer operation to the fluctuation of the running speed or the engine speed is different,
The supply update periods T _{1 to} T ₄ according to the sensitivity are stored in a plurality of supply update periods T ₁ to T ₄ stored in the period storage unit 30.
May be selected by the period selection unit 20 from T _4, therefore, the operation of generating the drive pulse signal from the running pulse, and, without replacing the electric element according to the supply operation for the cross coil of the drive pulse signal, sensitive reaction It is possible to cope with a plurality of types of instruments of different types with a single drive device.

According to the driving apparatus for a cross-coil instrument of the present invention, the contents of the plurality of supply update periods T _{1 to} T ₄ stored in the period storage means 30 are stored in the nonvolatile memory. By changing by rewriting, it is possible to easily change the group of compatible instrument types from one type group to another type group without exchanging the electric element 10, and to improve versatility.

Further, according to the driving apparatus for a cross-coil type instrument of the present invention described in claim 3, the period storage means 30
The contents of a plurality of supply update periods T _{1 to} T ₄ stored in
By changing by replacing the external storage element, it is possible to easily change the group of the types of instruments that can be supported from one type group to another type group without replacing the integrated circuit integrated electric element 10, thereby improving versatility. It is possible to increase.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a driving device for a cross-coil instrument according to the present invention.

FIG. 2 shows a cross-coil type instrument according to the present invention.
Vehicle speed according to one embodiment of the present invention employing a driving device
It is a block diagram showing the electrical configuration of the drive device of the degree meter,
Driving device for a vehicle speedometer of the present embodiment (hereinafter referred to as driving device
Are abbreviated to the first and second orthogonal to each other as in FIG.
And the second coil L₁, L_TwoCross carp composed of
The first L and the second L corresponding to the pulse period of the running pulse
Pulse current I₁, I _TwoRespectively.

The driving device of this embodiment is a one-chip microcomputer (hereinafter abbreviated as CPU).
10, a dip switch 20, and a non-volatile memory (hereinafter abbreviated as NVM) 30.

The CPU 10 (corresponding to an electric element and an integrated circuit) has a built-in RAM 10a and a ROM 10b.
The NVM 30 and a traveling sensor 40 that outputs traveling pulses of a number corresponding to the traveling distance, and the first and second coils L ₁ and L ₂ of the cross coil L are connected to each other.

The RAM 10a has a data area for storing various data and a work area used for various processing operations. The ROM 10b stores a control program for causing the CPU 10 to perform various processing operations. .

The dip switch 20 (corresponding to a period selection means) has two switches 21 which can switch between two states of "0" and "1" as shown in a plan view in FIG. And “0”,
It is configured to output a signal according to the setting state of “1”.

The NVM 30 (corresponding to the period storage means and the external storage element) includes two bits "00", "01", "10", and "11" as shown in FIG. Address, and four different cycle times T _{1 to} T ₄ (T ₁ > T) are assigned to each address location.
₂ > T ₃ > T ₄ ) are stored as selection candidates for the update cycle time T (corresponding to the supply update cycle).

Next, the processing performed by the CPU 10 according to the control program stored in the ROM 10b will be described with reference to the flowcharts of FIGS.

When the microcomputer 10 is started by turning on a power supply (not shown) and the program is started, the CPU 10
As shown in FIG. 5, a cycle acquisition process (step S1),
The driving process (step S3) is repeated in order.

In the cycle acquisition process of step S1, the states of the switches 21 and 21 are read based on the output signal of the dip switch 20, as shown in the subroutine flowchart in FIG. 6 (step S1a). Next, it is confirmed whether or not there is a change between the read switch state and the previous switch state (step S1b).

If there is no change in the switch state of the dip switch 20 (N in step S1b), the cycle obtaining process is terminated and the process returns to the main routine of FIG. 5. If there is a change (Y in step S1b), the dip period time T ₁ through T ₄ reads the address portion of the switch state to match NVM30 update period time T of the switch 20 (step S1c), after setting the period time T ₁ through T ₄ read as an update cycle time T (Step S1d), the cycle obtaining process ends, and the process returns to the main routine of FIG.

Next, in the driving process in step S3,
As shown in the flowchart of the subroutine in FIG. 7, after the microcomputer 10 is started, or after a step S described later.
It is confirmed whether or not the update cycle time T has elapsed since the last time the processing of 3g was completed (step S3a). If it has not elapsed (N in step S3a), step S3a is repeated until it has elapsed, and (Step S3
a), the cycle of the traveling pulse is measured by counting the number of reference clocks generated by the internal clock during one cycle of the traveling pulse from the traveling sensor 40 (step S3b).

