KR970009842B1 - Defrosting method in case of defrosting temperature sensor badness of refrigerators - Google Patents

Abstract

The defrosting method upon error generation of defrosting temperature sensor of a refrigerator in which a temperature sensor and a defrosting heater is contained, comprises the steps of: (100)determining whether a defrosting time point is reached;(101)if reached, turning the defrosting heater on; (102)at the same time, setting a predetermined time and counting the set time; (103)detecting whether a predetermined first time elapses; (104)if the first time has elapsed, detecting a temperature of a cooler and determine whether the detected temperature is over a predetermined temperature; (105)if the detected temperature is over the predetermined temperature, detecting whether the detected temperature is a defrosting completion temperature; (106)if the detected temperature is under the predetermined temperature, detecting whether a predetermined second time elapses; and (107)if the predetermined second time has elapsed, turning the defrosting heater off.

Description

Defrosting method when the defrost temperature sensor of the refrigerator is defective

1 is a main circuit diagram of a general refrigerator to which the present invention is applied.

2 is a temperature curve of the cooler during defrosting to explain the present invention.

3 is a control flow diagram illustrating the present invention.

4 is a conventional refrigerator defrosting method.

* Explanation of symbols for main parts of the drawings

10: microcomputer 20: cooler temperature detection circuit

30 defrost heater driving circuit 40 compressor driving circuit

TH: Temperature sensor HTR: Defrost heater

FZ: Hughes

The present invention relates to a defrosting method of a refrigerator, and more particularly, to a defrosting method of a defrosting temperature sensor of a refrigerator for solving the problem of defrosting occurs when the temperature sensor for defrosting causes poor characteristics at all times to detect the low temperature.

Conventionally, when the general defrosting method of the refrigerator through the flow chart of Figure 4, the process of determining whether the defrosting time has arrived 200, wherein the defrosting time is the accumulation time of the compressor (COMPRESSOR) is a predetermined time (Example 6, 8 hours). In step 200, when the defrosting time is detected, a process of dissipating heat to the cooler by energizing the defrosting heater 201 and detecting the completion time of defrosting by detecting the temperature of the cooler through a temperature sensor installed in the cooler 202 And, if the defrosting completion temperature is detected in step 202, the step of closing the defrosting by turning off the defrost heater (204), and if the defrosting completion temperature is not detected in step 202 after the start of the defrosting heater driving And a step (203) of checking whether the predetermined time (90 minutes) has elapsed to keep the defrost heater still in the energized state for the predetermined time. The conventional defrosting method detects the temperature of the cooler. If the temperature sensor that detects the defrosting completion temperature detects a low temperature at all times because of a characteristic defect, the defrosting completion temperature (eg, 10 ° C.) cannot be detected and thus the defrosting process is performed through step 203. The heater is adapted to be cut off after driving for a predetermined time (90 minutes) is set. Therefore, in the process of energizing the defrost heater for a long time of 90 minutes, the overcurrent protection fuse connected in series to the defrost heater is disconnected, and after the fuse is disconnected, the defrost is not performed and thus the Performance deteriorates sharply, which has been raised by consumer claims.

Accordingly, the present invention has been made to solve the above problems, an object of the present invention is a failure of the defrost temperature sensor of the refrigerator so that the defrosting operation can be maintained at a constant level even when the temperature sensor for detecting the cooler temperature causes a characteristic defect It is to provide a defrosting method of the city.

In order to achieve the above object, the present invention provides a defrosting method of a refrigerator including a temperature sensor for detecting a temperature of a cooler, a defrost heater, a process of determining whether a defrost point has arrived, and a defrost point when the defrost point arrives. A process of energizing a commercial heater, a process of setting and counting time at the same time as the defrost heater starts to energize, a process of detecting the passage of a first predetermined time, and a temperature of a cooler when the first predetermined time elapses Detecting whether the temperature is above a certain temperature, and if the temperature of the cooler is above a predetermined temperature, detecting the completion of defrost temperature, and if the temperature of the cooler is below a certain temperature, the elapse of the second predetermined time Detecting the temperature, and the temperature of the cooler is above a certain temperature and the defrosting completion temperature is detected, or the temperature of the cooler is below a certain temperature and the second predetermined When the time elapses, there is a feature provided with a process of blocking the energization of the defrost heater.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a main circuit diagram of a general refrigerator to which the present invention is applied. The one-chip microcomputer 10, a defrosting temperature sensor TH, and a resistor R1, which is a signal processing source of a refrigerator control, with a predetermined program according to the present invention. ) R2 and condenser C1 and C2, the cooler through a signal input to the microcomputer 10 as a change in the voltage (VCC) value by the resistance distribution of the temperature sensor (TH) and the resistor (R1). The cooler temperature detector 20 allows the microcomputer 10 to detect the temperature of the resistor, the resistors R3 to R5, the transistors Q1 and Q2, the relay RY, the diode D1, and the defrost heater. The present invention is applied to a circuit of a refrigerator composed of a defrost heater driving circuit 30 composed of an HTR and a fuse FZ for driving a defrost heater HTR, and a compressor driving circuit 40 for driving a compressor. .

