JPS61286759A - Analogue indicator - Google Patents

Abstract

PURPOSE:To perform accurate indication by smoothly displacing a pointer without accompanying hysteresis, by displacing the pointer to the position corresponding to the level of an analogue signal while said pointer is minutely vibrated. CONSTITUTION:A window comparator 60 generates a first output signal in a predetermined duty ratio in connection with the low level region of each saw-tooth wave signal from a saw-tooth wave generator 50 and a window comparator 70 intermittently generates a second output signal having phase different from that of the first output signal in a predetermined high duty ratio in connection with the region other than the low level region of each saw-tooth signal from the saw-tooth wave generator 50. The first and second signals are alternately inputted to the movable coil driving part of a meter main body M so as to mutually differentiate the phase of both signals. By this method, the movable coil driving part generates intermittent driving force and smoothly revolves a pointer P against the contact frictional force between the pointer and a bearing while said pointer is minutely vibrated and accurately displaces the pointer P to the position corresponding to the level of an analogue signal regardless of the magnitude of analogue quantity.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an analog indicator.

[Prior art]

Conventionally, in this type of analog indicator, as disclosed in Japanese Utility Model Application No. 56-84751, for example, the indicator shaft of the pointer is connected to the drive part through a bearing provided on one side of the instrument body. and generating an output pulse with a duty ratio corresponding to the DC voltage by comparing a DC voltage corresponding to the measured quantity with a triangular wave, and generating an intermittent driving force from the drive unit in response to the output pulse, The indicator shaft is caused to vibrate slightly by intermittent driving force from the drive unit, and is rotated smoothly against the contact friction force between the indicator shaft and the indicator, and the analog quantity is indicated by the pointer with hysteresis. There are some things that I tried to do without having to do it.

[Problem that the invention seeks to solve]

However, in such a configuration, the variation range of the measured quantity is wide from small values to large values, so when the measured quantity is small, the interval between the output pulses is wide, and the minute vibrations actually cause the needle to oscillate. On the other hand, when the quantity to be measured is large, the output pulse generation interval is narrow, and the driving section cannot cause the pointing shaft to vibrate slightly, resulting in an increase in pointing hysteresis of the pointer.

In order to deal with this problem, the present invention aims to cause the indicator axis of the pointer of an analog indicator to vibrate slightly by a signal of a constant frequency, regardless of changes in the analog quantity. .

[Means for solving problems]

In solving this problem, the structural features of the present invention are as follows:
detecting means for detecting an analog quantity and generating a series of pulse signals at a frequency proportional to the detected analog quantity; converting means for converting the frequency of each of the pulse signals into an analog signal having a level proportional to the frequency; duty signal generating means for generating a signal as a signal; output signal generating means for intermittently generating an output signal representing the level of the analog signal at the duty ratio in response to the duty signal; A driving part that intermittently generates a driving force, and a pointer that instructs the level of the analog signal by displacing it to a corresponding position while vibrating slightly in response to the intermittent driving force from the WJA moving part. In the analog indicator, the duty signal generating means comprises:
a predetermined low duty ratio and a predetermined high duty ratio, each having an integral signal generating means for generating an integral signal at a predetermined period, and determined in relation to a predetermined low level region and a predetermined high level region higher than the predetermined low level region of the level of the integral signal; generates first and second duty signals as the duty signals, and the output signal generating means generates a first output signal as the output signal at the predetermined low duty ratio in response to the first duty signal. and intermittently generates a second output signal having a level proportional to the level of the analog signal at the predetermined high duty ratio in response to the second duty signal; The driving force is intermittently generated in response to the first and second output signals.

