JP2990396B2 - Display switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display switching device used for a flow meter or the like.

[0002]

2. Description of the Related Art As an example of a conventional display switching device, FIG.
Or those shown in FIG. This display switching device is adapted to be used in an ultrasonic vortex flowmeter. In the figure, a reed switch 2 is connected to a DC power supply 1, and the reed switch 2 is turned on / off by a magnetic field generated by a permanent magnet 3, and outputs a trigger signal A which becomes high when turned on. The signal is output to a one-shot multivibrator 4 connected to the switch 2. The one-shot multivibrator 4 is connected to a control unit 5 composed of a microcomputer. The one-shot multivibrator 4 outputs a pulse signal B to the high-state in response to a trigger of the trigger signal A to the control unit 5. .
The memory 6 has a conversion parameter (hereinafter referred to as an instantaneous value parameter) P ₁ used for calculating an instantaneous flow rate, a conversion parameter (hereinafter referred to as an integrated value parameter) P ₂ used for calculating an integrated flow value, and a conversion used for calculating a temperature value. Parameters (hereinafter referred to as temperature value parameters) P ₃ , conversion parameters (hereinafter referred to as pressure value parameters) P ₄ used for calculating pressure values, and conversion parameters (hereinafter referred to as various parameters) P ₅ used for calculating other data, etc. Are stored. Reference numeral 7 denotes a display. The display 7 displays each parameter of the memory 6 in the order shown in FIG. 11 which is set in advance for each pulse input of the pulse signal B. In the figure, reference numeral 8 denotes a sensor unit for detecting a variable such as a flow rate and a temperature.

[0003]

By the way, there may be a case where it is desired to quickly confirm a specific parameter during the flow measurement or the like. In such a case, the display switching device described above uses the parameters P ₁ , P ₂ , P ₃ , and P ₄ , there is a problem that desired parameters cannot always be displayed quickly because the display order is predetermined. In particular, this problem has become remarkable due to an increase in the number of parameters associated with recent intelligent flow meters.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display switching device capable of quickly displaying desired parameters with a simple configuration.

[0005]

In order to achieve the above object, the present invention divides a plurality of parameters into a plurality of groups.
A memory for storing and split, and a control means for displaying on the display means the parameter is read from the memory, the control means discriminates the polarity of the input signal, based on the determination result, the parameter And a selection signal generation circuit for generating a plurality of different selection signals for selecting the group in which the group is stored .

[0006]

With this configuration, the selection signal generation circuit determines the polarity of the input signal whose polarity changes alternately, and a plurality of parameters are determined based on the determination result.
Since a plurality of different selection signals for selecting a group to be stored are generated, selection of a group corresponding to the selection signal from a memory and display of parameters included in the group are performed. Display on the means becomes possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A display switching device according to an embodiment of the present invention will be described below with reference to FIGS. 8 to FIG.
The same parts as those shown in FIG. 11 are denoted by the same reference numerals, and the description thereof will be omitted. In the figure, a Hall element 10 is interposed between a reed switch 2 connected to a DC power supply 1 and the ground. The Hall element 10 is arranged in the immediate vicinity of the reed switch 2, receives the influence of the permanent magnet 3 at the same time as the reed switch 2, and generates a voltage between the pair of terminals 10a and 10b. In this case, the permanent magnet 3 changes its direction by rotating the permanent magnet 3 to alternately change the N and S poles, and the reed switch 2 is driven by any of the N and S poles. While on
The Hall element 10 generates a voltage between the pair of terminals 10a and 10b in a direction corresponding to the N and S poles. The reason why the reed switch 2 is provided here is to aim at so-called power saving, in which no current flows through the circuit when the permanent magnet 3 is not used.

A non-inverting input terminal 11n and an inverting input terminal 11r are connected to a pair of terminals 10a and 10b of the Hall element 10, respectively, to provide a Hall element side operational amplifier 11. The Hall element side operational amplifier 11 is connected to the pair of terminals 10a and 10b. 3 (a), the voltage between the terminals 10a and 10b is differentially amplified, and as shown in FIG. 3 (a), an amplified pulse signal D whose polarity alternates with the change of the N / S pole of the permanent magnet 3 with respect to the Hall element 10 is generated. Output. In this case, the pulses d ₁ , d _3, ... Of the positive polarity are obtained from the S pole of the permanent magnet 3, and the pulses d ₂ , d ₄ ,. Note that the positive polarity pulse d ₁ ,
d ₃ ... a by N pole of the permanent magnet 3 obtained, it may be configured to obtain a negative S pole of the pulse d _2, d ₄ ... permanent magnet 3.

A non-inverting input terminal 12n is connected to the output terminal of the operational amplifier 11 on the Hall element side, and a first operational amplifier 12 as a positive pulse detector is provided. The output terminal is connected to an inverting input terminal 13r, and a second operational amplifier 13 serving as a negative pulse detector is provided. The first operational amplifier 12 inputs the amplified pulse signal D to a non-inverting input terminal 12r, and a first reference voltage V ₁ as a threshold value for positive polarity pulses d ₁ , d ₃ . Is supplied via the terminal 14, and outputs a first comparison signal E which becomes high when the value of the amplified pulse signal D reaches the _first reference voltage V1.

