JP2584320Y2 - Digital switch - Google Patents

Description

[Detailed description of the invention] [Field of the invention] This invention is provided in various control devices such as an electronic temperature controller, for example, and sets various values such as a control set value of a control target and a target value to be controlled. Related to digital switches used when instructing mechanical devices
More specifically, the present invention relates to a digital switch provided with an operation switch for inputting and setting a predetermined set value to a control device and a display for displaying the set value on a front panel side. FIG. 6 is a block diagram showing a configuration example of a conventional digital switch. In FIG. 6, reference numeral 72 denotes a reversible preset counter, which inputs and sets a predetermined set value to the reversible preset counter 72. Operation switch 73 and a display 74 on which a predetermined set value input to the reversible preset counter 72 is displayed.
71 is provided. Reference numeral 75 denotes an electronic temperature controller as an example of an external control device, which is electrically connected to the digital switch 70, and includes an arithmetic processing circuit (hereinafter, referred to as a microcomputer) provided in the electronic temperature controller 75. CPU) 76
Is configured to read a predetermined set value input to the reversible preset counter 72 of the digital switch 70, in this example, a set temperature value at predetermined time intervals. A temperature control circuit 77 is connected to the CPU 76,
Heater 78 and temperature sensor connected to this temperature control circuit 77
79 is inserted inside the thermostat 80. In the above configuration, a predetermined set temperature value, for example, “30” is input and set to the reversible preset counter 72 by operating the operation switch 73. In this state, the electronic temperature controller 75
Is driven, the set temperature value “30” input to the reversible preset counter 72 is read by the CPU 76 at a predetermined time interval, and based on the read set temperature value “30”. The operation of the heater 78 is controlled so that the temperature control circuit 77 is driven and the difference from the temperature value detected by the temperature sensor 79 that detects the internal temperature of the constant temperature bath 80 becomes zero, and the internal temperature of the constant temperature bath 80 is reduced. The above set temperature value is automatically controlled to "30", that is, 30 ° C. As described above, in the conventional digital switch 70, the reversible preset counter 72 is
The control temperature of the electronic temperature controller 75 can be arbitrarily controlled by changing the set temperature numerical value input to and set in the electronic temperature controller 75. However, in the conventional digital switch, the counter 72
When it is desired to keep the set value secret, the display surface of the digital display 74 is covered with an opaque adhesive tape or the like. Therefore, every time the input set value of the reversible preset counter 72 is rewritten, an adhesive tape or the like must be re-applied, and the work associated with rewriting the set value is extremely troublesome. In addition to the operation of rewriting the input set value of the reversible preset counter 72, since the display operation of the display 74 is always continued, power for driving the display 74 is wasted. [Purpose of the Invention] The present invention has been made to solve the above-described problems, and has as its object to provide a digital switch that can easily rewrite an input set value of a reversible preset counter and that consumes less power. And [Configuration and Effect of the Invention] The digital switch according to the invention is configured separately from a controlled device incorporating an arithmetic processing circuit such as a temperature controller, and a control set value of a control target and a target value to be controlled. A digital switch for inputting and setting a predetermined set value such as a predetermined set value to the arithmetic processing circuit of the controlled device, and writes a previous set value stored in a built-in memory in the arithmetic processing circuit of the controlled device. A reversible preset counter capable of addition and subtraction, a pulse generating circuit for incrementing the reversible preset counter, and a set value of the reversible preset counter provided on the front plate side and added and subtracted through the pulse generation circuit to set a predetermined set value. An operation switch for writing to the reversible preset counter and an operation state for displaying the data output and operation state of the reversible preset counter A display, a display drive circuit for driving the operation status indicator according to the data output of the reversible preset counter, and a display operation of the display connected to an output stage of the display drive circuit by applying a display inhibit signal. A display prohibition circuit for stopping the reversible preset counter, reading the changed set value of the reversible preset counter into the arithmetic processing circuit, changing the previous set value, controlling the controlled device, and performing the display prohibition. The output of the circuit is controlled by a display-inhibiting operation switch provided on the front panel side, so that the display operation or stop of the display is performed. According to this invention, since the digital switch is configured separately from the controlled device, the digital switch is set at a desired location without being affected by the setting location of the controlled device, and the controlled device is controlled. A predetermined set value such as a control set value to be controlled by the device or a target value to be controlled can be input and set to the arithmetic processing circuit of the controlled device. Therefore, according to the above configuration, even if the controlled device is in an existing state, if the digital switch according to the present invention is connected to the controlled device, the digital switch is stored in the memory of the arithmetic processing circuit (CPU) of the controlled device. Since it is possible to input various data signals to the reversible preset counter, it is very easy to change the set value. Further, when it is desired to keep the set value of the counter confidential, the display operation and stop of the display can be achieved by the presence or absence of the application of the display prohibition signal, so that the display can be easily erased. Furthermore, the display operation of the display device may be achieved only at the time of rewriting the input set value of the reversible preset counter, so that the power consumption for driving the display device is reduced accordingly. In addition, the digital switch according to the present invention includes an input / output circuit for switching a data signal from an arithmetic processing circuit of the controlled device to an input / output state and a high resistance state, and a data signal from the arithmetic processing circuit to a reversible preset counter. It is recommended to include an input / output control circuit for applying a control signal for input to the input / output circuit, and a latch circuit for holding a part or all of the signal input to the reversible preset counter. [Description of Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional side view showing an example of a digital switch according to the present invention. In FIG.
