CN210832714U - Defrosting circuit and refrigeration equipment - Google Patents
Defrosting circuit and refrigeration equipment Download PDFInfo
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- CN210832714U CN210832714U CN201921719798.XU CN201921719798U CN210832714U CN 210832714 U CN210832714 U CN 210832714U CN 201921719798 U CN201921719798 U CN 201921719798U CN 210832714 U CN210832714 U CN 210832714U
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Abstract
The embodiment of the utility model provides a defrosting circuit and refrigeration plant is provided to refrigerating system field. The circuit of defrosting is applied to refrigeration plant, and refrigeration plant includes heating element, heating control circuit and controller, and the controller is used for controlling heating control circuit to control heating element's heating state, the circuit of defrosting includes: the temperature detection circuit is used for detecting the temperature in the refrigeration equipment and outputting sampling voltage; the protection circuit is connected with the temperature detection circuit and is used for processing the sampling voltage, and is also connected with the heating control circuit and the controller, and when the temperature is smaller than or equal to a first temperature threshold value, the protection circuit sends a first level signal to the heating control circuit so as to close the heating control circuit; the protection circuit sends a second level signal to the heating control circuit to turn off the heating control circuit when the temperature is greater than or equal to a second temperature threshold, wherein the second temperature threshold is greater than the first temperature threshold. The embodiment of the utility model provides a reliability of defrosting circuit has been promoted.
Description
[ technical field ] A method for producing a semiconductor device
The embodiment of the utility model provides a relate to refrigerating system technical field, especially relate to a defrosting circuit and refrigeration plant.
[ background of the invention ]
The defrosting circuit is arranged on the refrigeration equipment, wherein the refrigeration equipment comprises an evaporator, the evaporator comprises a heating assembly, the existing defrosting circuit comprises a temperature detection circuit, a controller and a heating control circuit, the temperature detection circuit is used for detecting the temperature in the refrigeration equipment, when the temperature is greater than a first temperature threshold value, the controller outputs a control level signal, and the heating control circuit is closed, so that the heating assembly stops heating; when the temperature is lower than the second temperature threshold value, the controller outputs a control level signal and starts the heating control circuit to enable the heating assembly to start heating so as to remove the frost layer on the surface of the evaporator. However, in the event of a failure in the operation of the controller software, it cannot accurately control the heating control circuit, so that the heating assembly operates abnormally, resulting in an excessively low or high temperature within the refrigeration appliance.
[ Utility model ] content
The embodiment of the utility model provides a aim at providing a change white circuit and refrigeration plant, its reliability that can promote the circuit of changing the white.
In order to solve the above technical problem, an embodiment of the present invention provides the following technical solution:
the embodiment of the utility model provides a defrosting circuit is applied to refrigeration plant, refrigeration plant includes heating element, heating control circuit and controller, heating element with heating control circuit connects, heating control circuit still with the controller is connected, the controller is used for control to open or close heating control circuit, in order to control heating element's heating state, defrosting circuit includes:
the temperature detection circuit is respectively connected with an external power supply and the controller and is used for detecting the temperature in the refrigeration equipment and outputting sampling voltage;
a protection circuit connected with the temperature detection circuit and processing the sampling voltage, and further connected with the heating control circuit and the controller, wherein when the temperature is less than or equal to a first temperature threshold, the protection circuit sends a first level signal to the heating control circuit to turn off the heating control circuit; when the temperature is greater than or equal to a second temperature threshold, the protection circuit sends a second level signal to the heating control circuit to close the heating control circuit, wherein the second temperature threshold is greater than the first temperature threshold.
Optionally, the protection circuit comprises:
the voltage division circuit is connected with the external power supply and is used for carrying out voltage division processing on the external power supply to generate a first reference voltage and a second reference voltage;
a comparison circuit connected to the external power supply, the voltage divider circuit, and the temperature detection circuit, respectively, the comparison circuit including a first non-inverting input terminal to which the first reference voltage is applied, a first inverting input terminal to which the sampling voltage is applied, a second non-inverting input terminal to which the sampling voltage is applied, and an output terminal to which the second reference voltage is applied;
the switch circuit is respectively connected with the output end, the controller and the heating control circuit;
when the sampling voltage is greater than or equal to 0V and less than or equal to the second reference voltage, the output end outputs the first level signal, and the switch circuit is used for switching off the heating control circuit according to the first level signal; when the sampling voltage is greater than or equal to the first reference voltage and less than or equal to the output voltage of the external power supply, the output end outputs the second level signal, and the switch circuit is used for switching off the heating control circuit according to the second level signal; the controller is configured to control the heating control circuit when the sampling voltage is greater than the second reference voltage and less than the first reference voltage.