Next, a deflection angle θ corresponding to the measured cycle of the running pulse is calculated from a calculation formula stored in the RAM 10b (step S3c), and then a filtering process is performed (step S3d).

In this filter processing, the shake angle θ calculated by the calculation in step S3c and the shake angle θ calculated previously
Is within a predetermined range (eg, ± 1). If the difference is within the range, the deflection angle θ is set to the previously calculated deflection angle θ. θ is the deflection angle θ calculated this time.

Next, a smoothing process is performed (step S3e). In the smoothing process, it is confirmed whether or not the current swing angle of the hands (not shown) matches the swing angle θ after the filtering process in step S3d. If they match, the shake angle θ after the filter processing is left unchanged, and if they do not match, the shake angle θ after the filter processing is corrected by a predetermined angle increase or decrease so as to move away from the current shake angle of the hands. .

Subsequently, sine and cosine data corresponding to the deflection angle θ after the filtering process and the smoothing process are generated (step S3f). Next, a duty pulse signal having a duty ratio corresponding to the generated sine and cosine data is generated. Based on each terminal a ₁ of the first coil L ₁ of the cross coil L,
between a _2, it supplies the first pulse current I ₁ corresponding to the sine data of the deflection angle theta, the second of the terminals b ₁ of the coil L _2, b between ₂ and cosine data of the deflection angle theta after supplying the corresponding second pulse current I ₂ (step S3g),
The drive processing ends, and the process returns to the main routine of FIG.

The generation of the sine and cosine data corresponding to the deflection angle θ after the filtering process and the smoothing process in step S3f is described in Japanese Unexamined Patent Publication No.
As in the sin function generating circuit 3 of the driving device disclosed in Japanese Patent Application Laid-Open No. 2011167, first, sine data of the deflection angle θ is generated, and cosine data of the deflection angle θ is generated by shifting the phase of the sine data by 90 °. Can be done with

However, the present invention is not limited to this. Alternatively, the sine data of the deflection angle θ and the cosine data of the deflection angle θ may be individually generated. On the contrary, the cosine data of the deflection angle θ is generated first. Alternatively, the sine data of the deflection angle θ may be generated by shifting the phase of the sine data by 90 °.

As is clear from the above description, in the present embodiment, the cycle setting means 10A in the claims corresponds to steps S1c and S1 in the flowchart of FIG.
The drive pulse signal in the claims is composed of a duty pulse signal corresponding to sine and cosine data, and first and second pulse currents I ₁ and I ₂ .

Next, the operation (operation) of the driving device of the present embodiment configured as described above will be described.

First, basically, every time the update cycle time T comes, the cycle of the running pulse after the running speed is changed is measured, and the corresponding shake angle θ is calculated, and the filtering process and the smoothing process are performed. Is performed, the magnet rotor Mg is rotated to the position of the deflection angle θ, whereby the position corresponding to the traveling speed of the vehicle is indicated by the pointer.

When the running speed of the vehicle changes and the cycle of the running pulse from the running sensor 40 changes, the time when the update cycle time T has passed since the last time the magnet rotor Mg was rotated to the position of the deflection angle θ. Then, the magnet rotor Mg is rotated at a position of the deflection angle θ corresponding to the changed running speed, and a position corresponding to the changed running speed is indicated by the pointer.

The change in the position indicated by the pointer with the change in the traveling speed is, as described above, every time the update cycle time T comes, but in a state where both the switches 21 and 21 of the dip switch 20 are set to "0". In this case, the cycle time T ₁ stored at the address “00” of the NVM 30 is set as the update cycle time T. Therefore, the change in the point indicated by the pointer due to the change in the traveling speed is every cycle time T _1. .

Similarly, if the setting states of the switches 21 and 21 are “01”, “10” and “11”, the NVM 30
The cycle times T ₂ , T ₃ , and T ₄ stored at the corresponding address locations of “01”, “10”, and “11” are respectively set as the update cycle time T, so that the change with the change in the traveling speed occurs. The change of the position indicated by the pointer is the cycle time T ₂ , T ₃ ,
The each T _4.

Therefore, from the relationship of T ₁ > T ₂ > T ₃ > T ₄ , the setting of the two switches 21 and 21 of the DIP switch 20 is set such that the closer the value of the corresponding NVM 30 to the address portion is, the larger the setting is. , The update cycle time T becomes shorter,
As a result, the response of the instruction operation of the pointer to the change in the traveling speed becomes faster, and the setting is more suitable for an instrument of a vehicle type in which accuracy of the speed display is important.