Is a case, and a display window 3 provided with an optical filter is formed at the center of the front plate 2a of the case 2.
, The numerical value displayed on the digital display 4 can be visually recognized. 5 is an addition-side push button provided below the display window 3,
Reference numeral 6 denotes a subtraction-side push button provided above the display window 3, and mechanical switches 7, 8 are provided in correspondence with these push buttons 5, 6. 9, 10 is a printed wiring board, 11 is a connector,
Reference numeral 12 denotes an integrated circuit, and reference numeral 13 denotes a wrapping terminal. The wrapping terminal 13 is connected to the digital switch via the connection connector 11 and a CPU 35 of an external device described later. 14 is an operation status indicator. FIG. 2 is a block diagram showing a circuit configuration of the digital switch. In FIG. 2, reference numeral 15 denotes a reversible preset counter capable of addition and subtraction.
Are displayed on the digital display 4 and the operation state display 14, respectively. 16 is a display drive circuit for driving the digital display 4 and the operation state display 14, 17 is an input / output circuit for switching the signal line between input / output and high resistance states, and 18 is the reversible preset counter.
A pulse generation circuit for incrementing or decrementing 15 is provided, 19 is an input / output control circuit, 20 is a latch circuit for holding a part or all of the input signal, and 21 is a reset circuit. Reference numeral 22 denotes a display prohibition circuit interposed between the display drive circuit 16 and the digital display 4, and the display prohibition circuit 22 is formed of, for example, an AND gate circuit. FIG. 5 shows an example of the configuration of the display inhibition circuit 22.
In the figure, reference numeral 25 denotes an AND circuit, which receives a data signal a from the display drive circuit 16 and a display inhibit signal, for example, a blanking input signal b from the CPU 35 of the external device. The display inhibition signal b is applied to the AND circuit 24 by a mechanical switch 25 that is opened and closed by a pressing operation of the push button 23. The display-prohibiting push button 23 is set on the front panel 2a to open and close the mechanical switch 24. The digital switch 31 is configured to perform only one-digit digital display. As shown in FIG. 3, a plurality of such digital switches 31 are arranged so as to be connected to each other in the width direction. Numerical display of digits is performed. In FIG. 3, reference numeral 32 denotes a space unit for setting the interval between the adjacent digital switches 31, 31 to a predetermined value, and reference numerals 33, 34 denote end plates provided on the left and right. Next, the operation of the above configuration will be described. Now, in FIG. 2, the CPU 3
The data signal including the previous set value stored in the built-in memory in 5 is written to the reversible preset counter 15 via the input / output circuit 17, and further provided on the front panel 2a by driving the display drive circuit 16. The set numerical value is displayed on the digital display 4. The input / output circuit 17 is set in an input state by the chip select, write, and read input signals of the input / output control circuit 19, and the data signal of the input / output circuit 17 is input to the reversible preset counter 15 by the write signal. , Are written and held in the latch circuit 20. Further, these data signals are displayed on the digital display 4 by the display drive circuit 16. If the mechanical switch 24 is held open by pressing the push button 23 during the operation of the CPU 35 of the external device, the display prohibition signal b is not applied to the AND circuit 25 shown in FIG. By driving the display drive circuit 16, the set numerical value is displayed on the digital display 4 provided on the front panel 2a, and the operation state is driven and displayed on the state display 14. Now, when the push button 5 on the addition side is pressed, the mechanical switch 7 is turned on, and an addition command is issued to the pulse generation circuit 18.
This pulse generation circuit 18 causes the reversible preset counter 15 to perform an addition operation. Here, when the pressing operation time on the addition-side push button 5 is equal to or shorter than a predetermined time, the reversible preset counter 15 performs one addition operation, and
When the pressing operation time is continuous, the reversible preset counter 15 continuously performs the adding operation. Then, when the reversible preset counter 15 is added to 9 → 0, an added digit signal is output for the upper digit. In response to this, the upper digit pulse generation circuit 18 sequentially applies the data signal to the reversible preset counter 15 to perform the addition operation. On the other hand, when the push button 6 on the subtraction side is pressed,
When the mechanical switch 8 is turned on, a subtraction command is issued to the pulse generation circuit 18, and the pulse generation circuit 18 causes the reversible preset counter 15 to perform a subtraction operation. This subtraction operation is the same as the above-mentioned addition operation, and the above-mentioned reversible preset counter is used.