[Effect]

By configuring the present invention in this way, the duty signal generating means generates the first and second duty signals at the predetermined low duty ratio and the predetermined high duty ratio according to the level change of each of the integral signals. and the output signal generating means intermittently generates the first output signal at the predetermined low duty ratio in response to the first duty signal, and In response to a second duty signal, a second output signal having a level proportional to the level of the analog signal is intermittently generated at the predetermined high duty ratio and out of phase with the first output signal; The unit intermittently generates a driving force in response to the first and second output signals to slightly vibrate the pointer and displace it to a position corresponding to the level of the analog signal. If the amount is small, although the level of the second output signal becomes low, the first output signal effectively acts on the generation of intermittent driving force from the drive unit, causing the pointer to cause unnecessary needle vibration. On the other hand, when the analog amount is large, the first and second
Together, the output signals effectively act on the generation of intermittent driving force from the drive section, causing the pointer to accurately vibrate slightly without unnecessary hysteresis, thereby instructing the analog quantity. Therefore, the pointer can be accurately vibrated and smoothly displaced over a wide variation range of the analog quantity to give correct instructions.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
The figure shows an example in which the present invention is applied to a moving coil type speed needle, and this speed needle includes an instrument body M connected to a DC power source B via an ignition switch IG of the vehicle and a speed sensor 10. ing. The speed sensor 10 includes a permanent magnet 12 connected to an output shaft of a transmission (not shown) via a speed-making cable 11 of the vehicle, a reed switch 13 arranged to have a magnetic relationship with the permanent magnet 12, and the reed switch. 13 and a resistor 14 connected in series. Accordingly, the speed sensor 10 receives the power supply voltage from the DC power source B through the resistor 1 when the ignition switch IG of the vehicle is opened.
4, the permanent magnet 12 is activated, and the rotational position of the permanent magnet 12 is repeatedly detected by opening and closing the reed switch 13.
Each of these detection results is generated as a series of pulse signals having a frequency proportional to the traveling speed of the vehicle.

In such a case, a series of pulse signals having the same frequency as each pulse signal from the reed switch 13 is generated at the common connection terminal between the ignition switch IG and the resistor 4.

As shown in FIGS. 1 to 3, the meter body M includes a pointer P and a movable coil drive unit connected to a support shaft P1 of the pointer P, which is supported by a bearing Br provided in a part of the meter body M. M.C.
The movable coil drive section M of this instrument body M
C is the ignition switch IG at its one side input terminal.
It is connected to the DC power supply B via the input terminal, and is grounded via a constant current circuit 90, which will be described later, at the other side input terminal.

The buffer circuit W1r20 sequentially shapes the waveform of each pulse signal from the speed sensor 1o to generate shaped pulses. Frequency-voltage converter 30 (hereinafter referred to as F-V converter 30)
converts the frequency of the shaped pulse from the buffer circuit 20 into an analog voltage proportional to it. Constant voltage generation circuit 4
0 receives the power supply voltage from the DC power supply B through the ignition switch IC and generates a constant voltage. The sawtooth wave generation circuit 50 generates a sawtooth wave signal at a predetermined frequency (for example, about 100.Hz). As shown in FIGS. 1 and 4, the window comparator 60 includes a voltage divider 61 connected to the constant voltage circuit 40, and a pair of comparators 62 and 63 connected to the voltage divider 61 and the sawtooth wave generator 50. The voltage divider 61 includes resistors 61 connected in series with each other.
a, 61b, and 61C divide the constant voltage from the constant voltage circuit 40 to generate divided voltage VL from the common terminal of both resistors 61a and 61b, and generate divided voltage VU from the common terminal of both resistors 61b and 61c. . In such a case, both partial pressures V
The resistors 61a, 61b, 6. The resistance value of the IC is determined.

Each comparator 62, 63 connects each resistor 62a, 63a and each diode 62b, 63b when the level of each sawtooth signal from the sawtooth generator 50 is between the divided voltages VL and VtJ from the divided voltage a61. (See FIG. 4) between both diodes 62b.

