JPS5945926B2 - temperature measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature measuring device that converts detected temperature into a digital value.

In recent years, air conditioner control devices have come to use electronic components with arithmetic functions such as microcomputers, which are combined with A-D converters to measure room temperature and convert the measured value and set value. In comparison, it controls the operation of compressor motors, fan motors, etc., and displays measured values on displays.

This FHL leg device is designed to ensure that the room temperature setting is within the specified range.
Therefore, the room temperature to be measured only needs to be within this predetermined range, and it would be wasteful to use an expensive A-D converter that can measure a wide range, such as a commercially available A-D converter. Ta.

In addition, conventional A-D converters input the detected temperature as an analog voltage value via a sensor, convert this into a time signal, count the number of pulses generated within this time, and convert it into a digital signal. Since this method converts into measured values, it has the disadvantage that measured values tend to fluctuate as the power supply voltage fluctuates. 5 The present invention was developed in view of the above facts.

It is an object of the present invention to provide a temperature measuring device which generates digital outputs in multiple stages when a detected temperature is within a predetermined range, has an inexpensive circuit configuration, and is extremely unaffected by voltage fluctuations. 0 Hereinafter, one embodiment of the present invention will be described by applying it to an air conditioner control device using a microcomputer.

In FIG. 1, reference numeral 1 denotes a microcomputer, and the microcomputer has a power terminal B connected to a DC power source 2, and has human power ports 11 to 6 and output ports P1 to PIO.

Reference numeral 3 denotes a reference voltage setting device, and this setting device includes Sawata resistors 5 and 6 and resistors T and 8 connected in parallel between the DC power supply 2 and the ground 4.
The connection point 9 of each series circuit 0 is
and 10 are connected to human power ports 11 and 12, respectively.

11 is a linear amplifier, which includes resistors 13 and 14 connected in parallel between DC power supply 2 and ground 12, and resistor 1.
A temperature sensor IT such as a negative characteristic thermistor for detecting the room temperature 5 connected in parallel to the series circuits 5 and 16 and the resistor 14
, an operational amplifier 23 having a comparison terminal 20 and a reference terminal 21 connected to connection points 18 and 19 of each series circuit, and an output terminal 22 connected to the input port 13, and an output terminal 22 and a reference terminal of the operational amplifier 23. 21 and a feedback resistor 24 connected between them.

25 is an operation setting circuit. The circuit includes an operation key 26,
It has an up key 27 and a down key 28, one side of each key is connected to the DC power supply 2, and the other side is connected to the manual ports 14 to 16, respectively.

Reference numeral 29 denotes a set temperature indicator, which is composed of a plurality of light emitting elements and a decoder device, and receives a latch signal from the output port P1 and a binary 4 signal from the output ports P3 to P6.
The pit data signal is supplied.

Reference numeral 30 denotes a room temperature indicator, which is composed of a plurality of light emitting elements, a decoder device, and a driver, and is supplied with a latch signal from output port P2 and a data signal from output ports P3 to P6.

Reference numeral 31 denotes a control relay circuit, which includes a control relay 32 for controlling start/stop of a compressor motor (not shown) and a control relay 33 for controlling air volume of a fan motor (not shown).
35, one side of each relay is connected to the DC power supply 2, and the other side is a driver 36 having a reversing function.
are connected to output ports P7 to PlO, respectively.

FIG. 2 shows the internal system of the microcomputer 1.

Reference numeral 37 denotes a discriminating device, which sequentially and repeatedly checks the presence or absence of signals at the input ports 14 to 16 to determine the operation setting circuit 25.
Check key operations.

Reference numeral 38 denotes an operation control device, and when the operation of the operation key 26 is confirmed by the discrimination device 37, the discrimination output is inputted to the device, and the first discrimination output input causes the operation command, and the second discrimination output inputs the operation control device. A stop command is issued to the next-stage thermo device 39, and the process is repeated from the third time onwards.

40 is an addition/subtraction device, and this device is! F4J8l Gioki 3
At step 7, an addition command or a subtraction command is input every time the operation of the push key 27 or the down key 28 is confirmed.

