JPS6046729B2 - temperature control device - Google Patents

Description

Detailed Description of the Invention The present invention detects the temperature of a controlled object controlled by a heat source for cooling or heating with a bridge including a thermistor, and turns on a comparator using this voltage. -・゛ ＾”ru, 100 days yF■1ctc゛sho1”n,
This relates to a temperature control device for controlling 47U3 and 10H.

The purpose of the group is: i) During the pulse period from the power reset circuit when the power is turned on, the bridge gap temperature is set to approximately zero, that is, near the set OFF temperature Y℃, and this temperature and the temperature of the controlled object are set. By comparing the heat source, it is possible to start operation quickly.

For example, in a conventional temperature control device, when a room is cooled by a compressor, if the room temperature of the room to be controlled is higher than the set ON temperature The compressor stops when the temperature drops to 'C, and the gap temperature a is constant, and a'C=
(X-Y)°C. Therefore, when the power is turned on, the setting is ON.
Although the operation is not started unless the room temperature is higher than the temperature X°C, the present invention is a temperature control device that changes the gap temperature to a set OFF temperature of Y°C or (Y+β)°C, where β<a. 2) With the output of the forced return timer that operates after a set time after the heat source stops operating, the temperature swing of the controlled object can be reduced by switching the bridge gap temperature to approximately zero or β℃ close to zero. Moreover, the heat source is often O.
This is a temperature control device that suppresses N and OFF.

Since the gap temperature a of the conventional temperature control device is constant, it has the following drawbacks when used for cooling temperature control using a compressor, for example.

As is well known, after the compressor stops operating, it cannot be restarted for several minutes until the refrigerant pressure is balanced due to the compressor motor locking, seizing, and tripping the power breaker, so the gap temperature a is a = 2.
It is set at around ℃. This a=2°C is determined because it takes several minutes for the temperature to rise by 2°C even when the indoor load is especially heavy, and the refrigerant pressure is balanced during this period.
However, when the indoor load becomes lighter, it takes more than ten minutes for a to rise by 2° C. after the compressor stops, and there is a drawback that the indoor humidity increases sharply within this period, making it uncomfortable. The present invention sets the set ON temperature as the set point of the bridge when the power is turned on, and sets the OFF temperature near Y℃ (the gap temperature is set to zero or β
a) By quickly starting operation and performing the above operation even after a set time has elapsed after operation has stopped, a safe and comfortable temperature control device is provided that eliminates the frequent turning on and off of the heat source. There is a particular thing.

An embodiment of the present invention will be described based on the drawings.

The drawing shows an example in which the present invention is applied to cooling using a compressor or heating using a heat pump. FIG. 1 is a diagram of the heat source system.

1 is a structure such as a house, 2 is a control room that is the object to be controlled, 3 is
is an outdoor unit, and is composed of a compressor 4, a four-way valve 5, an outdoor heat exchanger 6, a fan motor 7, and a capillary tube 8.

Reference numeral 9 denotes an indoor unit, which is composed of an indoor heat exchanger 10, a fan motor 11, a capillary tube 12, and piping 13,
At 14, the refrigerant is circulated.

During cooling, the four-way valve 5 operates so that the outdoor heat exchanger 6 functions as a condenser and the indoor heat exchanger 10 functions as an evaporator. Furthermore, during heating, the four-way valve 5 operates to circulate the refrigerant in the opposite direction. Note that 15 is blown air, 16 is suction air, and 17 is outdoor blown air. Figure 2 is an electrical wiring diagram. 18 is AC power supply, 19
1 is a power switch; 20 is a temperature control device; power terminals 21, 22; A relay 25 including a drive contact 25a for the temperature setting button 1, ream 2, and compressor 4, display sections 26, 27 for displaying the control status, cooling/heating selector switch 28,
29, and a terminal 31 that receives input from a switching means 30 that is turned on when heating is selected.

32 is a speed changeover switch for the fan motor 11 of the indoor unit.

