JPH1172392A - Temperature detector and heating control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a temperature detector in which a temperature detection voltage and a detection voltage by operating a switch are transmitted by an identical signal line. SOLUTION: ON-OFF switches SW1, SW2, SW3, SW4, SW5 act as temperature regulating switches which are turned on and off by a dynamic operation. Then, an output selection circuit is formed in such a way that diodes D1, D2 and resistances R1, R2, R3, R4, R5 are connected across a first terminal 11 and a second terminal 12, that, when a current flows into from the first terminal 11, a temperature detection voltage by a thermistor 13 is generated across the first terminal 11 and the second terminal 12 and that, when a current flows in from the second terminal 12, an ON-OFF voltage by the temperature regulating switches is generated across the first terminal 11 and the second terminal 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature detector provided with a temperature adjustment switch and a temperature control switch, and a heating control system.

[0002]

2. Description of the Related Art In recent years, in large-scale facilities such as schools, a cooling and heating control system in which a plurality of cooling and heating facilities are controlled by one control panel has become widespread.

In such a cooling / heating control system, a temperature detector provided with a temperature adjustment switch is widely used. In such a temperature detector, the temperature detection voltage and the switch operation detection voltage are transmitted to the control panel through separate signal lines.
When a temperature detector is provided in a room, the wiring work is troublesome and the wiring becomes conspicuous, thus deteriorating the scenery in the room.

[0004]

In the above-described conventional temperature detector provided with a temperature adjustment switch, the temperature detection voltage and the switch operation detection voltage are transmitted to the control panel through separate signal lines. When a container is installed in a room, the wiring work is troublesome, and the wiring becomes conspicuous, which deteriorates the scenery in the room.

An object of the present invention is to eliminate the above problems and to provide a temperature detector and a heating control system capable of transmitting a temperature detection voltage and a switch operation detection voltage on the same signal line.

[0006]

The temperature detector according to the present invention comprises:
A first and a second terminal, a thermistor for detecting a temperature, a temperature control switch for turning on and off by a mechanical operation, and a current switch connected between the first and the second terminals; When a current flows, a temperature detection voltage by the thermistor is generated between the first and second terminals, and when a current flows from a second terminal, the on / off voltage by the temperature adjustment switch is changed to the first and second terminals. And an output selection circuit for generating between two terminals.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a first embodiment of a temperature detector according to the present invention.

In FIG. 1, a temperature detector 10 includes first and second terminals 11 and 12, a plurality of resistors R1, R2, R3, R4 and R5 having different resistance values, and a plurality of resistors connected in series. On / off switches SW1, SW2, SW3, SW connected in parallel with each other
4, SW5 and the plurality of on / off switches SW1,
SW2, SW3, SW4, and SW5 are connected in series to the parallel connection, and only the current flowing from the first terminal to the second terminal is the plurality of on / off switches SW1, SW2, and SW5.
3, the first to make it flow through the parallel connection of SW4 and SW5
A thermistor 13 for detecting the temperature by changing the resistance according to the temperature; a resistor R0 connected in parallel to the thermistor 13; a resistor R0 connected in series to the thermistor 13; And a second diode D2 that allows only the current flowing from the first terminal 11 to the thermistor 13 to flow therethrough.

Hereinafter, the temperature detector 10 will be described in detail. The first and second terminals 11 and 12 are connected to a control device described later via wirings 1 and 2, respectively.

The first terminal 11 is connected to a diode D1.
ON / OFF switch S via the anode / cathode path of
It is connected to one terminal of W1, SW2, SW3, SW4, SW5. ON / OFF switch SW1, SW2, SW
3, SW4, and SW5 are connected to respective resistors R
1, R2, R3, R4, and R5 are connected to the second terminal 12. ON / OFF switch SW1, SW2, SW
3, SW4 and SW5 are respectively +2, +1,
It is turned on by pressing the temperature adjustment keys 0, -1 and -2. The second terminal 12 is connected to the first terminal 11 via the thermistor 13 and the anode-cathode path of the diode D2. The resistor R0 is connected to the thermistor 13 in parallel.