A high level signal is generated from the common cathode terminal of 63b. Further, the high level signals from each of the comparators 62 and 63 become low level when the level of each sawtooth wave signal from the sawtooth wave generator 50 is not between the divided voltages VL and VU. This means that the wind comparator 60 responds to each sawtooth signal from the sawtooth generator 50 to a high level at a predetermined duty ratio (5%) in relation to the low level region of each sawtooth signal. means to generate a signal.

As shown in FIGS. 1 and 5, the window comparator 70 includes a voltage divider 71 connected to the low voltage circuit 40, and a pair of comparators 72 and 73 connected to the voltage divider 71 and the sawtooth wave generator 50. The voltage divider 71 divides the constant voltage from the constant voltage circuit 40 by each resistor 71a, 71b, 71c connected in series with each other, and divides the constant voltage from the constant voltage circuit 40 into two resistors 71a, 71.
A divided voltage vi! is applied from the common terminal of b! At the same time, a divided voltage Vu is generated from the common terminal of both resistors 71b and Tic. In such a case, each resistor 7 is set so that the difference between the divided voltages Vu and VJ corresponds to 75% of the full width of the rising level of each of the sawtooth signals in a region other than the low region of the rising level.
The resistance values of 1"a, 71b, and 71c are determined. Therefore, Vu>V7!>VU>VL holds true.

Each of the comparators 72 and 73 determines whether each resistor ? ja, 73a and each diode? A high level signal is generated from the common cathode terminal of both diodes 72b and 73b through the diodes 72b and 73b (see FIG. 5). This means that the wind comparator 70 responds to each sawtooth signal from the sawtooth generator 50 at a predetermined high duty ratio (75%) with respect to regions other than the low level region of each sawtooth signal. ) means to generate a high level signal.

The constant voltage circuit 80 includes two transistors 811 connected in series [anti-82
．． 83. Comparator 84 and both transistors 85.
86, and the transistor 81 connects both diodes 62b and 63 of the window comparator 60 at its base.
b (see FIGS. 1 and 4). Thus, the transistor 81 is intermittently turned on at the predetermined low duty ratio in response to each high level signal from the window comparator 60. Further, the constant current circuit 80 is connected to both series resistors 82.8 from the constant voltage circuit 40.
3 receives a constant voltage, and under intermittent conduction of the transistor 81, the emitter of the transistor 85 and both resistors 82.
Both transistors 85 and 86 are intermittently turned on so that the common connection terminal 83 has the same potential. This means that the intermittent current flowing into the meter body M under intermittent conduction of both transistors 85 and 86 is pulsed at a constant value as indicated by symbol a in FIG. This means that it is defined by a low duty ratio.

As shown in FIG. 1, the constant current circuit 90 includes transistors 91. Comparator 92 and both transistors 93.94
The transistor 91 has both diodes 72b and 73b of the window comparator 70 at its base.
(See Figure 5).

Therefore, the transistor 91 is connected to the window comparator 7.
In response to each high level signal from 0 to 0, it is intermittently turned on at the predetermined high duty ratio. Further, the constant current circuit 90 connects the F-■ converter 3 to the inverting input terminal of the comparator 92.
0, so that the emitter of the transistor 93 and the inverting input terminal of the comparator 92 have the same potential under intermittent conduction of the transistor 91.
Both transistors 93 and 94 are made conductive intermittently. This means that the intermittent current flowing into the meter body M under intermittent conduction of both transistors 93 and 94 has a peak value proportional to the analog voltage, as shown by the symbols in FIG. This means that it is defined by the predetermined high duty ratio.