Optionally, the temperature detection circuit comprises an NTC temperature sensor and a first resistor;
one end of the NTC temperature sensor is connected with the external power supply, the other end of the NTC temperature sensor is connected with one end of the first resistor, the first inverting input end and the second non-inverting input end, and the other end of the first resistor is grounded.
Optionally, the voltage divider circuit includes a second resistor, a third resistor, and a fourth resistor;
one end of the second resistor is connected with the external power supply, the other end of the second resistor is connected with one end of the third resistor and the first in-phase input end, the other end of the third resistor is connected with one end of the fourth resistor and the second out-phase input end, and the other end of the fourth resistor is grounded.
Optionally, the comparison circuit includes a first comparator, a second comparator and a fifth resistor;
the non-inverting input end of the first comparator is the first non-inverting input end, the inverting input end of the first comparator is the first inverting input end, and the output end of the first comparator is the output end; the non-inverting input end of the second comparator is the second non-inverting input end, the inverting input end of the second comparator is the second inverting input end, the output end of the second comparator is connected with the output end of the first comparator, the power supply end of the second comparator is connected with the external power supply, and the ground end of the second comparator is grounded; one end of the fifth resistor is connected with the other end of the second resistor, one end of the third resistor and the first non-inverting input end, and the other end of the fifth resistor is connected with the output end of the first comparator, the output end of the second comparator and the switch circuit.
Optionally, the switch circuit includes a diode, a cathode of the diode is connected to the output terminal and the other end of the fifth resistor, and an anode of the diode is connected to the controller and the heating control circuit.
Optionally, the defrosting circuit further comprises:
the filter circuit is electrically connected between the temperature detection circuit and the controller and used for filtering the sampling voltage and then sending the sampling voltage to the controller;
the first current limiting circuit is electrically connected between the temperature detection circuit and the comparison circuit and used for carrying out current limiting processing on the sampling voltage and then sending the sampling voltage to the comparison circuit;
and the second current limiting circuit is respectively connected with the controller, the switch circuit and the heating control circuit and is used for performing current limiting processing on a control level signal which is used for controlling the heating control circuit by the controller.
Optionally, the filter circuit comprises a sixth resistor and a capacitor;
one end of the sixth resistor is connected with the temperature detection circuit, the other end of the sixth resistor is connected with one end of the capacitor and the controller, and the other end of the capacitor is grounded.
Optionally, the first current limiting circuit includes a seventh resistor, and the second current limiting circuit includes an eighth resistor;
one end of the seventh resistor is connected with the temperature detection circuit, and the other end of the seventh resistor is connected with the first inverting input end and the second non-inverting input end; one end of the eighth resistor is connected with the controller, and the other end of the eighth resistor is connected with the switch circuit and the heating control circuit.
The embodiment of the utility model provides a refrigeration plant is still provided, include:
an evaporator comprising a heating assembly;
the heating control circuit is connected with the heating assembly;
the controller is connected with the heating control circuit and used for controlling the heating control circuit to be switched on or switched off so as to control the heating state of the heating assembly;
the defrosting circuit of any one of the above claims connected to the heating control circuit and the controller, respectively.
The utility model has the advantages that: compared with the prior art, the embodiment of the utility model provides a change white circuit and refrigeration plant. The temperature in the refrigeration equipment is detected through the temperature detection circuit, and when the temperature is smaller than or equal to a first temperature threshold value, the protection circuit sends a first level signal to the heating control circuit to close the heating control circuit; when the temperature is greater than or equal to a second temperature threshold value, the protection circuit sends a second level signal to the heating control circuit to close the heating control circuit, wherein the second temperature threshold value is greater than the first temperature threshold value, so that the protection circuit closes the heating control circuit according to the temperature in the refrigeration equipment under the condition that the heating assembly works abnormally due to the operation failure of the controller software, so that the control of the controller is disabled, and the reliability of the defrosting circuit is improved.
[ description of the drawings ]
One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.