2 shows the temperature curve of the cooler at the time of defrosting. When the defrosting operation is described with reference to this, first, the microcomputer 10 accumulates the time output to the compressor driving circuit 40 to detect the cumulative compressor operation time. When the defrosting time point t1 (the compressor operation accumulation time reaches the set time), the microcomputer 10 outputs a high signal to the output port PO1. At this time, the output high signal turns on the transistor Q1 through the resistor R3, and a low signal is applied to the base of the transistor Q2 by turning on the transistor Q1, thereby turning on the transistor Q2. Accordingly, when the relay RY is turned on and the switch unit is turned on, the power source AC is applied to the defrost heater HTR so that the defrost heater HTR generates heat and defrost is started.

Therefore, the temperature of the cooler continues to rise, and at about twenty minutes after the start of defrosting, the temperature of the cooler rises by about -5 ℃ or more. This temperature varies slightly depending on the type of the refrigerator. Chi. Here, the times t1 to t2 are referred to as the first predetermined time. On the other hand, the temperature of the cooler after the time point t2 is kept for about 10 minutes (t2 to t3) near 0 ° C due to latent heat due to the frost of the cooler. The defrosting completion temperature of the cooler is 10 ° C through the cooler temperature detector 20. When it is detected, the defrosting heater HTR is shut off at the time point t4 to complete the defrosting.

In the normal defrosting method, the control according to the present invention for performing defrosting when the temperature sensor TH detects a low temperature state of the cooler due to poor characteristics will be described below with reference to the flowchart of FIG. 3. .

First, when the power sources AC, VCC, and VCC1 are applied, the microcomputer 10 performs 100 steps of detecting the above-described defrost time t1. At this time, when the defrosting time is detected, the operation of the compressor is stopped by interrupting the output to the compressor driving circuit 40 and outputting a high signal to the defrosting heater driving circuit 30 to drive the defrosting heater HTR. After the time is set, the procedure 102 starts to count. After step 102 of step 102, step 103 is performed to determine whether the first predetermined time t1 to t2 has elapsed. If the first predetermined time (about 20 minutes) has not elapsed in step 103, the heater is driven. After returning to the process of continuing the time coefficient in the state, and after the first predetermined time elapses, a process 104 is performed to determine whether the temperature of the cooler is above a predetermined temperature (about 5 ° C.) through the cooler temperature detection circuit 20. In step 104, if the temperature of the cooler is not higher than the predetermined temperature, the defrost temperature sensor TH is recognized as a defective characteristic, and it is determined whether the minimum time required for defrost has elapsed for a second predetermined time, about 45 minutes (step 106). When the second predetermined time has not elapsed, the process returns to the heater driving process (step 101), and when the second predetermined time has elapsed, the process of step 107 is performed to block driving of the defrost heater HTR. If the temperature of the cooler is above a certain temperature (5 ℃), the process of determining whether the temperature of the cooler is the defrosting completion temperature is performed. If the defrosting completion temperature is not detected, the heater driving process (step 101) returns and if the defrosting completion temperature is detected. Step 107 to block the defrost heater (HTR) is to be performed sequentially.

As described above, the present invention prevents the overcurrent protection fuse connected in series to the defrost heater, which may be caused by the temperature sensor detecting the completion time of defrost, to be disconnected, thereby preventing the fuse from being disconnected. It is a useful invention that can maintain the performance of the refrigerator, which has been rapidly deteriorated due to no defrosting to some extent.

Claims (1)

In a defrosting method of a refrigerator including a temperature sensor for detecting a temperature of a cooler, a defrost heater, a process of determining whether a defrost point has arrived (100), and a process of energizing a defrost heater when the defrost point arrives ( 101), the step 102 of setting the time and start counting at the same time as the start of the defrost heater energization, the step 103 of detecting the elapse of the first predetermined time, and the cooler when the first predetermined time has elapsed Detecting a temperature of the coolant and determining whether the temperature is equal to or higher than a predetermined temperature (104); and detecting a defrosting completion temperature if the coolant is higher than or equal to a predetermined temperature (105); and Determining that the characteristics of the defrost temperature sensor (TH) is less than the step 106 of detecting the elapse of the second predetermined time, the temperature of the cooler is a predetermined temperature or more defrost completion temperature is detected, or the temperature of the cooler Under constant temperature and the second defrosting method when the defrost temperature sensor failure of the refrigerator, characterized in that the provided by the process 107, which, when a predetermined time passes to block the communication of the commercial heaters.