With this connection, the on / off switches SW1, SW2, SW3, SW4, and SW5 become temperature control switches that are turned on and off by a mechanical operation, and diodes D1 and D2 and resistors R1, R2, R3, and R4 are provided. , R
5 is connected between the first and second terminals 11 and 12,
When a current flows from the first terminal 11, the temperature detection voltage of the thermistor 13 is changed to the first and second terminals 11,
12 and an output selection circuit for generating an on / off voltage by the temperature control switch between the first and second terminals 11 and 12 when a current flows from the second terminal 12. I have.

FIG. 2 is a block diagram showing a control device connected to the temperature detector 10 of FIG.

In FIG. 2, reference numeral 20 denotes the temperature detector 10.
The first and second terminals 21 and 22 of the control device 20 are connected to the first and second terminals 11 and 12 of the temperature detector 10 via wires 1 and 2, respectively. You.

Hereinafter, the control device 20 will be described in detail.

The control device 20 includes a first terminal 2 and a second terminal 2.
1, 22, a switch circuit 23, a constant current circuit 24,
It comprises a differential amplifier 25, an analog / digital conversion circuit (hereinafter referred to as an A / D conversion circuit) 26, and a microcomputer 27.

The switch circuit 23 includes first to fourth switches SW11, SW12, SW13, and SW14.

The first terminal 21 of the control device 20 is connected to one ends of the switches SW11 and SW14 of the switch circuit 23. The second terminal 22 of the control device 20 is connected to one ends of the switches SW12 and SW13 of the switch circuit 23.
The other ends of the switches SW13 and SW14 are connected to a constant current circuit 24.
Of the differential amplifier 25
Is connected to the non-inverting input terminal (+). Switch SW1
3. The other end of the switch 14 is connected to the negative output terminal of the constant current circuit 24 and to the inverting input terminal (-) of the differential amplifier 25. The output terminal of the differential amplifier 25 is A
/ D conversion circuit 26 is connected to the input terminal. An output terminal of the A / D conversion circuit 26 is connected to an input terminal of the microcomputer 27. The microcomputer 27 performs the switching control of the switch circuit 23 to convert the digital signal a1 obtained by the A / D conversion circuit 26 into the on / off switches SW1, SW2, SW3, SW4, and SW4 of FIG.
SW5 ON / OFF detection and thermistor 1
3 recognizes the temperature detection voltage.

The operation of the temperature detector 10 and the control device 20 shown in FIGS. 1 and 2 will be described.

The control device 20 shown in FIG. 2 uses the switch SW shown in FIG.
When detecting on / off of 1, SW2, SW3, SW4 and SW5, the microcomputer 27 turns on the switches SW11 and SW13 of the switch circuit 23 and turns off the switches SW12 and SW14. Thus, the constant current (I) is supplied from the constant current circuit 24 to the first input terminal of the temperature detector 10 via the switch SW11, the terminal 21, and the wiring 1.
1) flows in. In this case, no current flows through the thermistor 13 due to the action of the diode D2, and the switches SW1 and
Of the switches SW2, SW3, SW4, and SW5, current flows only in the switch that is turned on. Therefore, the inverting input terminal (−) and the non-inverting input terminal (+) of the differential amplifier 25
Among the 1, R2, R3, R4, and R5, a voltage generated by a resistor connected in series to the ON switch is applied. The output subjected to differential amplification by the differential amplifier 25 is A / D converted by an A / D conversion circuit 26 and recognized by a microcomputer 27. Thereby, the microcomputer 27 switches the switches SW1, SW2, SW3, SW
4, SW5 on / off can be recognized.

