A method for detecting a refrigerator with multiple temperature sensors before leaving factory

Abstract

The application discloses a kind of multi-temperature sensor refrigerator factory detection method, refrigerator main control board is equipped with main control chip and with temperature sensor quantity matching and one-to-one temperature acquisition circuit, each temperature sensor and refrigerator main control board connection line length All have uniqueness, the method includes the following steps: pretest each temperature sensor two wires between distributed capacitor charging to threshold voltage Time t0, and associated with corresponding temperature acquisition circuit, then preset in refrigerator detection program;Refrigerator enters detection program, only main control board is powered on, main control chip sequentially charges to threshold voltage by each temperature acquisition circuit to the temperature sensor distribution capacitor connected, record charging time t1, if t1 Fall in t0±Δt range, then it indicates that the temperature sensor is connected on corresponding temperature acquisition circuit, otherwise connection error. By detecting the capacitor charging time of different sensor line length, realize sensor connection detection, high reliability, low cost.

Description

Technical Field

[0001] This invention relates to the field of refrigerator technology, and more specifically, to a factory testing method for a refrigerator with multiple temperature sensors. Background Technology

[0002] With the continuous development of refrigerator technology, electronic temperature control relying on temperature sensors to detect temperature has become the mainstream solution for refrigerator temperature control. To meet diverse user needs, refrigerator compartments are becoming increasingly finely categorized, requiring more temperature sensors to detect compartment temperatures. Specifically, the main control board integrates a main control chip and several temperature acquisition circuits, each connected to the main control chip. Additionally, each temperature sensor needs to be connected to its corresponding temperature acquisition circuit. In existing technology, to simplify materials, temperature sensors on the same refrigerator are of the same specification. If, during refrigerator assembly, the wiring harnesses connecting the sensors and the main control board are cross-connected—for example, two wires from the refrigerator temperature sensor are plugged into the pins of the temperature acquisition circuit used to collect the freezer compartment temperature—there is no short circuit or open circuit in the sensor, and the sensor specifications and circuits are identical. Conventional factory testing methods are unlikely to detect the problem, potentially leading to defective refrigerators entering the market. Therefore, it is necessary to improve the existing technology. Summary of the Invention

[0003] The purpose of this invention is to provide a factory testing method for a multi-temperature sensor refrigerator, aiming to at least solve one of the technical problems existing in the prior art. To achieve the above objective, the technical solution adopted is as follows: A factory testing method for a multi-temperature sensor refrigerator, wherein the refrigerator's main control board is equipped with a main control chip and a temperature acquisition circuit that matches the number of temperature sensors in a one-to-one correspondence. The length of the connection line between each temperature sensor and the refrigerator's main control board is unique. The method includes the following steps: The time t0 for the distributed capacitance between the two wires of each temperature sensor to charge to the threshold voltage is pre-tested and associated with the corresponding temperature acquisition circuit, and then preset in the refrigerator detection program. When the refrigerator enters the detection program, only the main control board is powered on. The main control chip sequentially charges the distributed capacitors of the connected temperature sensors to the threshold voltage through each temperature acquisition circuit and records the charging time t1. If t1 falls within the range of t0±Δt, it means that the temperature sensor is connected to the corresponding temperature acquisition circuit; otherwise, the connection is incorrect.

[0004] Preferably, the main control board of the refrigerator is also equipped with a collection simulation switch that matches the number of temperature collection circuits and corresponds one-to-one. The corresponding temperature collection circuit is connected to the collection simulation switch, and each collection simulation switch is connected to the main control chip. The main control board is also equipped with a detection module, which includes a detection analog switch and a charging resistor. Each acquisition circuit is connected to the detection analog switch, the detection analog switch is connected to the charging resistor, and the charging resistor is connected to the main control chip.

[0005] Preferably, the acquisition analog switch is a single-channel analog switch.

[0006] Preferably, the detection simulation switch is a multi-channel simulation switch, and the number of channels matches the number of temperature acquisition circuits.

[0007] Preferably, the resistance of the charging resistor is 80-150kΩ.

[0008] Preferably, the main control chip charges the distributed capacitor of each temperature sensor to the threshold voltage at least three times and calculates the average charging time.

[0009] Preferably, 2μs≤Δt≤5μs.

[0010] Preferably, the number of temperature sensors is three, namely a refrigeration temperature sensor, a freezing temperature sensor, and a variable temperature sensor.

[0011] Compared with the prior art, the present invention has the following beneficial effects: In summary, the factory testing method for a multi-temperature sensor refrigerator described in this embodiment of the invention achieves sensor connection detection by detecting the charging time of capacitors with different sensor line lengths. This method is low in cost, simple in structure, and has high reliability and versatility in the test results. Attached Figure Description

[0012] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a circuit connection diagram of the refrigerator main control board of the present invention. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0015] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0016] A preferred embodiment of the present invention provides a factory testing method for a multi-temperature sensor refrigerator. In this embodiment, the multi-temperature sensor refrigerator includes three temperature sensors of the same model, namely a refrigeration temperature sensor, a freezing temperature sensor, and a variable temperature sensor. Since the installation positions of each sensor in the refrigerator are different, the length of the wire connecting each sensor to the main control board is unique.