Fig. 1 is a schematic structural diagram of a refrigeration apparatus including a defrosting circuit according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a structure of a protection circuit and connections thereof with an external power supply, a temperature detection circuit and other modules of a refrigeration apparatus according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a structure of a defrosting circuit and its connection to an external power supply and other modules of a refrigeration apparatus according to another embodiment of the present invention;
fig. 4 is a schematic diagram of one of the circuit connections corresponding to fig. 3.
[ detailed description ] embodiments
To facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and detailed description. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.
Fig. 1 is a schematic structural diagram of a refrigeration apparatus including a defrosting circuit according to an embodiment of the present invention. As shown in fig. 1, the refrigerating apparatus 100 includes an evaporator 200, a heating control circuit 300, a controller 400, and a defrosting circuit 500. The refrigeration equipment 100 comprises a refrigerator, an electric freezer, a display cabinet, a low-temperature wine cabinet, an air conditioner and the like, and mainly comprises a compressor, an expansion valve, an evaporator 200, a condenser, accessories and pipelines. The device can be divided into a compression refrigeration device, an absorption refrigeration device, a steam jet refrigeration device, a heat pump refrigeration device, an electric heating refrigeration device and the like according to the working principle, and the object and the heat around the object are moved out through the working cycle of the device to cause and maintain a certain low-temperature state.
The evaporator 200 includes a heating assembly 21.
The evaporator 200 is an important component of the refrigeration apparatus 100, and the low-temperature condensed liquid passes through the evaporator 200 to exchange heat with the external air, so that the heat is absorbed through gasification, and the refrigeration effect is achieved. The evaporator 200 is mainly composed of a heating chamber and an evaporation chamber, the heating chamber provides heat required by evaporation for the condensed liquid, the condensed liquid is promoted to boil and vaporize, and the evaporation chamber enables gas and liquid to be completely separated.
In the present embodiment, the heating assembly 21 includes at least one set of heating wires or tubes. In the process of refrigerating the refrigeration equipment 100, frost may be formed on the surface of the evaporator 200, when the frost layer on the surface of the evaporator 200 is thicker and thicker, the flow of the cooling circulation is blocked, the heat absorption effect of the evaporator 200 is reduced, and abnormal temperature reduction of the refrigeration equipment 100 and long-time operation of the compressor are caused, so that in the process of refrigerating the refrigeration equipment 100, the defrosting operation needs to be periodically performed, the heating control circuit 300 is controlled to be turned on by the controller 400, so that current flows through a heating wire or a heating pipe connected with the heating control circuit 300, and the heating wire or the heating pipe generates heat to achieve the effect of removing the frost layer on the surface of the evaporator 200.
In some embodiments, the heating assembly 21 further includes a fuse connected in series with the heating wire, and configured to blow the fuse when an excessive current flows through the heating wire, and cut off an energizing loop of the heating wire, so as to stop heating the heating wire.
The heating control circuit 300 is connected to the heating unit 21.
In this embodiment, the heating control circuit 300 includes a relay switch for operating in an on state or an off state according to a control level signal sent by the controller 400.
The controller 400 is connected to the heating control circuit 300, and is configured to control to turn on or off the heating control circuit 300, so as to control the heating state of the heating element 21.
When the relay switch works in an open state, the power-on loop of the heating assembly 21 is switched on, so that the heating assembly 21 starts to heat; when the relay switch works in the closed state, the power-on loop of the heating assembly 21 is disconnected, so that the heating assembly 21 stops heating.
Referring to fig. 4, the controller 400 includes a MCU1 and its peripheral circuits (not shown), and the MCU1 may be 51 series, Arduino series, STM32 series, or the like. In some embodiments, the controller 400 may also be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), an arm (acorn RISC machine), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components; but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine; or as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The defrosting circuit 500 is connected to the heating control circuit 300 and the controller 400, respectively. The defrosting circuit 500 includes a temperature detecting circuit 10 and a protection circuit 20.
The temperature detection circuit 10 is respectively connected to an external power source 11 and the controller 400, and is configured to detect a temperature in the refrigeration apparatus 100 and output a sampling voltage.
The temperature detection circuit 10 includes an NTC temperature sensor NTC1 and a first resistor R1. One end of the NTC temperature sensor NTC1 is connected to the external power source 11, the other end of the NTC temperature sensor NTC1 is connected to one end of the first resistor R1, the first inverting input terminal (inverting input terminal of the comparator U1A) and the second non-inverting input terminal (non-inverting input terminal of the comparator U1B), and the other end of the first resistor R1 is grounded.