FIG. 3 is a block diagram showing the main parts of the present invention, and the fourth
The figure is a timing chart for explaining this operation. Third
In the figure, a bridge 33 including a thermistor 23, and at least one comparator 3 which is turned 0N and 0FF by the bridge 33.
One is a differential circuit 35 which receives the output of the comparator 34 and determines the gap voltage of the bridge 33, and the 0 of the comparator.
A single time constant circuit 36 that is charged by the N output and starts discharging based on the generation of the 0FF output, detects the discharge pressure of the time constant circuit 36 and performs frequency division operation to generate multiple frequency divided outputs. A control logic 38 includes a counter type timer unit 37 that generates a signal, and operates the gate compressor 4 in a set order based on the output of the timer unit 37 and the output including the comparator 34, and a load output circuit 39 that operates the relay 25. , a power supply reset circuit 40 that emits a pulse only for a predetermined time after the AC power is turned on, and other input/outputs including a cooling/heating selector switch 29 and a display section 27. Further, 41 is a main circuit for temperature control. The operation sequence during cooling operation will be explained with reference to FIG. In this case, the cooling/heating selector switch 29 is OFF.
In Fig. 4, the temperature of the control room 2, that is, the room temperature, is 25°C ~
This is an example in which the temperature setting volume 24 is set to 27°C, and when the room temperature falls to the set OFF temperature Y°C = 25°C, the comparator 34 turns OFF and the load output circuit 39 turns off the relay 2.
5 is turned off, and the compressor 4 is stopped by its contact 25a. Also, when the room temperature rises to set ON temperature x °C = 2TC, the comparator 3
4 becomes 0N, the relay 25 becomes 0N, and the comparator 4 is activated. This state is mode A in FIG. Before explaining the operation when the power is turned on, an overview of the overall operation will be explained. In Fig. 4, when the room temperature falls to the set OFF temperature Y°C over time, the resistance of the thermistor 23 increases, so the voltage at the positive input terminal of the comparator 34 decreases, and the output of the comparator 34 becomes a "0" voltage, i.e. OFF and the compressor 4 stops.This also causes the differential circuit 35 to turn OFF, disconnecting the gap resistance 44 of the bridge 33, and setting the reference resistances 42 and 43 to 1.
Return to series circuit. As a result, the negative terminal of the comparator 34, that is, the reference voltage, is set higher than the voltage Vs when the compressor 4 is turned on by ΔV. In terms of temperature,
At the time Illjtl, the set point of the bridge 33 is Y°C
This means that there was a sharp transition from the temperature to X℃. Before time,
Since the room temperature is higher than the set OFF temperature Y° C., the output of the comparator 34 is “1” voltage, that is, 0N.
With this 0N output, the single time constant circuit 36 is charged to approximately the power supply voltage and is on standby. Then, at time 111t1, the room temperature drops to the set OFF temperature Y°C, so the comparator 34 turns OFF, and the capacitor 46 of the time constant circuit 36
is discharged through the resistor 47, and when this voltage drops to the set reference low voltage (2), the control logic 38 detects and outputs at the time h. This period T2 is a period in which restarting the compressor 4 is prohibited, and restarting is prohibited even if there is an 0N signal from the comparator 34 or even if the power switch 19 is turned off and then turned on again. control logic 38 to
is configured. In addition, only during this T2 period, the display section 2
7 lights up. Next, mode B in FIG. 4 will be explained.

This mode is used when the load on the control room 2 is light. When the room temperature drops to the set OFF temperature Y℃ after a certain period of time, the comparator 34 becomes 0.
FF and disconnect the gap resistor 44 of the bridge 33. As a result, the 0N point of the comparator 34 becomes the set ON temperature X° C., and the capacitor 46 of the time constant circuit 36 starts discharging. And the time taken for this voltage to drop to the reference low voltage V determined by the control logic 38! Then, the timer section 37 of the control logic 38 outputs an output, and the restart inhibition state for the compressor 4 is released. This period T2 is the same as mode A. After time T8, the time constant circuit 36 outputs the reference high voltage V
The control logic 38 is configured to generate a clock signal by charging and discharging between the reference low voltage VL and the reference low voltage VL. This final frequency divided output operates the differential circuit 35 and sets the gap resistor 44 of the bridge 33 to 0N.As a result, the resistors 43 and 44 are connected in parallel. bridge 3
The set point 3 falls from the set ON temperature X° C. to the new set ON temperature x′C (a temperature higher than the set OFF temperature Y° C. by the gap temperature β° C.). Hereinafter, the predetermined time T1 from the beginning to the end will be referred to as the forced return time. Note that the gap temperature β° C. is determined by the gap resistance 44 when the differential circuit 35 operates according to the final frequency-divided output of the control logic 38.
The differential circuit 35 is configured to include a dummy resistor Rx in series with the dummy resistor Rx, and is configured such that the dummy resistor Rx becomes zero when operated by the comparator 34. When the room temperature reaches the new set ON temperature X° C. at time TiO in FIG. A dummy resistor Rx=0) is connected,
The set point of the bridge 33 is the set OFF temperature Y°C. At the same time, the compressor 4 is operated due to ON of the comparator 34. When the room temperature reaches the set PFF temperature Y°C, the comparator 34 turns OFF, the compressor 4 stops, and at the same time the set point of the bridge 33 rises to the set ON temperature X°C. Also, 0F of the comparator
The time constant circuit 36 starts discharging due to F and prohibits restarting of the compressor 4 until time Tl3, and repeats the operation of lowering the set point of the bridge 33 to x°C at time Tl3. As can be seen from Figure 4, in the case of mode B, the load on the control room 2 is light, and the swing width of the room temperature is a℃=(X
In addition, the humidity swing in the control room 2 can be made relatively narrow. Note that the transistor 48 in FIG. 3 is turned ON by the output of the load output circuit 39 and drives the relay 25.
Diode 50 is a spike voltage killer for relay 25. Further, 49 and 51 are resistors, and 26 is a light emitting diode that lights up when the compressor 4 is in operation. Reference numeral 27 denotes a light emitting diode, which is lit only during the restart inhibition period T2 in FIG. 4.