When the number 15 continues the subtraction operation and is subtracted from 0 to 9, a subtracted digit signal is output for the upper digit. When the push buttons 5 and 6 are simultaneously pressed, the signals from the mechanical switches 7 and 8 are applied to the reset circuit 21, and the reversible preset counter 15 is reset to zero. When the push buttons 5 and 6 continue to be pressed, a reset out signal is output from the reset circuit 21 to reset all digits of the reversible preset counter 15 to zero. The operation when the above digital switch 31 is connected to, for example, the electronic temperature controller 75 shown in FIG. 6 will be described. First, when the electronic temperature controller 75 is turned on,
From the CPU 35 (corresponding to the CPU 76 in FIG. 6) in FIG.
Temperature setting numerical value input in advance to U35, for example, "3
"0" is written to the reversible preset counter 15 and the set value "30" is displayed on the digital display 4. If the displayed set value is an appropriate value,
There is no need to press the push buttons 5 and 6, and the electronic temperature controller 75 is controlled so that the displayed temperature set value is obtained. When the set numerical value displayed on the digital display 4 is not an appropriate value, the push buttons 5 and 6 are pressed and operated.
What is necessary is just to change the set value of the reversible preset counter 15, and this changed set value is read by the CPU 35,
The electronic temperature controller 75 is controlled so as to have the set numerical value after the change. As described above, the reversible preset counter is used by the data stored in the internal memory of the CPU 35 of the external device.
Since the 15 set values can be rewritten, it is easy to change the set values. When it is desired to keep the set value of the reversible preset counter 15 secret, release the pressing of the push button 23 and release the mechanical switch 24.
Is closed, the display inhibit signal b is applied to the AND circuit 25 shown in FIG. Therefore, the data signal a from the display drive circuit 16 is not applied to the digital display 4 provided on the front panel 2a, and the set numerical value is not displayed. Thus, when it is desired to keep the set value of the counter 15 secret, the display can be easily erased. Moreover, the display operation of the display unit 4 only needs to be achieved during the rewriting operation of the input set value of the reversible preset counter 15, so that the power consumption for driving the display unit 4 is reduced accordingly. The push buttons 5 and 6 and the mechanical switches 7 and 8 in the above embodiment were used.
Alternatively, as shown in FIG. 4, a detection circuit 36 for detecting finger contact may be provided, and the contact portions 37 and 38 may be provided on the front plate 2a of the case 2. The other components of the block circuit of the touch-type digital switch are the same as those described with reference to FIG. 2, and a detailed description thereof will be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal side view of an example of a digital switch according to the present invention, FIG. 2 is a block diagram showing a circuit configuration of the digital switch, and FIG. FIG. 4 is a block diagram showing a circuit configuration of a digital switch according to another embodiment of the present invention, FIG. 5 is a block diagram showing an example of a display inhibition circuit, and FIG. 6 is an operation of a conventional digital switch. FIG. 3 is a schematic configuration diagram for explaining the configuration. 2a front panel, 4,14 display, 5, 6, 26 push button, 7, 8, 24 mechanical switch, 15 reversible preset counter, 16 display drive circuit, 17 input / output circuit, 18 pulse Generating circuit, 19: input / output control circuit, 20: latch circuit, 21: reset circuit, 22
... Display prohibition circuit, 35 ... CPU (calculation processing circuit of external equipment, etc.).

Claims (1)

(57) [Rules for requesting registration of utility model] A predetermined processing value such as a control set value of a control target or a target value to be controlled is configured separately from a controlled device incorporating a processing circuit such as a temperature controller, and the processing circuit of the controlled device is provided. A reversible preset counter capable of adding and subtracting a previous set value stored in a memory built in the arithmetic processing circuit of the controlled device, A pulse generating circuit for operating the reversible preset counter, an operation switch provided on the front panel, and adding and subtracting a set value of the reversible preset counter via the pulse generating circuit to write a predetermined set value to the reversible preset counter; An operating status indicator for displaying data output and operating status; and A display drive circuit driven in accordance with the data output of the display drive circuit; and a display prohibition circuit connected to an output stage of the display drive circuit and stopping a display operation of the display device by applying a display prohibition signal, wherein the reversible preset counter The arithmetic processing circuit reads the changed set value, changes the previous set value, controls the controlled device, and operates the display prohibition circuit on the front panel side for display prohibition. A digital switch characterized in that output is controlled by a switch so that display operation and stop of the display are performed. 2. An input / output circuit for switching a data signal from the arithmetic processing circuit of the controlled device to the input / output and high resistance states, and a control signal for inputting the data signal from the arithmetic processing circuit to the reversible preset counter. 2. The digital switch according to claim 1, further comprising: an input / output control circuit applied to an output circuit; and a latch circuit for holding a part or all of a signal input to the reversible preset counter.