The NTC temperature sensor NTC1 is typically composed of an NTC thermistor and a probe assembly including a metal or plastic housing, extension leads, and metal terminals or connectors, among others. Preferably, the NTC temperature sensor NTC1 is placed near the evaporator 200.
The NTC temperature sensor NTC1 and the first resistor R1 form a voltage dividing circuit, the resistance value of the NTC temperature sensor NTC1 decreases with the increase of temperature, the NTC temperature sensor NTC1 and the first resistor R1 divide the output voltage of the external power supply 11 to output a sampling voltage VI, and the controller 400 divides the output voltage of the external power supply 11 by the NTC temperature sensor NTC1 and the first resistor R1 to output a sampling voltage VIAfter receiving the sampling voltage, calculating the resistance of the NTC temperature sensor NTC1 according to the sampling voltage and the resistance of the first resistor R1, and further obtaining the temperature detected by the NTC temperature sensor NTC 1. The sampling voltage VI-R1 VCC/RNTC1With increasing temperature, RNTC1Decreasing, the sampling voltage VI increasing, or, when the NTC temperature sensor NTC1 is short-circuited, the sampling voltage VI increasing; with decreasing temperature, RNTC1Increasing, the sampling voltage VI decreases, or when the NTC temperature sensor NTC1 is open, the sampling voltage VI decreases to 0V.
The protection circuit 20 is connected to the temperature detection circuit 10 and processes the sampled voltage, and is further connected to the heating control circuit 300 and the controller 400, and when the temperature is less than or equal to a first temperature threshold, the protection circuit 20 sends a first level signal to the heating control circuit 300 to turn off the heating control circuit 300; when the temperature is greater than or equal to a second temperature threshold, which is greater than the first temperature threshold, the protection circuit 20 sends a second level signal to the heating control circuit 300 to turn off the heating control circuit 300.
The embodiment of the utility model provides a refrigeration plant, detect the temperature in the refrigeration plant through the temperature detection circuit, when the temperature is less than or equal to first temperature threshold value, protection circuit sends first level signal to heating control circuit to close heating control circuit; when the temperature is greater than or equal to the second temperature threshold value, the protection circuit sends a second level signal to the heating control circuit to close the heating control circuit, wherein the second temperature threshold value is greater than the first temperature threshold value, so that the protection circuit closes the heating control circuit according to the temperature in the refrigeration equipment under the condition that the heating assembly works abnormally due to the operation failure of the controller software, so that the control of the controller is disabled, and the reliability of defrosting of the refrigeration equipment is improved.
Referring to fig. 2 and fig. 4, the protection circuit 20 includes a voltage divider 201, a comparator 202, and a switch 203.
The voltage dividing circuit 201 is connected to the external power source 11, and is configured to divide the voltage of the external power source 11 to generate a first reference voltage VP and a second reference voltage VN.
In the present embodiment, the voltage divider circuit 201 includes a second resistor R2, a third resistor R3, and a fourth resistor R4. One end of the second resistor R2 is connected to the external power source 11, the other end of the second resistor R2 is connected to one end of the third resistor R3 and the first non-inverting input terminal (non-inverting input terminal of the comparator U1A), the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the second inverting input terminal (inverting input terminal of the comparator U1B), and the other end of the fourth resistor R4 is grounded.
The second resistor R2, the third resistor R3 and the fourth resistor R4 are serially connected to divide voltage, the third resistor R3 and the fourth resistor R4 are serially connected to be equivalent to a resistor R34, the second resistor R2 and the resistor R34 are serially connected to divide voltage to obtain the first reference voltage VP, and the first reference voltage VP is applied to the non-inverting input end of the first comparator U1A. The second resistor R2 and the third resistor R3 are equivalent to a resistor R23 in series, the resistor R23 and the fourth resistor R4 are connected in series to divide voltage to obtain the second reference voltage VN, and the second reference voltage VN is applied to the inverting input terminal of the second comparator U1B. The ratio of the second resistor R2 to the resistor R34 is greater than the ratio of the resistor R23 to the fourth resistor R4, so that the first reference voltage VP is greater than the second reference voltage VN.
The comparison circuit 202 is connected to the external power supply 11, the voltage divider circuit 201, and the temperature detection circuit 10, respectively, and the comparison circuit 202 includes a first non-inverting input terminal to which the first reference voltage is applied, a first inverting input terminal to which the sampling voltage is applied, a second non-inverting input terminal to which the sampling voltage is applied, and an output terminal to which the second reference voltage is applied.
