JPH0128308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forced cooling operation control circuit that forcibly cools a refrigerator as desired.

Generally, forced cooling control of a refrigerator, which performs forced cooling by continuously operating a compressor using a forced cooling switch, is such that cooling operation is performed for a certain period of time regardless of the ambient temperature of the refrigerator.
However, if you put hot food in the freezer and want to freeze it quickly, you can preserve it properly by letting it quickly pass through the ice crystal formation zone, but depending on the ambient temperature of the refrigerator, The time it takes to cool down to the appropriate freezing temperature is different; it is slower when the outside temperature is high, and faster when the outside temperature is low. Freezers had the disadvantage of being too cold and wasting electricity.

Therefore, the present invention detects the ambient temperature of the refrigerator, changes the forced cooling operation time according to the ambient temperature, and shortens it when the outside temperature is low, thereby performing forced cooling without using unnecessary power. .

An embodiment of the present invention will be described below.

Reference numeral 1 denotes an internal temperature detection circuit, which is composed of a comparator 2, resistors R ₁ , R ₂ , R ₃ , a thermistor, and TH1.

The resistors R ₂ and R ₃ are connected and the comparator 2
It is also connected to one input of. Further, the resistor _R1 and thermistor TH1 are connected, and also connected to other inputs of the comparator 2. And the resistance R ₁ ,
The other end of _R2 is connected to the V _CC power supply, thermistor TH1, and the resistor
The other end of _R3 is connected to ground (hereinafter referred to as GND).

The output of comparator 2 is connected to one input of OR circuit 3, and the output is the base resistance of transistor 4.
Connected to _R4 . A relay 5 is connected to the collector of the transistor 4, and the other end of the relay 5 is connected to V _CC . The emitter of transistor 4 is connected to GND. A normally open contact 6 of the relay 5 is connected to one end of an AC power source 8 and a compressor 7, and the other end of the compressor 7 is connected to the AC power source 8. 9 is an outside temperature detection circuit, which includes a comparator 10 resistors R ₅ , R ₆ , R ₇ and a thermistor.
It consists of TH2. It is connected to the resistors R ₆ and R ₇ and one input of the comparator 10, and is connected to the resistor R ₅ , the thermistor TH2, and the other input of the comparator 10, respectively.

The other ends of the resistors R ₅ and R ₆ are connected to the V _CC power supply and the thermistor TH2, and the other end of the resistor R ₇ is connected to GND.

The output of comparator 10 is connected to the base resistor R ₈ of transistor 12 . The connector of transistor 12 is connected to capacitor _C2 ,
Connected to GND.

11 is an oscillation circuit consisting of resistor _R9 , capacitor _C1 and
Charging and discharging are performed with a time constant determined by _C2 , and a pulse that becomes a clock signal is generated at the output. The clock terminal of this oscillation circuit 11 is connected to the resistor _R9 and capacitors _C1 and _C2 , respectively. And the other end of resistor _R9 is V _CC power supply, capacitor
The other end of _C1 is connected to GND. 13 is a timer, flip-flop circuits FF1, FF2...
It consists of FF7, each Q output is connected to the clock input. Also, the Q output and data input are connected respectively. The input of the timer 13, that is, the clock input of the flip-flop circuit FF1 and the Q output of the oscillation circuit 11 are connected.

14 is a switch for forced cooling, one end is connected to the V _CC power supply, and the other end is connected to the resistor R ₁₀ flip-flop circuit 15
Connected to the clock input. And resistance
The other end of _R10 is connected to GND. The output and data input of the flip-flop circuit 15 are connected, and the Q output is connected to the reset terminal of the oscillation circuit 11 and the OR
It is connected to each input of the circuit 3, the AND circuit 16, and the base resistor _R11 of the transistor 18, respectively.
The other inputs of the AND circuit 16 are connected to the final stage output of the timer 13, that is, the output of the flip-flop circuit FF7, and the output of the AND circuit 16 is connected to the input of the one-shot circuit 17. The output of the one-shot circuit 17 is connected to the reset terminal of each flip-flop circuit FF1, FF2, . . . FF7 of the timer 13 and to the reset terminal of the flip-flop circuit 15, respectively.

The collector of the transistor 18 is connected to the display 19 which is being strongly cooled through a resistor _R12 . The other end of the display 19 is connected to the V _CC power supply. The emitter of transistor 18 is GND
is connected to. FIG. 2 shows changes in temperature inside the refrigerator after forced cooling operation under different outside temperatures. The temperature inside the refrigerator will drop faster when the outside temperature is low than when the outside temperature is high.