Reference numeral 41 denotes a set temperature storage unit, which stores the set temperature data of 27°C as initial data by converting it into a binary value, and stores the stored value every time an addition command or a subtraction command is input to the addition/subtraction device 40. After being called by the device 40 and adding or subtracting a predetermined value, the temperature is transferred from 23°C to 31°C.
The set temperature is from [0, 0, 0, 1] to [1, 0, 0
, 1] are stored as binary data.

42 is a comparison device, which is an analog switch 43
45, a pulse generator 46, and a counter 47
The analog switches 43 to 45 sequentially close the circuit for short periods of time once every 10 seconds, and the reference voltage at the connection points 9 and 10 of the reference voltage setting device 3 is output from the manual ports 11 to 13. and the output voltage of the linear amplifier 11 are individually taken in.

Further, the pulse generator 46 generates the number of pulses proportional to the voltage difference between each input voltage and the voltage value of the DC power supply 2 as a reference. Furthermore, the calculation unit 48 calculates the number of pulses corresponding to each input voltage (the number of pulses when each analog switch is closed).
This is to calculate multiple stages of binary digital values by comparing them as described below. Reference numeral 49 denotes a room temperature storage section, which stores the digital value sent every 10 seconds from the calculation section 48 of the comparator 42 as new room temperature data when it differs from what has already been stored.

The thermo device 39 operates according to an operation command from the operation control device 38, and during operation, compares the set temperature in the storage device 41.49 with room temperature data,
A control signal of ``1'' or 0'' is issued from 7 or PIO to start/stop the compressor motor or fan motor and to control the air volume. 50 is a display signal generator;
Each data in the storage devices 41 and 49 is read, a set temperature display signal is output from output ports P3 to P6 along with a latch signal from output port P1, and a room temperature display signal is output from output port P3 along with a latch signal from output port P2. The light is emitted from P6 to P6, and this is repeated in order, causing the light emitting elements of each display 29, 30 to display in stages.

The microcomputer 1 is in an operating state unless a power switch (not shown) is turned off, and the discrimination device 37 and the comparison device 4 are operated based on a pre-stored program (not shown).
2 and the display signal generator 50 are always operated.

At this time, the DC power supply voltage is being supplied to the linear amplifier 11, and the resistance value of the room temperature sensor 17 changes depending on the room temperature, and the voltage at the connection point 18 between the resistors 13 and 14 changes accordingly. The characteristic of the output voltage X of the operational amplifier 23 with respect to the room temperature Tx is a straight line as shown in FIG. 3A. On the other hand, the same DC power? The reference voltage setter 3 to which voltage is supplied is connected to a resistor 5.
The voltage at connection point 9 determined by the resistance value of Similarly, the voltage at the connection point 10 is set to a value V, which is equal to the output voltage of the operational amplifier 23 at room temperature T2 (21.5° C.), as shown by the straight line in FIG. 3C. The microcomputer 1 then operates the analog switch 43 of the comparator 42.
45 are sequentially closed for a short period of time once every 10 seconds, so first, input port 1 is closed by closing analog switch 43.
1, the reference voltage V at the connection point 9 is applied to the pulse generator 46.
is supplied to

The pulse generator 46 receives the voltage V of the DC power supply 2 as shown in FIG. Since the number of pulses Nx is generated proportional to the input voltage based on the input voltage V when the analog switch 43 is closed. -V, N1 pulses are sent to the counter section 47. Then, by closing the analog switch 44, the reference voltage Vx at the connection point 10 is applied to the input port 12.
is supplied to the pulse generator 46 via the pulse generator 4
6 is the input voltage. -2, a pulse of N2VA is sent to the counter section 47. Next, the analog switch 45 is closed, and during this closing time, the output voltage Vx of the operational amplifier 23 is supplied from the input port 13 to the pulse generator 46, and the pulse generator 46 receives the input voltage V. -Nx pulses are sent to the counter section 47 for Vx. The calculation unit 48 calculates the number N of pulses counted by the counter unit 47 and sent sequentially.
, N2, Nx into equation (1), the previously mentioned T,, T2
The room temperature Tx is calculated once every 10 seconds using

Then, the room temperature Tx calculated by equation (2) is 37°C from 21.5°C.
．． When the temperature is within the range of 5℃, it is divided into 16 equal parts of 1℃ each, and 21
16 as shown in Table 1 as a measured value between ℃ and 37℃.
A binary digital signal of the stage is sent to room temperature storage 49 .