In this embodiment configured as described above, when the vehicle is in a running state with the ignition switch IG closed, a series of pulse signals are generated from the reed switch 13 of the speed sensor 10, and the resistor 14 and the ignition switch A series of pulse voltages is generated from the common connection terminal with the IG. Then, the buffer circuit 20
The F-V converter 30 generates shaped pulses in response to each pulse signal from 3 in turn, and the F-V converter 30 generates an analog voltage in response to each of these shaped pulses. Further, the window comparator 60 outputs both divided voltages V from the voltage divider 61 in relation to the low level region of each sawtooth wave signal from the sawtooth wave generator 50.
A high level signal is generated at the predetermined low duty ratio under L and VU, and the transistor 81 of the constant current circuit 80 is intermittently turned on. On the other hand, the window comparator 70 sets the predetermined high duty ratio of both the divided voltages Vl and Vu from the voltage divider 71 in relation to an area other than the low level area of each sawtooth wave signal from the sawtooth wave generator 50. A high level signal is generated at , and the transistor 91 of the constant current circuit 90 is made conductive intermittently.

Then, under the action of the constant current circuit 80 based on the intermittent conduction of the transistor 81 as described above, the current a (see FIG. 6) changes in relation to the voltage at the common connection terminal of both the resistors 82 and 83. The transistor 91 as described above intermittently flows into the meter main body M at the predetermined image duty ratio with a predetermined peak value and is out of phase with this intermittent current a.
Under the action of the constant current circuit 90 based on intermittent conduction, a current b (see FIG. 6) is intermittently applied to the meter body M at the predetermined high duty ratio with a peak value proportional to the analog voltage. flows into.

In this way, when the intermittent currents a and b alternately flow into the meter body M with different phases from each other, the movable coil drive section MC of the meter body M receives the intermittent currents a and b alternately. An intermittent driving force is generated, and the support shaft P1 of the pointer P receives the intermittent driving force and vibrates slightly, while smoothly rotating against the contact friction force with the bearing Br, and the pointer P rotates smoothly. Support shaft P1
The driving speed of the vehicle (corresponding to the frequency of each of the pulse voltages) is indicated while vibrating slightly.

In such a case, the higher the running speed of the vehicle, that is, the analog voltage, the higher the total average current flowing into the moving coil drive drive unit MC will be, the higher the average value of the intermittent current a (labeled La in FIG. 7).
) and the average value of the intermittent current S increases as shown by the symbol Ls (see Figure 7) as the running speed increases, so the running speed of the vehicle, that is, the total average current L
The pointer P can be made to swing in proportion to s. In addition, when the running speed of the vehicle is low, the peak value of the intermittent current a becomes small, but the intermittent current a is maintained at the low duty ratio with a constant peak value, so that the pointer P vibrates slightly. On the other hand, when the running speed of the vehicle is high, both intermittent currents a.

Microvibration of the pointer P can be ensured with each duty ratio b. Therefore, over a wide range of running speeds of the vehicle, accurate indications can always be made without any undesirable needle vibration or hysteresis phenomenon under the appropriate micro-vibration of the pointer P. In addition, since the slight vibration of the pointer P is specified by each of the predetermined image duty ratios and the predetermined high duty ratio, which are unrelated to the running speed of the vehicle, the pointer P resonates due to the resonant frequency of the moving coil portion MC. This phenomenon does not occur, and the scale of the instrument body M can be made equal in the low running speed region.

Next, a modification of the above embodiment will be explained with reference to FIG. 8. In this modification, a transistor 87 is added to the constant current circuit 80 described in the above embodiment, and an F
The configuration is characterized by the fact that the comparator circuit 100 is connected between the -V converter 30, the constant voltage circuit 40, and the constant current circuit 80. The comparison circuit 100 includes a voltage divider 101 connected to the constant voltage circuit 40, and this voltage divider 101 and the F-V converter 30.
The voltage divider 101 divides the constant voltage from the constant voltage circuit 40 by the series resistors 101a and 101b, and outputs the divided voltage from the common connection terminal of the series resistors 101a and 101b. Occur.

In such a case, the resistance values of both series resistors 101a and 101b are determined so that the divided voltage from the voltage divider 101 corresponds to a predetermined low speed (for example, about 0.5 km/h) of the vehicle.