When the control device 20 shown in FIG. 2 detects recognition of the temperature detection voltage by the thermistor 13, the microcomputer 27 operates the switch SW1 of the switch circuit 23.
1, SW13 are turned off, and switches SW12, SW14 are turned on. As a result, the switch S
A constant current (I2) flows into the second input terminal of the temperature detector 10 via W12, the terminal 22, and the wiring 2. in this case,
By the operation of the diode D1, the switches SW1, SW
No current flows through SW2, SW3, SW4, and SW5, and current flows through the thermistor 13. Therefore, a voltage generated by the parallel connection of the thermistor 13 and the resistor R0 is applied to the inverting input terminal (−) and the non-inverting input terminal (+) of the differential amplifier 25. The output of the differential amplifier 25 is supplied to an A / D conversion circuit 26.
A / D converted by the microcomputer 27 and recognized by the microcomputer 27. Thereby, the microcomputer 27
Can recognize the temperature detection voltage by the thermistor 13.

Here, the switching of the switch circuit 23 has a period that is somewhat shorter than the time during which a human turns on the key.

In this case, an example of a specific operation of the thermistor 13 will be described. In the parallel connection of the thermistor 13 and the resistor R0, the resistance is 12.5 kΩ at 20 ° C., and the temperature change rate of the resistance is 0.25 kΩ / degree. It is configured so that Here, assuming that I2 is, for example, 0.2 mA, the thermistor 13
Is 2.5V. On the other hand, resistors R1, R2,
The resistance values of R3, R4, and R5 are set to 5 kΩ and 10 k, respectively.
When Ω, 15 kΩ, 20 kΩ, and 25 kΩ are set and I1 is, for example, 0.2 mA, the switches SW1, SW2, S
The detection voltages when W3, SW4, and SW5 are pressed are 1V, 2V, 3V, 4V, and 5V, respectively, and it is possible to determine which switch has been pressed.

According to such an embodiment of the present invention, the temperature detection voltage and the switch operation detection voltage can be transmitted through the same signal line, so that the wiring work is not troublesome and the wiring is outstanding. Can be eliminated.

FIGS. 3 to 5 are a front view, a side view, and a rear view, respectively, showing the appearance of the temperature detector 10 shown in FIG.

In FIG. 3, the temperature detector 10 is such that the circuit shown in FIG. The case 31 is adapted to be attached to a wall.

A plurality of slits 32 and 33 for passing air for temperature detection by the thermistor 13 shown in FIG. Case 31
The on / off switches SW1 and SW of FIG.
2, temperature control keys 41, 42, 43, 44, and 45 for turning on SW3, SW4, and SW5, respectively.

In FIG. 4, before each of the temperature control keys 41, 42, 43, 44 and 45 of the case 31,
Numerical values of +2, +1, 0, -1, and -2 indicating temperature shift are described.

In FIG. 5, on the back side of the case 31,
The terminals 11 and 12 shown in FIG. 1 are provided.

FIG. 6 is a block diagram showing a case where the temperature detector 10 and the control device 20 shown in FIGS. 1 to 5 are applied to a school gas heating management system.

The gas heating management system 5 is a heating control system, and includes a flow monitoring panel 51, a gas leak detector 52, a motor valve 53, a gas temperature control panel 54, a gas temperature sensor 55, and a gas meter disposed in a gas meter room 50. 5
6, 57, 58, 59, a gas boiler 61 of a boiler system B disposed in a lunch room 60, a gas boiler 63 of a gymnasium system D disposed in an indoor gym 62, and a centralized monitoring operation panel disposed in a staff room 64 65, a gas temperature control panel 67 arranged in a classroom 66, a gas heater 68 and a room thermo 69 of a heating system A, a gas heater 71 of a heating system A arranged in a science classroom 70, and a gas of a general system C It comprises a monitoring cock 72 for the pipe and a room thermo 73.

The gas meters 56, 57, 58, and 59 detect the flow rates of the gas in the gas pipes of the heating system A, the boiler system B, the general system C, and the gymnasium system D, respectively.