Also, when the room temperature is below 21.5°C or above 37.5°C, the range is 21.5°C to 22.5°C or 36°C, respectively.
It is converted into the same digital signal as 5° C. to 37.5° C. and sent to the storage device 49. The measured values of the comparator 42 sent to the storage device 49 in this way are stored as they are in the storage device 49 as room temperature data.

At this time, the display signal generator 50 alternately outputs the set temperature (23° C. to 31° C.) data of the storage device 41 and the room temperature data corresponding to the latest measured value of the storage device 49 as a display signal from the output ports P3 to P6. A common display signal is sent to the indicators 29 and 30 in synchronization with the latch signals of ports Pl and P2, but as shown in Table 2, when the room temperature is below 23°C and above 31°C. A1 ＾= meeting Then, if the storage device 41 stores data [0, 1, 0, 0] corresponding to a set temperature of 26°C, the display 29 receives the data ゛1 sent from the output port P1. When the latch signal of ``'' is input manually, the output ports P3 to P6 [0, 1, 0, 0
] is decoded and a lighting display as shown in FIG. 5a is performed.

Furthermore, if the data [1, 0, 0, 0] corresponding to a room temperature of 30° C. is stored in the storage device 49, the display 30 will display the data when the latch signal "1" sent from the output port P2 is input. [1,0,0,0] of output ports P3 to P6
The display signal is decoded and a lighting display as shown in FIG. 5b is performed. Now, when the air conditioner is in a stopped state and the microcomputer 1 is in an operating state, as shown in the flowchart shown in FIG.

-, the reference voltage V2 is taken into the input port 12 by N pulses corresponding to the input voltage V. -N compatible with V2
Two pulses take voltage X into input port 3 and input voltage. Nx pulses corresponding to - The set temperature and room temperature are displayed on cage indicators 29 and 30, respectively. Drive key 2 here
6 is operated (closed when pressed), the discrimination device 37 detects this, and the operation control device 38 issues an operation command to the thermo device 39 based on the discrimination output. The thermo device 39 calculates the difference between the room temperature data in the storage devices 49 and 41 and the set temperature data, and in this case, since the room temperature data is large, the output port P
Send a total of 1” signal to 7 or PIO. Control relay 3
Turn on 2 to 35. Therefore, the combrezzar motor operates, the fan motor operates with a strong air volume, and the air conditioner starts cooling operation. As a result, the room temperature gradually decreases, the measured value obtained by the comparison device 42 becomes smaller, and the room temperature data in the storage device 49 is rewritten accordingly, so that the display signal changes and the display 30 does not light up. As the signals disappear one after another from the right, the output port P8 to P1O signal changes, and the air volume of the fan motor decreases. As shown in FIG. 6, the room temperature data in the storage device 49 is displayed (measured) at a value of 28 when the room temperature is falling when the room temperature Tx is at a boundary value such as 27.5°C.
℃, and when the temperature is rising, it is included in the temperature range of 27℃. In this way, when the room temperature Tx slightly goes below 25.5°C, the thermo device 39 changes the room temperature data [0, 0
, 1, 1] is smaller than the set temperature data [0, 1, 0.0], an output of ``00'' is output to the output port P7, the compressor motor is stopped, and the cooling operation is suspended.
The display on the display 30 at this time is as shown in FIG.

Then, when the room temperature Tx begins to rise, the display 30 indicates 26°C.
The thermometer 39 starts displaying the room temperature T.
The 12 output is not output to the output port P7 until x slightly exceeds 26.5°C, and has a differential of 1°C.