Conversely, as the setting of the two switches 21 and 21 of the dip switch 20 becomes closer to the address portion where the value of the corresponding NVM 30 is smaller, the update cycle time T becomes longer, and the travel time becomes longer. The response of the instruction operation of the pointer to the change in the speed becomes slower, and if anything, the setting is suitable for an instrument of a vehicle type in which the visibility of the speed display by the pointer is important.

Note that the update cycle time T is defined as cycle times T _{1 to} T ₄
If the sensitivity of the pointer's instruction operation to the change in the traveling speed does not match the specification of the instrument regardless of which of the settings is made, for example, "00", "01",
"10", the contents of each address location of the "11", or rewritten to different periods time T ₅ through T ₈ is the period time T ₁ through T _4, "00", "01", "10", "11 another may be replaced NVM30 the cycle time T ₅ through T ₈ is written to each address location of the ".

As described above, according to the driving device of the present embodiment, the deflection angle θ of the pointer is calculated from the period of the traveling pulse from the traveling sensor 40, and the filtering and smoothing processes are performed on the deflection angle θ. , Sine and cosine data corresponding to the deflection angle θ, and the first pulse of the cross coil L is generated based on a duty pulse signal having a duty ratio corresponding to the sine and cosine data.
And between the terminals a ₁ and a _{2 of} the second coils L ₁ and L ₂ and between the terminals b ₁ and b ₂ , the first and second pulse currents I ₁ , I 2 corresponding to the sine and cosine data of the deflection angle θ. to supply the I _2,
An update cycle time for recalculating the deflection angle θ from the travel pulse to reflect the change in the cycle of the travel pulse due to the speed change in the location indicated by the pointer when indicating the location according to the travel speed of the vehicle with the pointer. T is set to NVM by setting two switches 21 and 21 of the dip switch 20.
30 can be selected and set from the _four cycle times T _{1 to} T ₄ stored in the memory 30.

Therefore, the update cycle time T is set to the cycle time T₁
Cycle time T_TwoIs the variation in running speed
The response of the pointer to the change in the point indicated by the
And the cycle time T_TwoCycle time T_ThreeWho
, And furthermore, the cycle time T _ThreeCycle time than
T_FourIs more responsive to changes in the location indicated by the pointer.
Feeling, and therefore,
4 types with different specifications of the sensitivity of the reaction of the change of the point indicated by the pointer
Single instrument without replacing CPU 10
The device can handle this.

In this embodiment, four candidates for the update cycle time T to be stored in the NVM 30 are provided.
The number of selection candidates of the update cycle time T to be stored in 30 is 2
Any number may be used as long as it is more than one.

In this embodiment, the case where the drive unit except the NVM 30 is constituted by the integrated circuit CPU 10 has been described. However, from the measurement of the cycle of the traveling pulse from the traveling sensor 40, the cross coil L for the first and second pulse current I _1, the driving device has a structure that combines a plurality of circuits for performing individually the processes up to the supply of the I ₂ to the first and second coil L _1, L ₂ also Needless to say, the present invention is applicable.

Further, in this embodiment, the travel sensor 40
The case where the present invention is applied to the driving device of the speedometer that displays the running speed of the vehicle based on the running pulse from the above has been described. It can be widely applied to a driving device that generates a driving pulse signal from a running pulse generated with the running of a vehicle and supplies the driving pulse signal to a cross coil to drive a magnet rotor, such as a tachometer that displays the engine speed based on the signal. Of course there are.

In the present embodiment, the update cycle time T, which is the cycle for measuring the cycle of the running pulse from the running sensor 40, is used as the four cycle times T ₁ to T4 stored in the NVM 30.
Configuration has been described for selecting from T _4.

However, according to the present invention, even if the period of the running pulse changes, the first and second pulse currents I ₁ and L ₁ supplied to the first and _second coils L ₁ and L ₂ of the cross coil L are changed.
The present invention can be widely applied to a driving device having a configuration for preventing I ₂ from changing until a predetermined period comes. In this case, the NVM 30 supplies the first and second pulse currents I ₁ , I ₁ , for period I ₂ will cause no change to follow the cycle change of the running pulse, so that the plurality of periodic time satisfying selection candidate stored.

Further, in this embodiment, the update cycle time T
Four cycle times T that are selection candidates for ₁~ T_FourRewrite
Possible and exchangeable configuration for storing in NVM 30
Has been described, for example,
It can be stored in a replaceable ROM,
There is a configuration that can be stored in a rewritable NVM
Well, non-rewriteable and non-replaceable RO
M has four cycle times T ₁~ T_FourIs configured to memorize
Of course, it is possible.