The temperature detector 10 shown in FIG.
9 and 73, and the control device 20 of FIG. 2 is applied to a gas temperature control panel 67.

Centralized operation panel 65 and gas temperature control panel 6
Reference numeral 7 controls the heater based on the temperature detection voltage obtained by alternately flowing current to the first and second terminals of the temperature detectors (room thermos 69 and 73) and the switch operation detection voltage. It is a control device.

With such a configuration, the temperature detector 10 and the control device 20 shown in FIGS. 1 to 5 can be applied to a school gas heating management system.

FIG. 7 is a circuit diagram showing a second embodiment of the temperature detector according to the present invention. The same components as those in the embodiment of FIG. I have.

In FIG. 7, the temperature detector 80 has the second
Is directly connected to the first terminal 11 via a parallel connection of the thermistor 13 and the resistor R0. in this case,
The resistance values of the resistors R1, R2, R3, R4, and R5 are sufficiently smaller than the lowest resistance of the thermistor 13, for example, 1/1.
Set to about 0.

The operation of the embodiment of the present invention will be described. In this description, the control device 20 shown in FIG. 2 is used as a substitute.

The control device 20 shown in FIG.
When detecting ON / OFF of SW1, SW2, SW3, SW4, and SW5, a constant current (I1) flows into the first input terminal of the temperature detector 10 via the wiring 1. In this case, the thermistor 13 and the switches SW1, SW2, SW3, SW
4 and SW5, the current flows only in the switch that is turned on.
For this reason, the inverting input terminal (-) and the non-inverting input terminal (+) of the differential amplifier 25 have resistors R1, R2, R3, R4,
Among R5, the voltage generated by the parallel connection of the resistor connected in series with the turned-on switch and the thermistor 13 and the resistor R0 is applied. The output of the differential amplifier 25 is A / D-converted by an A / D conversion circuit 26, and a microcomputer 27
Is recognized by Thereby, the microcomputer 27 switches the switches SW1, SW2, SW3, SW4, S
The on / off state of W5 can be recognized. In this case, R1, R
Since the resistance values of R2, R3, R4, and R5 are sufficiently smaller than the minimum resistance of the thermistor 13, the resistance change due to the temperature change of the thermistor 13 is small, and sufficient accuracy can be obtained.

When the control device 20 shown in FIG. 2 detects the recognition of the temperature detection voltage by the thermistor 13, the switch SW1, SW2, SW3, and SW3 are operated by the action of the diode D1.
No current flows through SW4 and SW5, and a current flows through the thermistor 13. Therefore, a voltage generated by the parallel connection of the thermistor 13 and the resistor R0 is applied to the inverting input terminal (−) and the non-inverting input terminal (+) of the differential amplifier 25. The output of the differential amplifier 25 is A / D-converted by an A / D conversion circuit 26.
It is converted and recognized by the microcomputer 27. Thereby, the microcomputer 27 can recognize the temperature detection voltage by the thermistor 13.

According to the embodiment of the invention, the same effects as those of the embodiment of the invention shown in FIG. 1 can be obtained, one diode can be reduced, the manufacturing cost can be reduced, and the temperature of the thermistor 13 When the detection of the detection voltage is performed, the current from the thermistor 13 flows directly to the first terminal 11, so that there is no influence of the forward drop voltage of the diode, and the accuracy of temperature detection can be improved.

FIG. 8 is a circuit diagram showing a third embodiment of the temperature detector according to the present invention. The same components as those in the embodiment of FIG. I have.

In FIG. 8, in the temperature detector 90, the other terminal of the on / off switch SW3 is not connected at all, and the resistor R3 shown in FIG. 1 is not provided. In this case, since the on / off switch SW3 is a switch having a temperature shift amount of 0, it can be considered that all the switches are turned off. In this state, the voltage value due to the parallel connection of the thermistor 13 and the resistor R0 is detected. That is, this state can be determined.