The comparison circuit 202 includes a first comparator U1A, a second comparator U1B, and a fifth resistor R5. Wherein the non-inverting input terminal of the first comparator U1A is the first non-inverting input terminal, the inverting input terminal of the first comparator U1A is the first inverting input terminal, and the output terminal of the first comparator U1A is the output terminal; the non-inverting input terminal of the second comparator U1B is the second non-inverting input terminal, the inverting input terminal of the second comparator U1B is the second inverting input terminal, the output terminal of the second comparator U1B is connected to the output terminal of the first comparator U1A, the power supply terminal of the second comparator U1B is connected to the external power supply 11, and the ground terminal of the second comparator U1B is grounded; one end of the fifth resistor R5 is connected to the other end of the second resistor R2, one end of the third resistor R3, and the first non-inverting input terminal, and the other end of the fifth resistor R5 is connected to the output terminal of the first comparator U1A, the output terminal of the second comparator U1B, and the switch circuit 203.
In this embodiment, the comparison circuit 202 includes a dual voltage comparator integrated circuit LM393, and the dual voltage comparator integrated circuit LM393 includes 8 pins, which respectively correspond to: the first non-inverting input terminal, the first output terminal, the second non-inverting input terminal, the second output terminal, the power supply terminal and the ground terminal. The dual voltage comparator integrated circuit LM393 includes two independent, high precision voltage comparators, a first comparator U1A and a second comparator U1B.
Specifically, the non-inverting input terminal of the first comparator U1A is connected to a corresponding pin of the first non-inverting input terminal of the dual-voltage comparator integrated circuit LM393, that is, the non-inverting input terminal of the first comparator U1A is the first non-inverting input terminal of the dual-voltage comparator integrated circuit LM 393; the inverting input terminal of the first comparator U1A is connected to the corresponding pin of the first inverting input terminal of the dual voltage comparator integrated circuit LM393, i.e., the inverting input terminal of the first comparator U1A is the first inverting input terminal of the dual voltage comparator integrated circuit LM 393. The non-inverting input terminal of the second comparator U1B is connected to the corresponding pin of the second non-inverting input terminal of the dual voltage comparator integrated circuit LM393, that is, the non-inverting input terminal of the second comparator U1B is the second non-inverting input terminal of the dual voltage comparator integrated circuit LM 393; an inverting input terminal of the second comparator U1B is connected to a corresponding pin of a second inverting input terminal of the dual voltage comparator integrated circuit LM393, that is, the inverting input terminal of the second comparator U1B is the second inverting input terminal of the dual voltage comparator integrated circuit LM 393; the output terminal of the first comparator U1A is connected to the corresponding pin of the output terminal of the second comparator U1B, i.e., the output terminal of the first comparator U1A and the output terminal of the second comparator U1B are both the output terminals of the dual voltage comparator integrated circuit LM 393.
Further, when the dual-voltage comparator integrated circuit LM393 is supplying power to the single power supply, the power terminal of the first comparator U1A is floating, the ground terminal of the first comparator U1A is floating, the power terminal of the second comparator U1B is connected to the external power supply 11 (for receiving the power supply voltage VCC), and the ground terminal of the second comparator U1B is grounded; alternatively, the power terminal of the first comparator U1A is connected to the external power source 11, the ground terminal of the first comparator U1A is grounded, the power terminal of the second comparator U1B is floating, and the ground terminal of the second comparator U1B is floating; when the dual-voltage comparator integrated circuit LM393 is powered by dual power sources, the power source terminal of the first comparator U1A is connected to the external power source 11, the ground terminal of the first comparator U1A is grounded, the power source terminal of the second comparator U1B is connected to the external power source 11, and the ground terminal of the second comparator U1B is grounded.
The dual voltage comparator integrated circuit LM393 is configured to output a voltage VO according to the sampling voltage VI, the first reference voltage VP, and the second reference voltage VN. When VI is greater than or equal to 0 and less than or equal to VN, the LM393 of the dual-voltage comparator outputs a first level signal, wherein the first level signal is a low level signal, and VO is 0; when VN is more than VI and less than VP, the dual-voltage comparator integrated circuit LM393 outputs a high level signal, and VO is 1; when VP is less than or equal to VI and less than or equal to VCC, the dual voltage comparator integrated circuit LM393 outputs a second level signal, which is a low level signal, and VO is 0.