The second operational amplifier 13 inputs the amplified pulse signal D to an inverting input terminal 13r, and supplies a _second threshold as a threshold for negative pulses d ₂ , d ₄ ... To a non-inverting input terminal 13n. received via the reference voltage terminal 15 supplied with V _2, and outputs a second comparison signal F value of the amplified pulse signal D is high level when it reaches the second reference voltage V _2.

The output terminals of the first and second operational amplifiers 12 and 13 have first and second one-shot multivibrators 16.
17 are connected to each other, and become the high state when receiving the first and second comparison signals E and F in the high state.
Are output.

The first and second one-shot multivibrators 16 and 17 have a main control section constituted by a microcomputer.
The main control unit 18 has a memory 19 connected thereto.
And the display 7 are connected. The memory 19, the first group 20 and the temperature value for the parameter P ₃ the parameter consists of the instantaneous value for the parameter P ₁ and the integrated value for the parameter P _2, the parameter for the pressure values P ₄ and various parameters P ₅
And stored in a second group 21 consisting of

The main control unit 18 reads out the parameters of the first group 20 by receiving the first pulse signal G, and sequentially reads out the instantaneous value parameters P as shown in FIG.
₁ and the integrated value parameter P ₂ are displayed on the display 7,
When the second pulse signal H is input, the parameters of the second group 21 are read out, and the temperature value parameter P ₃ and the pressure value parameter P ₄ are sequentially read as shown in FIG.
And various parameters P ₅ are displayed on the display 7.

In this embodiment, the first and second operational amplifiers 12 and 13, the first and second one-shot multivibrators 16 and 17, and the main control unit 18 constitute a selection signal generating circuit. The first and second pulse signals G and H constitute a selection signal. As will be described later, a signal whose polarity changes alternately is output from the pair of terminals 10a and 10b of the Hall element 10 by the N and S poles of the permanent magnet 3 with respect to the Hall element 10. The signal constitutes the input signal.

In the display switching device configured as described above, when the parameters of the first group 20 are to be displayed, the reed switch 2 and the Hall element 10 are controlled by the 3 is set. Then, a positive polarity amplified pulse signal D (for example, d ₁ ) is output from the Hall element side operational amplifier 11, and when the value reaches the first reference voltage V ₁ or more, the first comparison signal E in the high state. Is output from the first operational amplifier 12, and the first
From the one-shot multivibrator 4 to the main control unit
The first pulse signal G in the high state is input to 18.

The main controller 18 reads the parameters of the first group 20 from the memory 19 by inputting the first pulse signal G in the high state, and reads the instantaneous value parameters P of the first group 20. ₁ will be displayed on the display 7. Subsequently, when the integrated value parameter P ₂ is displayed, the permanent magnet 3 is separated from the reed switch 2 and the reed switch 2 is turned off, and then the permanent magnet 3 is arranged so as to have the same polarity as above. , The first operational amplifier 12 outputs the first comparison signal E in a high state. Then
The main control unit 18 will be displayed on the second display device 7 the integrated value for the parameter P ₂ is a parameter of the first group 20 following the instantaneous value for the parameter P _1.

When the parameters of the second group 21 are to be displayed, the position of the permanent magnet 3 is set so that the reed switch 2 and the Hall element 10 are affected by the N pole of the permanent magnet 3. Then, a negative-polarity amplified pulse signal D (for example, d ₂ ) is output from the Hall element-side operational amplifier 11, and when the value reaches the second reference voltage V ₂ or less, the second comparison signal F in a high state. Is the second operational amplifier 13
, The high-level second pulse signal H is input from the second one-shot multivibrator 4 to the main controller 18.

The main controller 18 reads the parameters of the second group 21 from the memory 19 by inputting the second pulse signal H in the high state, and reads the first temperature value of the second group 21. The parameter P ₃ is displayed on the display 7. Subsequently, when displaying the pressure value parameter P ₄ , the permanent magnet 3 is separated from the reed switch 2 and the reed switch 2 is turned off, and then the permanent magnet 3 is arranged so as to have the same polarity as above, Second operational amplifier
13 outputs the second comparison signal F in a high state. Then, the main control unit 18 will be displayed on the second display device 7 the pressure value for the parameter P _4, which is a parameter of the second group 21 following the temperature value for the parameter P _3. Hereinafter, the third various parameters P ₅ of the second group 21 will be displayed on the display unit 7 in the same manner.