[0017] like Figure 1 As shown, the refrigerator main control board includes a main control chip, temperature acquisition circuits that correspond one-to-one with the number of temperature sensors, acquisition analog switches that correspond one-to-one with the number of temperature acquisition circuits, and a detection module. In this embodiment, there are three temperature acquisition circuits and three acquisition analog switches. The corresponding temperature acquisition circuits are connected to the acquisition analog switches, and each acquisition analog switch is connected to the main control chip. The detection module includes a detection analog switch and a charging resistor. Each acquisition circuit is connected to the detection analog switch, the detection analog switch is connected to the charging resistor, and the charging resistor is connected to the main control chip. The resistance value of the charging resistor is 80-150kΩ.

[0018] The acquisition analog switch is a single-channel analog switch that can control the connection and disconnection of its channel. The detection analog switch is a multi-channel analog switch that is independent of each other, and the number of channels matches the number of temperature acquisition circuits, that is, three channels.

[0019] During the refrigerator assembly process, it is necessary to connect each temperature sensor to the corresponding temperature acquisition circuit pin on the main control board. To check for any connection errors, the following method can be used for testing.

[0020] Since the temperature sensor is a dual-core wire, there will be distributed capacitance between the two wires. The longer the wire, the larger the capacitance value. The characteristic that the time it takes for the capacitor to charge to the threshold voltage is proportional to the capacitance value is used to determine whether there is a connection error. The specific method is as follows.

[0021] The time t0 for the distributed capacitance between the two wires of each temperature sensor to charge to the threshold voltage is pre-tested and associated with the corresponding temperature acquisition circuit, and then preset in the refrigerator detection program. For example, the refrigeration temperature sensor wire is 2 meters long, and the test t0=80μs; ​​the freezing temperature sensor wire is 1.5 meters long, and the test t0=60μs; the variable temperature temperature sensor wire is 1 meter long, and the test t0=40μs.

[0022] The refrigerator enters the detection program, with only the main control board powered on and other loads not operating to avoid additional interference that could cause data acquisition deviations. All three acquisition simulation switches are in the off state, and the three paths of the detection simulation switches are sequentially turned on. The main control chip charges the distributed capacitor of the connected temperature sensor to the threshold voltage through the charging resistor and the temperature acquisition circuit, recording the charging time t1. Each path undergoes at least three charge-discharge cycles, and the average charging time is calculated. If the average charging time falls within the corresponding t0±Δt range, where 2μs≤Δt≤5μs, it indicates that the temperature sensor is connected to the corresponding temperature acquisition circuit; otherwise, the connection is incorrect and needs to be checked and the detection repeated.

[0023] During normal operation of the refrigerator, all three acquisition analog switches are in the on state, while the detection analog switch is in the off state.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A factory testing method for a multi-temperature sensor refrigerator, wherein the refrigerator's main control board is equipped with a main control chip and a temperature acquisition circuit that matches the number of temperature sensors in a one-to-one correspondence, and the length of the connection line between each temperature sensor and the refrigerator's main control board is unique, characterized in that... The method includes the following steps: The time t0 for the distributed capacitance between the two wires of each temperature sensor to charge to the threshold voltage is pre-tested and associated with the corresponding temperature acquisition circuit, and then preset in the refrigerator detection program. When the refrigerator enters the detection program, only the main control board is powered on. The main control chip sequentially charges the distributed capacitors of the connected temperature sensors to the threshold voltage through each temperature acquisition circuit and records the charging time t1. If t1 falls within the range of t0±Δt, it means that the temperature sensor is connected to the corresponding temperature acquisition circuit; otherwise, the connection is incorrect.

2. The factory testing method for a multi-temperature sensor refrigerator according to claim 1, characterized in that, The refrigerator's main control board is also equipped with a matching and one-to-one acquisition analog switch that corresponds to the number of temperature acquisition circuits. The corresponding temperature acquisition circuits are connected to the acquisition analog switches, and each acquisition analog switch is connected to the main control chip. The main control board is also equipped with a detection module, which includes a detection analog switch and a charging resistor. Each acquisition circuit is connected to the detection analog switch, the detection analog switch is connected to the charging resistor, and the charging resistor is connected to the main control chip.

3. The factory testing method for a multi-temperature sensor refrigerator according to claim 2, characterized in that, The acquisition simulation switch is a single-channel simulation switch.

4. The factory testing method for a multi-temperature sensor refrigerator according to claim 2, characterized in that, The detection simulation switch is a multi-channel simulation switch, and the number of channels matches the number of temperature acquisition circuits.

5. The factory testing method for a multi-temperature sensor refrigerator according to claim 2, characterized in that, The resistance of the charging resistor is 80-150kΩ.

6. The factory testing method for a multi-temperature sensor refrigerator according to claim 1, characterized in that, The main control chip charges the distributed capacitor of each temperature sensor to the threshold voltage at least three times and calculates the average charging time.

7. The factory testing method for a multi-temperature sensor refrigerator according to claim 1, characterized in that, 2μs≤Δt≤5μs.

8. The factory testing method for a multi-temperature sensor refrigerator according to claim 1, characterized in that, There are three temperature sensors: a refrigeration temperature sensor, a freezing temperature sensor, and a variable temperature temperature sensor.

Images