The switch circuit 203 is connected to the output terminal, the controller, and the heating control circuit 300, respectively. When the sampling voltage is greater than or equal to 0V and less than or equal to the second reference voltage, the output terminal outputs the first level signal, and the switch circuit 203 is configured to turn off the heating control circuit 300 according to the first level signal; when the sampling voltage is greater than or equal to the first reference voltage and less than or equal to the output voltage of the external power supply 11, the output terminal outputs the second level signal, and the switch circuit 203 is configured to turn off the heating control circuit 300 according to the second level signal; when the sampling voltage is greater than the second reference voltage and less than the first reference voltage, the controller 400 is configured to control the heating control circuit 300.
The switch circuit 203 includes a diode D1, a cathode of the diode D1 is connected to the output terminal and the other end of the fifth resistor R5, and an anode of the diode D1 is connected to the controller 400 and the heating control circuit 300.
The diode D1 has a unidirectional conductivity, when VO is greater than VC, that is, when the dual voltage comparator integrated circuit LM393 outputs a high level signal and VO is 1, the diode D1 is turned off, and the heating control circuit 300 is controlled by the controller 400 according to the temperature; when the voltage difference between VO and VC is smaller than the conducting voltage drop of the diode D1, that is, the dual voltage comparator integrated circuit LM393 outputs a low level signal, and VO is equal to 0, the diode D1 is turned on, VC is pulled low, so that the heating control circuit 300 operates in an off state, the power-on loop of the heating element 21 is cut off, the heating element 21 stops heating, and at this time, the controller 400 is configured to control the control level signal of the heating control circuit to be inactive to the heating control circuit 300 regardless of whether the control level signal is a high level or a low level.
Please refer to fig. 3, which is a schematic diagram of a defrosting circuit and its connection with an external power source and other modules of a refrigeration device according to another embodiment of the present invention. The defrosting circuit 600 includes the defrosting circuit 500 according to the above embodiments, and please refer to the above embodiments for the same parts, which are not described in detail herein. The defrosting circuit 600 further includes a filter circuit 30, a first current limiting circuit 40, and a second current limiting circuit 50.
The filter circuit 30 is electrically connected between the temperature detection circuit 10 and the controller 400, and is configured to filter the sampling voltage and send the filtered sampling voltage to the controller 400.
Referring again to fig. 4, the filter circuit 30 includes a sixth resistor R6 and a capacitor C1. One end of the sixth resistor R6 is connected to the temperature detection circuit 10, the other end of the sixth resistor R6 is connected to one end of the capacitor C1 and the controller 400, and the other end of the capacitor C1 is grounded.
The first current limiting circuit 40 is electrically connected between the temperature detecting circuit 10 and the comparing circuit 202, and is configured to perform current limiting processing on the sampled voltage and send the processed sampled voltage to the comparing circuit 202.
The first current limiting circuit 40 includes a seventh resistor R7, one end of the seventh resistor R7 is connected to the temperature detecting circuit 10, and the other end of the seventh resistor R7 is connected to the first inverting input terminal and the second non-inverting input terminal.
The second current limiting circuit 50 is respectively connected to the controller 400, the switch circuit 203 and the heating control circuit 300, and is configured to perform current limiting processing on a control level signal of the controller 400 for controlling the heating control circuit 300.
The second current limiting circuit 50 includes an eighth resistor R8, one end of the eighth resistor R8 is connected to the controller 400, and the other end of the eighth resistor R8 is connected to the switch circuit 203 and the heating control circuit 300.
In summary, the defrosting circuit 600 works as follows:
the NTC temperature sensor NTC1 detects the temperature in the refrigeration apparatus 100, the resistance of the NTC temperature sensor NTC1 decreases with the increase of the temperature, and the NTC temperature sensor NTC1 and the first resistor R1 divide the voltage of the external power supply 11 and output a sampling voltage VI. The sampling voltage VI is sent to the single chip microcomputer MCU1 after being filtered by the sixth resistor R6 and the capacitor C1, the single chip microcomputer MCU1 calculates the resistance of the NTC temperature sensor NTC1 according to the sampling voltage VI after being filtered and the resistance of the first resistor R1, so that the temperature in the refrigeration equipment 100 is obtained, the single chip microcomputer MCU1 outputs a control level signal according to the temperature, the eighth resistor R8 obtains the voltage VC after performing current-limiting processing on the control level signal, and the voltage VC is used for controlling the heating control circuit 300 to be turned on or turned off.