Further, a noise prevention capacitor 45 is connected to the thermistor 23. (2) o is a control power supply, and VO is a drive power supply such as Relenor 25, both of which are generated by the power switch 19. Next, an example will be described in which the power switch 19 is turned on to switch the gap voltage of the bridge 33 to quickly start the compressor.

First, turn on the power switch 19 and turn it on. and■D
is given. Then, the power supply reset circuit 40 emits a pulse for a predetermined period of time, and this pulse first initializes the control logic 38 to an initial state. At the same time, a pulse is also applied to the RST terminal of the differential circuit 35, connecting the gap resistor 44 and the resistor 43 in parallel. As a result, the built-in dummy resistor RO of the differential circuit 35
If = 0, new gas PN temperature X°C = set OFF temperature Y
℃, this set temperature and the room temperature are detected, and if the room temperature is high, the comparator 34 turns ON. Therefore, even if the pulse of the power supply reset circuit 40 disappears, the operating point of the bridge 33 does not change because the 0N output of the comparator 34 is input to the differential circuit 35. However, comparator 34
When becomes 0N, the new set ON temperature becomes the set OFF temperature Y
The temperature is switched to ℃. In addition, differential circuit 35
If a built-in dummy resistor RO is provided in the
(Set off-temperature YOC+β°C).

The set temperature and the room temperature are detected, and if the room temperature is high, the comparator 34 turns ON. The output of the comparator 34 operates the differential circuit 35, which switches the new set ON temperature X°C to the set OFF temperature Y°C, operates the compressor 4, and detects a drop in room temperature. It is something. The operation after this is normal operation. This is the explanation of the temperature check when the power is turned on. In addition, the changeover switches 28, 2
By switching 9 and turning it ON, the 4-way valve 5 operates to circulate the refrigerant in the cooling cycle and 2 in the opposite cycle to enter heating operation.

In addition, the changeover switch 29 controls the control logic 38 to invert the output of the comparator 34, and turns the load output circuit 39, transistor 48, and relay 25 to 0FF when the room temperature is high.
2 to stop the operation of the compressor 4. The temperature control device of the present invention has the following effects.

(1) When the power is turned on, set the bridge set point to 0FF.
Temperature near Y℃ (gap temperature at zero or β℃ close to zero)
), the new set ON temperature can be brought closer to , so the heat source can be operated quickly.

In addition, since the gap temperature is changed between the set QFF temperature and the set ON temperature, it maintains high temperature control performance compared to Method 3, which operates the heat source for a certain period of time regardless of the temperature when the power is turned on. The heat source operates more quickly than the conventional method that detects the set ON temperature. Also, for example, if you want to cool down the air conditioner and turn on the power, you can quickly cool down the air conditioner. (2) When the bridge gap voltage (or gap temperature) given only by the output from the comparator is taken as the set gap voltage, the new gap voltage given by the output including the power supply reset circuit should not be zero. By using a dummy resistor or diode in the differential circuit, there is no hunting of the heat source, and the heat source can be stably operated at the newly set gap temperature.

For example, during cooling operation, the set ON temperature X = 27°C,
If the set OFF temperature Y=25°C, the gap temperature a=2°C. This is given by the comparator. However, if the gap temperature is set to 0.3°C using a dummy resistor or the like, the compressor will operate during the time it takes to lower the room temperature by 0.3°C, resulting in stable operation. Furthermore, it is an excellent temperature control device in which fluctuations in room temperature are not a substantial problem.

It goes without saying that this temperature control device can be applied to general temperature control of heating using kerosene or gas, and heating using electric heaters.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a heat source to which the temperature control device of the present invention is applied, Fig. 2 is an electrical wiring diagram of the heat source, Fig. 3 is a block diagram of a temperature control device according to an embodiment of the present invention, and Fig. 4 is a timing chart diagram of the temperature control device. 33... Bridge, 34... Comparator, 35
... Differential circuit, 36 ... Time constant circuit, 37 ... Timer section, 38 ... Control logic, 39 ... Load output circuit, 40 ... ...
・Power reset circuit.

Claims (1)

[Claims] 1. A heat source that performs cooling or heating, a bridge that uses a thermistor etc. to detect the temperature of a controlled object controlled by this heat source, a comparator that turns on and off using the output of this bridge, and an output of this comparator that detects the temperature of the object controlled by the heat source. A load output circuit for driving a load, a power supply reset circuit that outputs a pulse for a predetermined period of time after power-on, a differential circuit that provides a gap voltage of the bridge, and the output of the comparator, etc. and a timer section for forced recovery that operates after a set time after the heat source is stopped by the load output circuit, and at least the comparator, the power supply reset circuit, and the output of the timer section are provided as inputs to the differential circuit. The gap voltage of the bridge circuit provided only by the output from the comparator is the set gap voltage, and the gap voltage given by the output including the power supply reset circuit or the timer section is narrower than the set gap voltage. A temperature control device characterized by being equipped with a diode, a resistor, etc. so that the temperature becomes almost zero.