Comparator 102 generates a high level signal (or low level signal) when the analog voltage from F-V converter 30 is lower (or higher) than the divided voltage from voltage divider 101. The transistor 87 becomes conductive (or non-conductive) in response to the high level (No. 8 (or low level signal)) from the comparator 102. This means that the transistor 87 becomes conductive (or non-conductive). This means that conduction of both transistors 85 and 86 is prohibited (or allowed) in response to , regardless of the action of transistor 81.The other configurations are the same as in the previous embodiment.

In this modified example configured in this way, when the running speed of the vehicle is lower than the predetermined low speed, the analog voltage from the F-V converter 30 is lower than the divided voltage from the voltage divider 101, so the comparator 102 generates a high level signal, in response to which transistor 87 conducts and prohibits both transistors 85 and 86 from conducting. Also, at this time, in the constant current circuit 90, since the analog voltage from the F-V converter 30 is low, the peak value of the intermittent current is maintained very low, so the inflow current into the meter main body MC is almost close to zero. As a result, the vehicle's 0.5k11+/
At a traveling speed of less than h, the pointer P will indicate the traveling speed as almost zero without any slight vibration, so the instruction of the pointer P can be correctly recognized without causing any discomfort.

Furthermore, when the traveling speed of the vehicle becomes higher than 0.5ka+/h, the analog voltage from the F-V converter 30 becomes higher than the divided voltage from the voltage divider 101, so the comparator 102 generates a low level signal. The conduction of the transistor 87 is prohibited to allow the operation of the constant current circuit 80 described in the previous embodiment. Note that other effects are the same as those in the above embodiment.

In the above embodiments and variations thereof, an example in which the present invention is applied to a moving coil type speed needle has been described, but instead of this, the present invention can be applied to various moving coil type analog indicators. In such a case, the present invention is applicable to various types of analog indicator needles without being limited to the moving coil type.

[Brief explanation of drawings]

Fig. 1 is an electric circuit diagram showing an embodiment of the present invention, Fig. 2 is a cross-sectional view of the instrument body in Fig. 1, Fig. 3 is a partially cutaway front view of the same, and Figs. 4 and 5 are also similar. Figure 1 is a detailed circuit diagram of each window comparator, Figure 6 is a time chart of the intermittent current flowing into the instrument body in Figure 1, and Figure 7 is a detailed circuit diagram of each window comparator.
The figure is a graph showing the relationship between the running speed of the vehicle and the total average current flowing into the meter body, and FIG. 8 is an electric circuit diagram showing a modification of the above embodiment. Explanation of symbols 10...Speed sensor, 30...F-V converter, 50
,... Sawtooth wave generator, 60.70... Wind comparator, 80.90... Constant current circuit, M... Meter body, P... Pointer.

Claims (1)

[Claims] detecting means for detecting an analog quantity and generating a series of pulse signals at a frequency proportional to the detected analog quantity; converting means for converting the frequency of each of the pulse signals into an analog signal having a level proportional to the frequency; duty signal generating means for generating a signal as a signal; output signal generating means for intermittently generating an output signal representing the level of the analog signal at the duty ratio in response to the duty signal; A drive unit that intermittently generates a drive force, and a pointer that instructs the level of the analog signal by displacing it to a corresponding position while vibrating slightly in response to the intermittent drive force from the drive unit. In the analog indicator, the duty signal generating means has an integral signal generating means for generating an integral signal at a predetermined period,
the first and second pulses at a predetermined low duty ratio and a predetermined high duty ratio respectively determined in relation to a predetermined low level region and a higher predetermined high level region of the level of the integrated signal;
generate a duty signal as the duty signal,
The output signal generating means intermittently generates a first output signal as the output signal at the predetermined low duty ratio in response to the first duty signal, and generates the first output signal at the predetermined low duty ratio in response to the second duty signal. a second signal having a level proportional to the level of the analog signal at a high duty ratio;
the drive unit intermittently generates an output signal, and the drive unit
and an analog indicator that intermittently generates a driving force in response to the second output signal.