In addition, after the current limiting process of the seventh resistor R7, the sampling voltage VI is applied to the inverting input terminal of the comparator U1A and the non-inverting input terminal of the comparator U1B, the second resistor R2, the third resistor R3 and the fourth resistor R4 are serially connected to divide the voltage, and the external power source 11 is divided to generate a first reference voltage VP and a second reference voltage VN, the first reference voltage VP is applied to the non-inverting input terminal of the comparator U1A, and the second reference voltage VN is applied to the inverting input terminal of the comparator U1B; when VI is greater than or equal to 0 and less than or equal to VN, the comparison circuit 202 outputs a first level signal VO, the first level signal VO is a low level signal and meets the conduction condition of the diode D1, the diode D1 is turned on, and VC is pulled low, so that the heating control circuit 300 works in a closed state, and at this time, no matter what level signal the single-chip microcomputer MCU1 outputs, the working state of the heating control circuit 300 cannot be controlled; when VP is less than or equal to VI and less than or equal to VCC, the comparison circuit 202 outputs a second level signal VO, the second level signal VO is a low level signal and meets the conduction condition of the diode D1, the diode D1 is turned on, and VC is pulled low, so that the heating control circuit 300 works in a closed state, and at this time, no matter what level signal the single-chip microcomputer MCU1 outputs, the working state of the heating control circuit 300 cannot be controlled; when VN < VI < VP, the comparison circuit 202 outputs a high level signal VO, the conduction condition of the diode D1 is not met, the diode D1 is cut off, and the single chip microcomputer MCU1 is used for controlling the operation of the heating control circuit 300.
The embodiment of the utility model provides a defrosting circuit, detect the temperature in the refrigeration plant through the temperature detection circuit, when the temperature is less than or equal to first temperature threshold value, protection circuit sends first level signal to heating control circuit to close heating control circuit; when the temperature is greater than or equal to a second temperature threshold value, the protection circuit sends a second level signal to the heating control circuit to close the heating control circuit, wherein the second temperature threshold value is greater than the first temperature threshold value, so that the protection circuit closes the heating control circuit according to the temperature in the refrigeration equipment under the condition that the heating assembly works abnormally due to the operation failure of the controller software, so that the control of the controller is disabled, and the reliability of the defrosting circuit is improved.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments can be combined, steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. The utility model provides a defrosting circuit, is applied to refrigeration plant, refrigeration plant includes heating element, heating control circuit and controller, heating element with heating control circuit connects, heating control circuit still with the controller is connected, the controller is used for control to open or close heating control circuit, in order to control heating element's heating state, its characterized in that, defrosting circuit includes:
the temperature detection circuit is respectively connected with an external power supply and the controller and is used for detecting the temperature in the refrigeration equipment and outputting sampling voltage; and
a protection circuit connected with the temperature detection circuit and processing the sampling voltage, and further connected with the heating control circuit and the controller, wherein when the temperature is less than or equal to a first temperature threshold, the protection circuit sends a first level signal to the heating control circuit to turn off the heating control circuit; when the temperature is greater than or equal to a second temperature threshold, the protection circuit sends a second level signal to the heating control circuit to close the heating control circuit, wherein the second temperature threshold is greater than the first temperature threshold.
2. The defrost circuit of claim 1, wherein the protection circuit comprises:
the voltage division circuit is connected with the external power supply and is used for carrying out voltage division processing on the external power supply to generate a first reference voltage and a second reference voltage;
a comparison circuit connected to the external power supply, the voltage divider circuit, and the temperature detection circuit, respectively, the comparison circuit including a first non-inverting input terminal to which the first reference voltage is applied, a first inverting input terminal to which the sampling voltage is applied, a second non-inverting input terminal to which the sampling voltage is applied, and an output terminal to which the second reference voltage is applied; and
the switch circuit is respectively connected with the output end, the controller and the heating control circuit;
when the sampling voltage is greater than or equal to 0V and less than or equal to the second reference voltage, the output end outputs the first level signal, and the switch circuit is used for switching off the heating control circuit according to the first level signal; when the sampling voltage is greater than or equal to the first reference voltage and less than or equal to the output voltage of the external power supply, the output end outputs the second level signal, and the switch circuit is used for switching off the heating control circuit according to the second level signal; the controller is configured to control the heating control circuit when the sampling voltage is greater than the second reference voltage and less than the first reference voltage.