Next, the operation of the circuit configured as described above will be explained. Assume that thermistor TH1 is placed inside the freezer compartment of the refrigerator, and thermistor TH2 is placed outside the refrigerator. Thermistor TH placed inside the refrigerator
1 has a small resistance value when the temperature is high, and the potential at point B is lower than the potential at point A, so the output of comparator 2 is "1". When the output of this comparator 2 is "1", the first input of the OR circuit 3 becomes "1", the output becomes "1" regardless of the state of the other inputs, and the transistor ₄ is turned on via the base resistor R4. state, and the relay 5 is energized. The normally open contact 6 of this relay 5 is closed to connect the AC power source 8 to the compressor 7, and the compressor 7 starts to cool the inside of the refrigerator through a refrigeration cycle. When the temperature inside the refrigerator decreases due to the operation of the compressor 7, the resistance of the thermistor TH1 gradually increases. When the temperature inside the refrigerator falls below the set value, the resistance of the thermistor TH1 increases and the potential at point B becomes higher than the potential at point A. Therefore, the output of comparator 2 becomes "0". When the output of comparator 2 becomes “0”, 1 of OR circuit 3
The input becomes "0". At this time, if the Q output of the flip-flop circuit 15 is "0", the OR circuit 3
Both inputs become "0", transistor 4 is turned off, and relay 5 stops operating. When the relay 5 stops operating, the normally open contact 6 is opened, and the compressor 7 is disconnected from the AC power source 8 and stops operating. As a result, the cooling operation is stopped, the temperature inside the refrigerator gradually increases, and the resistance of the thermistor TH1 decreases. When the temperature inside the refrigerator increases and exceeds the set value, the potential at point B becomes lower than the potential at point A due to the resistance value of thermistor TH1 as described above, the output of comparator 2 becomes "1", and compressor 7 goes into cooling operation as described above. Start.

In this way, the compressor 7 is repeatedly operated and stopped by the thermistor TH1.

And thermistor TH2 that detects the outside temperature
For example, when detecting a temperature of 20°C or higher, the potential at point D is lower than the potential at point C, and comparator 1
It operates so that the output of 0 becomes "1", and if the thermistor TH2 detects that the temperature is below 20℃, the voltage at point C becomes lower than D.
If the point potential is high, the comparator 10 operates so that its output becomes "0".

For example, if the outside temperature is 20°C, the output of the comparator 10 becomes "1" as described above, the transistor 12 is turned on, and the clock pulse of the oscillation circuit 11 is generated by the resistor R ₉ and the capacitor (C ₁ + C ₂ ).
It will oscillate with a time constant made up of. However, if the reset terminal of the oscillation circuit 11 is "0", the oscillation is stopped.

Therefore, the forced cooling switch 14 is activated, and when it is turned on, the flip-flop circuit 15
operates and the Q output changes from "0" to "1". The forced cooling switch 14 is a switch that is turned on only while being pressed, and turned off when the pressing is stopped.

When forced cooling is commanded by pressing the forced cooling switch 14, the Q of the flip-flop circuit 15 changes.
The output becomes "1" and one input of the OR circuit 3 becomes "1". Therefore, the output of OR circuit 3 is “1”
Then, as described above, the compressor 7 is activated by the operation of the transistor 4, and the cooling operation is started. Q output of flip-flop circuit 15 is “1”
When this occurs, the transistor 18 is turned on, and the strong cooling indicator 19 lights up to indicate that strong cooling is in progress. At the same time, the reset terminal of the oscillation circuit 11 becomes "1" and enters an oscillation state.

Since the outside temperature is over 20℃, there is no resistance as described above.
It oscillates with a time constant determined by the _R9 capacitor (C ₁ + C ₂ ) and outputs a pulse from the Q output. The timer 13 receives pulses from the Q output of the oscillation circuit 11 and counts the pulses. Counting operation progresses
When _T1 time has elapsed, the output of the timer 13, that is, the output of the flip-flop circuit FF7 becomes "1". When the output of flip-flop circuit FF7 becomes "0", one input of AND circuit 16 becomes "1",
Other inputs become "0" and the output changes from 1 to "0". In response to this signal change, one-shot circuit 1
7 operates and outputs one positive pulse. A reset signal is sent to each reset terminal of the flip-flop circuits FF1, FF2...FF7 of the timer 13 and the flip-flop circuit 15 by the pulse of the one-shot circuit 17, and the count number of the timer 13 is set to 0.
Reset to . The flip-flop circuit 15 is also reset, the Q output changes from "1" to "0", and the forced cooling operation is stopped.

