JPS6149575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature detection circuit in an air conditioner, in which temperature detection circuits provided on the indoor side and the outdoor side are provided with virtual points outside the change area of the indoor temperature sensor. The purpose is to reduce the number of input ports to the control unit by allowing input to the control unit through a single input line, and to use the remaining input ports as other signal input ports to perform more multi-functional control. That is.

Conventionally, the temperature detection circuit in this type of air conditioner inputs the outputs of separately detected temperatures to the control unit through separate lines. In these cases,
Since the number of inputs to the control unit is naturally limited, multi-functional models have the drawbacks of increasing the number of inputs, making it impossible to perform the necessary control when the number of inputs becomes too large, increasing the number of parts, and increasing the cost. Was.

The present invention solves the above-mentioned conventional drawbacks by unifying two outputs.

Hereinafter, the present invention will be described with reference to the accompanying drawings showing one embodiment thereof. Here, as for the refrigeration cycle, a conventionally well-known heat pump type refrigeration cycle may be used, so a description thereof will be omitted.

First, an outline of an electric circuit in an air conditioner will be explained with reference to FIG.

In the figure, 1 indicates an indoor unit, and 2 indicates an outdoor unit. The indoor unit 1 is provided with a heater 3 and an indoor fan motor 4 whose speed can be changed, and the outdoor unit 2 is equipped with a compressor. A motor 5, an outdoor fan motor 6, and a four-way valve 7 are provided. These are relays 8, which are activated by output signals from the control section, which will be described later.
Its operation is controlled by 9, 10, 11, and 12.

Next, the temperature control circuit of the air conditioner having the above configuration will be explained with reference to FIG. Here, the same numbers as those in FIG. 1 are given the same numbers, and the description thereof will be omitted.

In the figure, 13 is an indoor temperature detection circuit;
Reference numeral 14 indicates a control section such as a microcomputer, and reference numeral 15 indicates an indoor interface circuit, both of which are provided in the indoor unit.
The indoor temperature detection circuit 13 includes an indoor temperature sensor 16 that detects the indoor temperature, resistors 17, 18, 19 connected to the output port side of the control section 14,
20, 21, the output of the indoor temperature sensor 16, and the output of each of the resistors 17 to 21 as inputs. Connected to input port I.
Furthermore, the indoor interface circuit 15 is
Resistors 26, 26, 27 and comparator 28,
Consisting of a diode 29 and a comparator 28
The output of the comparator 22 is connected to the same input port of the control unit 14 via the diode 29, as is the output of the comparator 22. 30 is a power source. 3
1 is an outdoor temperature detection circuit, and 32 is an outdoor interface circuit, both of which are provided in the outdoor unit 2. The outdoor detection circuit 31
For example, the outdoor temperature sensor 33 and the comparator 3 detect the outdoor temperature such as the temperature of the outdoor heat exchanger.
4 and multiple resistors 35, 36, 37, 38, 39
The input circuit 32 includes a transistor 40 and a plurality of resistors 41, 42, and 43. 44 is a power source.

Next, details of the control section 14 will be explained with reference to FIG. Here, the same numbers as those in FIG. 2 are given the same numbers, and the explanation is omitted.

In the figure, 14a indicates reference voltage level setting means, and 14b indicates signal level determining means.
The indoor side interface circuit 15 and the outdoor side interface circuit 32 connect the indoor side temperature detection circuit 13 and the outdoor side temperature detection circuit 31. One of the switches of the reference voltage level setting means 14a is turned ON in a time-division manner, and the reference voltage level of the comparator 22 is set by the resistors 17 to 21 of the temperature detection circuit 13. The signal level determining means 14b uses a signal obtained by connecting the output signals of the temperature detecting circuits 13 and 31 to the comparators 22 and 3 of the temperature detecting circuits 13 and 31 when each switch is ON, using an AND signal of each switch of the reference voltage level setting means 14a.
4. Determine the output signal.

Next, the relationship between input signals and output signals in the control section 14 will be explained with reference to FIG.

In the figure, the horizontal axis indicates time t, and the vertical axis indicates signal port _P1 . And a is the reference voltage level of the comparator 22, b is the comparator 2
c is the output level of the comparator 22 (input to the control unit 14) when the comparator 8 is not operating, and c is the level of the comparator 22 when the comparator 28 is operating.
shows the output (input to the control unit 14) level.

The operation of the above configuration will be explained. By periodically turning on one of the right switches of the reference voltage level setting means 14a, a scan signal is output from the output port of the control section 14. As a result, as shown in Fig. 3, the resistors 17 to 21
The three reference voltage levels T ₁ , T ₂ , and I are in a time-division state with a certain period, and are input to the comparator 22 . Here, the reference voltage level I is set outside the variation range T of the temperature sensor 16, and when the input of the comparator 22 is at the I level, the comparator 22 always outputs a signal of H level.
The value of is set. The output of the comparator 22 is always H in the A region of FIG.
In ranges B and C of the reference voltage levels T ₁ and T ₂ within the change range T of 6, H,
An L output signal is output. The output signal of the temperature sensor 16 is input to the control unit 14 or stopped depending on the output signals H and L of the comparator 22 in the B and C regions.