That is, when the display 30 starts to display 27°C as shown in Fig. 8, the cooling operation is restarted and the room temperature is maintained at 25.5°C to 26.5°C, near the set temperature of 26°C. 30 performs display centered on 26°C. Since the direct comparison device 42 calculates and obtains the room temperature Tx every 10 seconds,
The display on the display 30 does not rapidly hunt left and right when Tx is at the boundary value of 25.5° C. or 26.5° C. In the temperature measuring device incorporated in the above-described embodiment, the set temperature used by the thermometer 39 is 23°C to 31°C, and the temperature displayed on the indicators 29 and 30 is 23°C (
(including temperatures below 23℃) to 31℃ (including temperatures above 31℃)
However, the comparator 42? The room temperature is measured using a binary standard of 21.5℃ to 37.5℃, and a 16-level digital signal is generated within this range. And 21.5
For temperatures below .degree. C. and above 37.5.degree. C., the minimum value and maximum value signals were commonly used; this is because the 4-bit microcomputer 1 was used.

For the above-mentioned set temperature, a room temperature of 21.5°C to 32.5°C was measured. A plurality of stages of digital signals may be emitted within this range. Even in this case, since the linear amplifier 11 and the reference voltage setter 3 commonly use the DC power supply 2, even if the power supply voltage fluctuates, each voltage increases or decreases proportionally. Therefore, 2 of the reference voltage setter 3
The two reference voltages are applied to the linear amplifier 11 for two values sandwiching a predetermined temperature range (21.5°C and 37.5°C in this example).
The output voltage is always equal to the output voltage generated by the sensor, so there is no risk of the measured value being distorted by voltage fluctuations. As described above, the present invention provides a linear amplifier that emits a linear output voltage x according to a detected temperature, and an output voltage Vx that is equal to the output voltage that the linear amplifier emits for two values sandwiching a predetermined temperature range of the detected temperature. A reference voltage setter that generates two reference voltages V, V2, and a power supply voltage that is connected to a common power source with this linear amplifier and reference voltage setter.

and a comparator for inputting the voltage of the voltage. The difference voltages of Since it has calculation means that compares the number of pulses and generates multiple stages of digital output, it is possible to perform highly accurate temperature measurements for detected temperatures within a predetermined temperature range, and to detect temperatures outside the range. Temperature can be roughly measured (for example, measured as binary values across a predetermined temperature range or upper and lower limits of a predetermined temperature range) to facilitate the design of linear amplifiers and to use inexpensive ones. It is particularly suitable for measuring room temperature in comparison with a set temperature in a predetermined range, such as in an air conditioner control device.・
Further, in the device of the present invention, the linear amplifier and the reference voltage setter are connected to a common DC power supply, so that even if there is a fluctuation in the power supply voltage, there is no fluctuation in the measured value. Furthermore, the comparator of the present invention replaces the two input reference voltages and the output voltage of the linear amplifier with the number of pulses corresponding to each voltage value and performs a comparison operation. but,
It can be configured with a microcomputer that can also be used as various control devices and display signal generation devices, and can have a simple configuration of a linear amplifier, a reference voltage setting device, and a microcomputer.

[Brief explanation of drawings]

The figures show an embodiment in which the device of the present invention is applied to a control device using a microcomputer for an air conditioner. A block diagram showing the internal system,
FIGS. 3 to 9 are explanatory diagrams of the operation of this apparatus, respectively. 1... Microcomputer, 2... DC power supply, 3
...Reference voltage setting diagram, 11...Linear amplifier, 42
...Comparison device, 46...Pulse generator, 48...
Arithmetic section.

Claims (1)

[Claims] 1. A linear amplifier that generates a linear output voltage V_X according to the detected temperature, and two reference voltages V_1 that are equal to the output voltage V_X that the linear amplifier generates for two values sandwiching a predetermined temperature range of the detected temperature. It is equipped with a reference voltage setter that emits V_2, and a comparator that is connected to a common power source with the linear amplifier and the reference voltage setter and inputs the power supply voltage V_0, and this comparator is configured to calculate V_X with respect to the voltage V_0,
A pulse generating means that takes each differential voltage of V_1 and V_2 as an input voltage and generates a number of pulses corresponding to the value of this voltage, and a pulse generating means that generates a number of pulses from this pulse generating means when the detected temperature is within the predetermined temperature range. 1. A temperature measuring device comprising: arithmetic means for comparing and generating digital outputs in a plurality of stages.