[0056]

As described above, according to the driving apparatus for a cross-coil type instrument according to the first aspect of the present invention, the driving pulse generated according to the running of the vehicle is changed according to the pulse interval of the running pulse. A drive pulse signal having a duty ratio is generated, and the drive pulse signal is supplied to a cross coil while periodically updating the drive pulse signal with the newly generated drive pulse signal. In the driving device of the coil-type instrument, the operation of generating the driving pulse signal from the running pulse, and the electric element related to the operation of supplying the driving pulse signal to the cross coil are provided separately, and A cycle storage means for storing a plurality of drive pulse signal supply update cycles; and a plurality of the supply pulses stored in the cycle storage means. A cycle selection unit that selects a single supply update cycle from an update cycle, and a supply update cycle of the drive pulse signal to the cross coil, the plurality of supply update cycles stored in the cycle storage unit, Cycle setting means for setting the supply update cycle selected by the cycle selection means, and for each supply update cycle set by the cycle setting means, the drive pulse signal to be supplied to the cross coil is newly generated. The driving pulse signal is updated.

For this reason, even if the response of the pointer operation to the variation of the running speed or the engine speed is different, the supply update cycle according to the sensitivity is stored in the plurality of supply update cycles stored in the cycle storage means. What is necessary is just to select from the cycle by the cycle selection means, therefore, without replacing the electric element related to the operation of generating the drive pulse signal from the running pulse and the operation of supplying the drive pulse signal to the cross coil,
A single drive can be used for a plurality of types of instruments having different reaction sensitivities.

According to the second aspect of the present invention, since the cycle storage means is constituted by a rewritable nonvolatile memory, a plurality of cycles can be stored in the cycle storage means. By changing the contents of the supply update cycle by rewriting the nonvolatile memory, it is possible to easily change the group of types of instruments that can be supported from one type group to another type without replacing electrical elements, Can be enhanced.

According to a third aspect of the present invention, the electric element is constituted by a dedicated integrated circuit, and the period storage means is connected to the integrated circuit. And an external storage element that can be replaced independently of the integrated circuit.

For this reason, by changing the contents of the plurality of supply update periods stored in the period storage means by exchanging the external storage element, the type of the meter that can be dealt with without exchanging the integrated circuit integrated electric element. Can easily be changed from one type group to another type group, and the versatility can be improved.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a driving device of a cross coil type instrument according to the present invention.

FIG. 2 is a block diagram illustrating an electrical configuration of a driving device of the cross-coil instrument according to the embodiment of the present invention.

FIG. 3 is a plan view of the dip switch shown in FIG.

FIG. 4 is an explanatory diagram showing storage contents of a nonvolatile memory of FIG. 2;

FIG. 5 shows a one-chip microcomputer of FIG.
5 is a flowchart of a main routine showing a process performed according to a program stored in M.

FIG. 6 is a flowchart of a subroutine showing a period obtaining process of FIG. 5;

FIG. 7 is a flowchart of a subroutine showing a driving process of FIG. 5;

FIG. 8 is a functional block diagram of a conventional driving device for a cross-coil type instrument.

[Explanation of symbols]

 Reference Signs List 10 electric element 10a RAM 10b ROM 10A cycle setting means 20 cycle selection means 30 cycle storage means (non-volatile memory, external storage element) L cross coil Mg magnet rotor

Claims (3)

[Claims] 1. A driving pulse signal having a duty ratio corresponding to a pulse interval of the traveling pulse is generated from a traveling pulse generated as the vehicle travels, and the driving pulse signal is replaced with the newly generated driving pulse signal. In a driving device for a cross-coil instrument that supplies a cross coil while periodically updating the driving pulse signal and drives the magnet rotor with the driving pulse signal, the operation of generating the driving pulse signal from the running pulse;
A period storage unit that is provided separately from an electric element related to an operation of supplying the drive pulse signal to the cross coil, and stores a plurality of supply update periods of the drive pulse signal to the cross coil; Cycle selection means for selecting a single supply update cycle from the plurality of supply update cycles stored in the storage section, and the cycle selection means among the plurality of supply update cycles stored in the cycle storage means Wherein the drive pulse signal to be supplied to the cross coil is updated to the newly generated drive pulse signal for each supply update cycle selected by: . 2. The driving device for a cross-coil type instrument according to claim 1, wherein said period storage means comprises a rewritable nonvolatile memory. 3. The electric element is constituted by a dedicated integrated circuit, and the period storage means is constituted by an external storage element connected to the integrated circuit and exchangeable independently of the integrated circuit. Item 3. A driving device for a cross-coil type meter according to item 1 or 2.