When the Q output of the flip-flop circuit 15 becomes "0", the transistor 18 is turned off and the display 19 during intense cooling is turned off. At the same time, the set terminal of the oscillation circuit 11 becomes "0" and oscillation is stopped. Furthermore
One input of the OR circuit 3 becomes "0". Since the interior of the refrigerator is sufficiently cooled by the forced cooling operation, the output of comparator 2 is in the state of "0", and the two inputs of OR circuit 3 are both "0", the output is "0", and transistor 4 is in the off state. Therefore, the normally open contact 6 of the relay 15 is opened, and the compressor 7 is connected to the AC power source 8.
The connection will be broken and the operation will stop. As a result, the forced cooling operation will end after T ₁ hour if the outside temperature is 20°C or higher.

The time T ₁ is formed by the pulse generated by the resistor R ₉ and the capacitor (C ₁ +C ₂ ) and is calculated from T ₁ =R ₉ ×(C ₁ +C ₂ )/1.46 ×127.

Next, a case where the outside air temperature is 20°C or less will be explained. When the outside temperature is 20° C. or lower, the output of the comparator 10 becomes "0" as described above, and the transistor 12 is turned off. Therefore, the pulse of the oscillation circuit 11 becomes a pulse with a time constant determined by the resistor _R9 and the capacitor _C1 . When the forced cooling switch 14 is activated and forced cooling operation is commanded, the compressor 7 operates as described above and performs the cooling operation, and the intense cooling indicator 19 lights up to indicate that intense cooling is in progress. Display. Further, the reset terminal of the oscillation circuit 11 becomes "1" and outputs a pulse with a time constant determined by the resistor _R9 and the capacitor _C1 , and the timer 13 counts this pulse. When the count advances to _T2 hours, the final stage output of the timer 13, that is, the output of the flip-flop circuit FF7 changes from "1" to "0", and as described above, the timer 13 resets the count to 0 to stop the strong cooling operation. Compressa 7
stops, the strong cooling indicator 19 goes out, and the forced cooling operation ends. After that, the operation and stop of the compressor is controlled in accordance with the output of the comparator 2 operated by the thermistor TH1 that detects the temperature inside the refrigerator.

Forced cooling operation time T ₂ when outside temperature is below 20℃ is resistance
It consists of R ₉ and capacitor C ₁ , and the time is calculated from T ₂ = R ₉ ×C ₁ /1.46 × 127. Therefore, the outside temperature is 20
The relationship between T ₁ hour below ℃ and T ₂ hours below 20℃ is
T ₁ > T ₂ , the forced cooling operation is longer when the outside temperature is high, and shortened when the outside temperature is low.
It is controlled in stages. Further, when the forced cooling switch 14 is operated during the forced cooling operation, the Q output of the flip-flop circuit 15 changes from "1" to "0", and the forced cooling operation is stopped as described above.
Therefore, the forced cooling operation can also be stopped manually.

As described above, according to the present invention, the forced cooling operation is performed by operating the switch, and the forced cooling time is arbitrarily controlled according to the ambient temperature of the refrigerator. Since the cooling operation is performed, food is quickly cooled when the outside temperature is low, and the drawback of wasting electricity due to unnecessary cooling operation due to the cooling operation still being performed even when the temperature reaches the appropriate storage temperature is eliminated, and furthermore This method has great effects such as being able to be implemented at low cost.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram showing a strong cooling operation control circuit of a refrigerator according to an embodiment of the present invention, and FIG. 2 is a diagram showing temperature changes inside the refrigerator during forced cooling operation. TH1...Thermistor, 7...Compressor, TH
2... Thermistor, 11... Oscillation circuit, 13... Timer, 14... Forced cooling switch.

Claims (1)

[Claims] 1. A compressor that cools the inside of the refrigerator, a thermistor that detects the temperature inside and outside the refrigerator, a timer consisting of a flip-flop circuit, an oscillation circuit that can switch in multiple stages to change the operating time of the timer, and a The switch forcibly operates the compressor, operates a timer by the pulses of the oscillation circuit, stops the operation by the output of the switch or timer, and operates the compressor by the output of the oscillation circuit. A forced cooling operation control circuit for a refrigerator that changes the operating time by increasing or decreasing the circuit pulse using a thermistor that detects the outside temperature.