3. The defrosting circuit of claim 2 wherein the temperature detection circuit comprises an NTC temperature sensor and a first resistor;
one end of the NTC temperature sensor is connected with the external power supply, the other end of the NTC temperature sensor is connected with one end of the first resistor, the first inverting input end and the second non-inverting input end, and the other end of the first resistor is grounded.
4. The defrosting circuit of claim 3 wherein the voltage divider circuit comprises a second resistor, a third resistor, and a fourth resistor;
one end of the second resistor is connected with the external power supply, the other end of the second resistor is connected with one end of the third resistor and the first in-phase input end, the other end of the third resistor is connected with one end of the fourth resistor and the second out-phase input end, and the other end of the fourth resistor is grounded.
5. The defrosting circuit of claim 4 wherein the comparison circuit comprises a first comparator, a second comparator and a fifth resistor;
the non-inverting input end of the first comparator is the first non-inverting input end, the inverting input end of the first comparator is the first inverting input end, and the output end of the first comparator is the output end; the non-inverting input end of the second comparator is the second non-inverting input end, the inverting input end of the second comparator is the second inverting input end, the output end of the second comparator is connected with the output end of the first comparator, the power supply end of the second comparator is connected with the external power supply, and the ground end of the second comparator is grounded; one end of the fifth resistor is connected with the other end of the second resistor, one end of the third resistor and the first non-inverting input end, and the other end of the fifth resistor is connected with the output end of the first comparator, the output end of the second comparator and the switch circuit.
6. The defrosting circuit of claim 5 wherein the switching circuit comprises a diode, a cathode of the diode is connected to the output terminal and the other end of the fifth resistor, and an anode of the diode is connected to the controller and the heating control circuit.
7. The defrost circuit of claim 2, further comprising:
the filter circuit is electrically connected between the temperature detection circuit and the controller and used for filtering the sampling voltage and then sending the sampling voltage to the controller;
the first current limiting circuit is electrically connected between the temperature detection circuit and the comparison circuit and used for carrying out current limiting processing on the sampling voltage and then sending the sampling voltage to the comparison circuit; and
and the second current limiting circuit is respectively connected with the controller, the switch circuit and the heating control circuit and is used for performing current limiting processing on a control level signal which is used for controlling the heating control circuit by the controller.
8. The defrosting circuit of claim 7 wherein the filter circuit comprises a sixth resistor and a capacitor;
one end of the sixth resistor is connected with the temperature detection circuit, the other end of the sixth resistor is connected with one end of the capacitor and the controller, and the other end of the capacitor is grounded.
9. The defrosting circuit of claim 7 wherein the first current limiting circuit comprises a seventh resistor and the second current limiting circuit comprises an eighth resistor;
one end of the seventh resistor is connected with the temperature detection circuit, and the other end of the seventh resistor is connected with the first inverting input end and the second non-inverting input end; one end of the eighth resistor is connected with the controller, and the other end of the eighth resistor is connected with the switch circuit and the heating control circuit.
10. A refrigeration apparatus, comprising:
an evaporator comprising a heating assembly;
the heating control circuit is connected with the heating assembly;
the controller is connected with the heating control circuit and used for controlling the heating control circuit to be switched on or switched off so as to control the heating state of the heating assembly; and
the defrosting circuit of any of claims 1 to 9 connected to the heating control circuit and the controller, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921719798.XU CN210832714U (en) | 2019-10-14 | 2019-10-14 | Defrosting circuit and refrigeration equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921719798.XU CN210832714U (en) | 2019-10-14 | 2019-10-14 | Defrosting circuit and refrigeration equipment |
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| CN210832714U true CN210832714U (en) | 2020-06-23 |
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| CN201921719798.XU Active CN210832714U (en) | 2019-10-14 | 2019-10-14 | Defrosting circuit and refrigeration equipment |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115904851A (en) * | 2023-01-10 | 2023-04-04 | 荣耀终端有限公司 | Terminal equipment and external equipment access detection system |
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2019
- 2019-10-14 CN CN201921719798.XU patent/CN210832714U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115904851A (en) * | 2023-01-10 | 2023-04-04 | 荣耀终端有限公司 | Terminal equipment and external equipment access detection system |
| CN115904851B (en) * | 2023-01-10 | 2023-08-15 | 荣耀终端有限公司 | Terminal equipment and external equipment access detection system |
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