When the change in the outdoor temperature sensor 33 exceeds the point to be detected, the output signal of the comparator 34 becomes H, the output signal of the comparator 28 becomes L, and in the A, B, and C ranges, the signal L is sent to the controller 14. is input. In this way, the indoor temperature is B,
The outdoor temperature is detected by the change in the C range, and the output signal L of the comparator 28 in the A range.

Now, when the resistance value of the outdoor temperature sensor 33 is small (when the temperature is high), the comparator 3 shown in FIG.
The output signal of 4 becomes L, and the transistor 40 becomes
It becomes OFF. As a result, the output of the comparator 28 becomes open, and the current flowing through the resistor 43 is blocked by the diode 29, so the third
The output signal of the comparator 22 in area A in the figure is H
Therefore, signal H is input to the control section 4. Therefore, if the reference voltage level _T1 is the thermo-OFF point and the reference voltage level _T2 is the thermo-ON point, the output level of the indoor temperature sensor 16 is the reference voltage level _T2.
If it is below, the heating thermostat is turned on, and the control unit 14 outputs the output that satisfies this state from the output port, drives the corresponding relays 8 to 12, and configures the electric circuit as shown in a in Figure 1. and perform heating operation.

Next, when the temperature decreases and the resistance value of the outdoor temperature sensor 33 increases, the output of the comparator 34 becomes open, the transistor 40 turns on, and the output signal of the comparator 28 becomes L.
Then, in each area A, B, and C of FIG. 4, the control unit 1
The input signal to No. 4 becomes L, and it is detected that the outdoor temperature has become low. Here, if the outdoor temperature sensor 33 is used to detect the temperature of the outdoor heat exchanger, the first
An electric circuit is formed as shown in Figure b, and defrosting operation is performed. That is, the input signal to the control unit 14 is L.
Then, relays 9 and 10 are turned OFF, the outdoor fan is stopped, the four-way valve is switched, and the cooling cycle is started. At this time, the indoor fan is decelerated by relay 11 on the indoor side, and relay 12 is turned ON. Therefore, the heater 3 is energized.

Therefore, by changing the reference voltage of the indoor temperature detection circuit 13 in a time-sharing manner by the reference voltage level setting means 14a and applying a reference voltage outside the change range of the temperature sensor 16 in one region, the temperature of the other temperature in this region is changed. Each temperature detection circuit 13,
31 output signals can be connected to one line, allowing multi-functional control even though the number of inputs is limited.

In the present embodiment, the reference voltage level is provided outside the variation range of the indoor temperature sensor 16, but the reference voltage level may be provided outside the variation range of the outdoor temperature sensor 33.

Further, the two temperature detection circuits may be located on the indoor side.

As is clear from the above example, the temperature control circuit of the air conditioner at this temperature sets the reference voltage level of one of the temperature detection circuits in a time-sharing manner, and changes the temperature sensor in the set time-sharing area. It has a reference voltage setting means for setting a reference level outside the range, and a signal level determining means for each time-division area, and the signal level determining means sets the reference voltage level to a value that falls within a change range of the temperature sensor. means for performing heating operation by determining the signal level of the common input port in the time-divided time when the reference voltage level is set to a value that falls outside the temperature sensor change range; It has a means for determining the level and performing defrosting operation, and it is possible to input different temperature detection signals to the same input terminal of the control unit, so the number of input terminals used for temperature detection of the control unit can be reduced. Since the number of input terminals of the control unit can be effectively used as input terminals for controlling other functions, the control of other functions is restricted by the number of input terminals for temperature detection. It has various advantages, such as the fact that it has never been used.

[Brief explanation of the drawing]

FIG. 1 is a schematic electrical circuit diagram of an air conditioner equipped with a temperature control circuit according to an embodiment of the present invention during heating operation and defrosting operation, and FIG. 2 is a temperature control circuit diagram of the same air conditioner. FIG. 3 is a block diagram of a control section in the temperature control circuit, and FIG. 4 is a timing chart showing the relationship between input signals and output signals in the control section of the temperature control circuit. 5... Compressor motor, 7... Four-way valve, 13, 31...
Temperature detection circuit, 14...control unit, 14a...reference voltage level setting means, 14b...signal level determination means,
15... Indoor interface circuit, 16, 33
...Temperature sensor, 32...Outdoor side interface circuit.

Claims (1)

[Claims] 1 includes two temperature detection circuits each having a temperature sensor, and a control unit that inputs output signals of the temperature detection circuits to control energization of the compressor motor and refrigerant switching valve, and the control unit Reference voltage level setting means for time-divisionally setting the reference voltage level of one of the temperature detection circuits to a value that falls within the change area of the temperature sensor and a value that falls outside of the change area at a predetermined cycle; and both of the temperature detection circuits. a common input port for inputting the output signal of the common input port; and signal level determining means for determining whether the time-divided reference voltage level is within the change region and inputting the output signal input to the common input port. and the signal level determining means is means for performing heating operation by determining the signal level of the common input port in a time-divided time period in which the reference voltage level is set to a value within a change range of the temperature sensor. and means for performing a defrosting operation by determining a signal level of a common input port in a time-divided time period in which the reference voltage level is set to a value outside a temperature sensor change range. circuit.