As described above, a signal (input signal) whose polarity changes alternately by the different poles of the permanent magnet 3 with respect to the Hall element 10 is generated, and the first one-shot in the subsequent stage of the first operational amplifier 12 is generated. From multivibrator 16
The first pulse signal G and the second pulse from the second one-shot multivibrator 17 after the second operational amplifier 13 are output.
The main control unit 18 selects the group 20 or 21 corresponding to the first and second pulse signals G and H based on the input from one of the pulse signals H , and selects the selected group. Are sequentially displayed, so that the display of desired parameters can be achieved more quickly than in the related art in which all the parameters stored in the memory are sequentially displayed. In addition, since quick display of desired parameters is achieved based on the polarity determination of the input signal,
There is no need to provide a complicated mechanism, and the configuration becomes simple.

In the above embodiment, the reed switch 2
FIG. 6 shows an example in which the permanent magnets 3 are arranged so that the N and S poles are orthogonal to the arrangement direction of the Hall elements 10.
As shown in (1), the reed switch 2 and the Hall element 10 may be arranged in parallel, and the permanent magnets 3 may be arranged so that the N and S poles are parallel in this parallel direction.

In the above embodiment, the display is switched by the operation of the Hall element 10 on condition that the reed switch 2 is turned on.
The switching of the display by the on / off operation causes poor contact, chattering, and the like. As a result, a malfunction may occur. No more.

In the above embodiment, since the reed switch 2 is provided, the current supply to the Hall element 10 is performed only at the time of display switching, so that the power consumption of the Hall element 10 and the entire circuit can be reduced. .

Further, in the above embodiment, the N and S poles of the permanent magnet 3 act on one Hall element 10, so that the reed switch 2 performed by the reed switch 2 of the conventional display switching device is reed switch. Since two or two functions are performed (this is shown by two switches m in FIG. 2), the configuration is not complicated to increase the display switching function.

In the flow meter, an explosion-proof structure is required depending on the application place and the like. Accordingly, a push switch or the like may not be used in the display switching device used in the flow meter. In the display switching device of the above, the switches used are the reed switch 2 and the Hall element 10, and even when an explosion-proof structure is required,
It can be applied appropriately.

Although the permanent magnet 3 is used in the above embodiment, it goes without saying that another magnetic field generating means such as an electromagnet may be used instead of the permanent magnet 3.

In the above embodiment, the case where one Hall element 10 is provided and the display is switched by one bit is taken as an example. However, the Hall element 10, the Hall element side operational amplifier 11, the first, A circuit comprising second operational amplifiers 12, 13 and first and second one-shot multivibrators 16, 17, etc.
A circuit 31 having the same configuration as 30 may be connected to the main control unit 18 as shown in FIG. 7 so that the display is switched by two bits. With this configuration, various types of groups or parameters can be read from the memory 19, and desired parameters can be displayed more quickly than in the above-described embodiment. In addition,
Similarly, by providing a plurality of circuits 31, a multi-bit display can be switched so that desired parameters can be displayed more quickly.

[0026]

Since the present invention is a display switching device configured as described above, the selection signal generation circuit determines the polarity of an input signal whose polarity changes alternately, and determines the result of the determination. Multiple parameters are stored based on
By generating a plurality of different selection signals for selecting a group to be selected, a group corresponding to the selection signal can be selected from the memory and the parameters included in the group can be displayed on the display means. The display of desired parameters can be speeded up as compared with the sequential display of In addition, since the desired parameter is quickly displayed based on the polarity determination of the input signal, a complicated mechanism is not required, and the configuration is simplified.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a display switching device according to one embodiment of the present invention.

FIG. 2 is a block diagram schematically showing functions of the display switching device.

FIG. 3 is a waveform diagram of a signal generated in each section of the display switching device.

FIG. 4 is a diagram showing a display order of parameters displayed by a first pulse signal of the display switching device.

FIG. 5 is a diagram showing a display order of parameters displayed by a second pulse signal of the display switching device.

FIG. 6 is a diagram showing an example in which the arrangement of a reed switch, a hall element, and a permanent magnet is changed in the display switching device.

FIG. 7 is a circuit diagram showing a display switching device according to another embodiment of the present invention.

FIG. 8 is a circuit diagram showing an example of a conventional display switching device.

FIG. 9 is a block diagram schematically showing functions of the display switching device.

FIG. 10 is a waveform diagram of a signal generated in each section of the display switching device.

FIG. 11 is a diagram showing a parameter display order of the display switching device.

[Explanation of symbols]

7 Display 12 First operational amplifier 13 Second operational amplifier 16 First one-shot multivibrator 17 Second one-shot multivibrator 18 Main controller 19 Memory 20 First group 21 Second group G First Pulse signal H second pulse signal P ₁ parameter for instantaneous value P ₂ parameter for integrated value P ₃ parameter for temperature value P ₄ parameter for pressure value P ₅ various data parameters

Claims (1)

(57) [Claims] 1. A method for dividing a plurality of parameters into a plurality of groups.
A memory for storing and split, and a control means for displaying on the display means the parameter is read from the memory, the control means discriminates the polarity of the input signal, based on the determination result, the parameter A selection signal generating circuit for generating a plurality of different selection signals for selecting the group in which the group is stored .