According to such an embodiment of the invention, the same effects as those of the embodiment of the invention shown in FIG. 1 can be obtained, and the manufacturing cost can be reduced by reducing one resistor.

The gas heating management system shown in FIG.
To the temperature detector and the control device shown in FIG.
The temperature detector shown in FIGS. 7 and 8 may be applied. Further, the embodiments of the invention shown in FIGS. 1 to 8 can be variously applied to a cooling and heating system other than a school gas heating management system.

[0046]

According to the present invention, the temperature detection voltage and the switch operation detection voltage can be transmitted through the same signal line, so that wiring work is not required and wiring is not noticeable. it can.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a temperature detector according to the present invention.

FIG. 2 is a block diagram showing a control device connected to the temperature detector shown in FIG. 1;

FIG. 3 is a front view showing the appearance of the temperature detector of FIG. 1;

FIG. 4 is a side view showing the appearance of the temperature detector shown in FIG. 1;

FIG. 5 is a rear view showing the appearance of the temperature detector of FIG. 1;

FIG. 6 is a block diagram showing a case where the temperature detector and the control device shown in FIGS. 1 to 5 are applied to a school gas heating management system.

FIG. 7 is a circuit diagram showing a second embodiment of the temperature detector according to the present invention.

FIG. 8 is a circuit diagram showing a third embodiment of the temperature detector according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Temperature detector 11, 12 First and second terminal 13 Thermistor D1, D2 Diode R1, R2, R3, R4, R5 Resistance SW1, SW2, SW3, SW4, SW5 Switch

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 22, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 3

FIG. 2

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG. 8

Claims (6)

[Claims] 1. A first and second terminal, a thermistor for detecting temperature, a temperature control switch that is turned on / off by a mechanical operation, and a first terminal connected between the first and second terminals. A temperature detection voltage generated by the thermistor is generated between a first terminal and a second terminal when a current flows from a first terminal, and an on / off voltage generated by the temperature adjustment switch when a current flows from a second terminal. And an output selection circuit for generating between the first and second terminals. 2. A plurality of first and second terminals, a plurality of resistors having different resistance values, a plurality of on / off switches connected in parallel with each other in a state where the plurality of resistors are connected in series, A first diode connected in series to the parallel connection of the plurality of on / off switches, so that only a current flowing from the first terminal to the second terminal flows through the parallel connection of the plurality of on / off switches; A thermistor for detecting a temperature; and a second diode connected in series to the thermistor and allowing only a current flowing from the second terminal to the first terminal to flow through the thermistor. Temperature detector. 3. A first and a second terminal, a plurality of resistors having different resistance values from each other, a plurality of on / off switches connected in parallel with each other in a state where the plurality of resistors are connected in series, A first diode connected in series to the parallel connection of the plurality of on / off switches, so that only a current flowing from the first terminal to the second terminal flows through the parallel connection of the plurality of on / off switches; And a thermistor connected between the first and second terminals. 4. A first and second terminal, a plurality of resistors having different resistance values, and a plurality of temperature shift on / off switches connected in parallel with each other in a state where the plurality of resistors are connected in series. A first connection in series with the parallel connection of the plurality of on / off switches so that only a current flowing from the first terminal to the second terminal flows through the parallel connection of the plurality of on / off switches. A diode, a temperature change 0 degree selection switch connected only at one end to the parallel connection of the plurality of on / off switches, and a thermistor connected between the first and second terminals. And temperature detector. 5. The temperature detector according to claim 1, wherein a resistor is connected to the thermistor in parallel. 6. A heater, a temperature detector according to any one of claims 1 to 5, and a temperature detector obtained by alternately supplying current to first and second terminals of the temperature detector. A control device for controlling the heater based on a temperature detection voltage and a switch operation detection voltage, the heating control system comprising: