Over-temperature protection circuit and protection system for LED lamp panel of clothes airing machine

Abstract

The utility model discloses an over-temperature protection circuit and an over-temperature protection system for an LED lamp panel of a clothes airing machine. The over-temperature protection circuit comprises a main chip, a temperature sensing module and an LED driving module, the temperature sensing module comprises a thermistor, a comparator, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor; the LED driving module is connected with a power supply and comprises an LED diode group and an LED driving chip; the LED diode group is connected to an FB port of the LED driving chip, and an E / P port of the LED driving chip is connected to a PWM port of the main chip; when the temperature of the LED diode group exceeds a preset temperature, the resistance value of the thermistor is reduced until the output end of the comparator outputs a low level, so that the main chip reduces the terminal voltage of the LED diode group through the LED driving chip; when the temperature of the LED diode group exceeds the preset temperature and then continuously rises, the main chip reduces the terminal voltage of the LED diode group to zero through the LED driving chip; the LED lamp panel has the advantages that partition and secondary over-temperature protection is provided for the LED lamp panel of the clothes airing machine, LED lamp beads are prevented from being damaged, and the service life of illumination is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of electric clothes drying racks, and in particular to an over-temperature protection circuit and system for LED light panels in clothes drying racks, which is used to reduce the risk of overheating caused by heat-generating components such as motors and drying modules in the main unit of the clothes drying rack to the LED light panels. Background Technology

[0002] With the rapid development of intelligent home appliances, smart clothes drying racks have become an essential smart drying device in the home appliance market, especially for urban residents. Currently, smart clothes drying racks on the market integrate multiple functions, including adjustable drying rods, drying, disinfection, lighting, and WiFi.

[0003] For example, the utility model patent with authorization announcement number CN221956396U discloses a drying module and a clothes drying machine. The main body of the clothes drying machine includes a main body module, a drying module and a lighting module. The lighting module is located directly below the main body module, and the drying module is located on both sides below the main body module. The lighting module is a large screen light. The main body module is equipped with a control system, and the lighting module, drying module and control system are electrically connected.

[0004] It is evident that designing the lighting module of a smart clothes drying rack as a full-screen LED light panel has become a market trend and is widely welcomed by consumers. Especially after the advent of designs where the drying rod can be concealed within the ceiling, many consumers are directly using the full-screen lighting of their smart clothes drying racks as ceiling lights for their balconies. Consequently, consumers' demands for the lighting quality of smart clothes drying racks have also increased.

[0005] Many factors affect the lighting quality of smart clothes drying racks, and the ambient temperature of the LED operating environment is one of them. As can be seen from the accompanying drawings in the aforementioned prior art specifications, the LED light panel, motor, and drying module are all located on the main unit. Especially when the LED light panel has a large illumination area, the large amount of heat generated by the motor and drying module can easily cause parts of the LED light panel to yellow or become damaged. This can lead to visible unevenness in the brightness and color temperature of the LED light panel, affecting the user experience and lifespan of the smart clothes drying rack's lighting function. Utility Model Content

[0006] Given that the LED light panel, motor, and drying module of existing smart clothes drying racks are located close together in the main unit, the heat generated by the operation of the motor and drying module causes uneven brightness and color temperature of the LED light panel, affecting the use of the lighting function of the smart clothes drying rack. The technical problem to be solved by this utility model is to provide an over-temperature protection circuit and protection system for the LED light panel of a clothes drying rack, which organically combines the circuit board design and the physical layout of the protection circuit to provide over-temperature protection for the LED light panel.

[0007] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: an over-temperature protection circuit for LED light board of clothes drying rack, including a main chip, a temperature sensing module and an LED driver module;

[0008] The temperature sensing module includes a thermistor, a comparator, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, and a fifteenth resistor. One end of the thermistor is connected to a power supply, and the other end is connected to the fourteenth resistor and then grounded. One end of the fifteenth resistor is connected to a power supply, and the other end is connected to the twelfth resistor and then grounded. The inverting input of the comparator is connected to the node between the thermistor and the fourteenth resistor, and the non-inverting input of the comparator is connected to the node between the fifteenth resistor and the twelfth resistor. The output of the comparator is connected to the PTC port of the main chip through the thirteenth resistor.

[0009] The LED driver module is connected to a power source and includes an LED diode group and an LED driver chip; the LED diode group is connected to the FB port of the LED driver chip, and the E / P port of the LED driver chip is connected to the PWM port of the main chip.

[0010] When the temperature of the LED diode group exceeds the preset temperature, the resistance of the thermistor decreases until the output of the comparator outputs a low level, so that the main chip can adjust the terminal voltage of the LED diode group through the LED driver chip.

[0011] When the temperature of the LED diode group exceeds the preset temperature and continues to rise, the main chip reduces the terminal voltage of the LED diode group to zero through the LED driver chip.

[0012] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the LED driving module further includes a brightness fine-tuning sub-module; the brightness fine-tuning sub-module includes an inductor and a parallel capacitor group; the LED diode group is connected to the power supply in sequence through the parallel capacitor group and the inductor; the node between the inductor and the parallel capacitor group is connected to the GATE port of the LED driving chip;

[0013] When the temperature of the LED diode group fluctuates within a preset temperature range, the LED driver chip fine-tunes the terminal voltage of the LED diode group by controlling the charging and discharging of the inductor and the parallel capacitor group.

[0014] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the brightness fine-tuning submodule further includes a field-effect transistor; the gate of the field-effect transistor is connected to the GATE port of the LED driver chip through a fifth resistor and a first diode connected in parallel, the source of the field-effect transistor is grounded through a third resistor, and the drain of the field-effect transistor is connected to the node between the inductor and the parallel capacitor group.

[0015] When the current of the LED diode group decreases, the GATE port voltage of the LED driver chip increases, the field-effect transistor turns on, and the inductor and the parallel capacitor group discharge to increase the terminal voltage of the LED diode group.

[0016] When the current of the LED diode group increases, the GATE port voltage of the LED driver chip decreases, the field-effect transistor is turned off, and the inductor and the parallel capacitor group are charged to reduce the terminal voltage of the LED diode group.

[0017] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the source of the field-effect transistor is grounded through a third resistor; a first resistor is connected in parallel between the source and the gate of the field-effect transistor;

[0018] The GS / OVP port of the LED driver chip is connected to the node between the source of the field-effect transistor and the third resistor via a second resistor; the GS / OVP port of the LED driver chip is connected to the drain of the field-effect transistor via a fourth resistor and is grounded via a third non-polar capacitor.

[0019] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the parallel capacitor group includes a fifth electrolytic capacitor, a sixth non-polar capacitor and a seventh non-polar capacitor connected in parallel with each other;

[0020] A second diode is connected between the inductor and the parallel capacitor bank. The inductor is connected to the positive terminal of the second diode, and the parallel capacitor bank is connected to the negative terminal of the second diode.

[0021] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the LED driving module further includes a voltage regulator submodule; the voltage regulator submodule includes a first electrolytic capacitor and a second non-polar capacitor connected in parallel; the voltage regulator submodule is connected to the front end of the power supply.

[0022] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the LED diode group is connected to the FB port of the LED driver chip through a sixth resistor.

[0023] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: the E / P port of the LED driver chip is connected to the PWM port of the main chip through the tenth resistor;

[0024] The eleventh resistor is connected in parallel with the fourth non-polar capacitor, with one end grounded and the other end connected to the node between the E / P port and the tenth resistor.

[0025] The preferred technical solution adopted by this utility model to solve the above-mentioned technical problems is: the VCC port of the LED driver chip is connected to the power supply through a seventh resistor;

[0026] One end of the eighth non-polarized capacitor is grounded, and the other end is connected to the node between the VCC port and the seventh resistor; one end of the ninth non-polarized capacitor is grounded, and the other end is connected to the node where the seventh resistor is connected to the power supply.

[0027] Another technical solution adopted by this utility model to solve the above-mentioned technical problems is: an over-temperature protection system for LED light panels of clothes drying racks, including LED light panels, motors, drying modules and over-temperature protection circuits for LED light panels of clothes drying racks;

[0028] The LED light panel is divided into several sub-light panels according to the number of motors and drying modules, and each sub-light panel is positioned close to its corresponding motor or drying module.

[0029] Each of the sub-lamp boards is equipped with a temperature sensing module and an LED driver module, and all the temperature sensing modules and LED driver modules are connected to the corresponding ports of the main chip; the LED diode groups are evenly arranged on their respective sub-lamp boards;

[0030] Each of the temperature sensing modules is located close to its corresponding motor or drying module.

[0031] Compared with the prior art, the advantages of this utility model are: The over-temperature protection circuit for the LED light board of the clothes drying rack provided by this utility model monitors the temperature change of the LED diode group through a temperature sensing module, and controls the terminal voltage of the LED diode group through the path of temperature sensing module-main chip-LED driver module, thereby realizing two-stage over-temperature protection for the LED diode group, namely:

[0032] Level 1 Over-temperature protection: When the temperature of the LED diode group exceeds the preset temperature, the terminal voltage of the LED diode group is reduced; Level 2 Over-temperature protection: When the temperature of the LED diode group continues to rise after exceeding the preset temperature, the terminal voltage of the LED diode group is reduced to zero.

[0033] Furthermore, the over-temperature protection system for the LED light panel of the clothes drying rack provided by this utility model divides the LED light panel into several sub-light panels according to the number and relative distance of heating components such as the motor and drying module. Each sub-light panel is equipped with a temperature sensing module and an LED driver module, thereby realizing zoned over-temperature protection for the LED light panel. This not only improves the sensitivity and accuracy of temperature monitoring, but also provides targeted protection against localized over-temperature of the LED light panel caused by different heating components.

[0034] The over-temperature protection circuit for the clothes drying rack LED light panel provides over-temperature protection from the perspective of circuit design, while the over-temperature protection system for the clothes drying rack LED light panel optimizes over-temperature protection performance from the perspective of module layout. The two complement each other, promptly preventing the LED light panel from being in an over-temperature state for a long time, which could lead to a shortened lifespan or even burnout of the LED beads (i.e., LED diode groups). This reduces the risk of high temperatures caused by the operation of heat-generating components affecting the normal lighting of the LED light panel, extends the lifespan of the LED light panel, and improves the user experience of the clothes drying rack's lighting function. Attached Figure Description

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present invention. Furthermore, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated depictions, and the drawings are not necessarily drawn to scale.

[0036] Figure 1 This is a block diagram of the control system for a smart clothes drying rack in the prior art;

[0037] Figure 2 This is a schematic diagram of the over-temperature protection system for the LED light panel of a clothes drying rack according to a preferred embodiment of the present invention;

[0038] Figure 3 This is a system block diagram of an LED light panel over-temperature protection system for a clothes drying rack according to a preferred embodiment of the present invention.

[0039] Figure 4 The circuit diagram of the over-temperature protection circuit for the LED light board of a clothes drying rack according to a preferred embodiment of this utility model;

[0040] Explanation of reference numerals in the attached drawings: Clothes drying rack main unit 300, clothes drying rack LED light panel over-temperature protection system 200, LED light panel 201, motor 202, drying module 203a, 203b, sub-light panel 201a, 201b, 201c, clothes drying rack LED light panel over-temperature protection circuit 100, temperature sensing module 101, LED driver module 102, brightness fine-tuning sub-module 103, voltage stabilizing sub-module 104. Detailed Implementation

[0041] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0042] In the description of this utility model, it should be noted that the terms "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Similarly, "first" and "second" are only for ease of understanding and have no other directional meaning, and cannot be considered as limitations on this utility model.

[0043] like Figure 1 The diagram shown is a control system block diagram of a smart clothes drying rack in the prior art. Because no overheat protection circuit and protection system for the LED light panel are added, the motor, drying module and LED light panel are independently controlled by the main chip. There is no feedback path with temperature as the control variable between them. After the heat released by the motor and drying module during operation is conducted to the LED light panel, all three continue to operate. This can easily lead to overheating of the LED light panel, uneven brightness and color temperature, damage to the LED beads and shortened service life.

[0044] like Figure 2 The diagram shows the structure of the clothes drying rack LED light panel over-temperature protection system 200 provided in this embodiment. It is installed inside the clothes drying rack main unit 300 and includes an LED light panel 201, a motor 202, two drying modules 203a and 203b, and an LED light panel over-temperature protection circuit. The LED light panel 201 is a full-screen LED light panel. The motor 202 is located in the middle of the main unit 300. The two drying modules 203a and 203b are located at both ends of the main unit 300 and on both sides of the LED light panel 201, respectively.

[0045] The LED light panel 201 is divided into three sub-light panels 201a, 201b, and 201c according to the number of motors 202 and drying modules 203a and 203b. Each sub-light panel 201a, 201b, and 201c is positioned close to its corresponding motor 202 or drying module 203a or 203b. That is, the middle part of the LED light panel 201 is sub-light panel 201a, which is close to the motor 202; the left part of the LED light panel 201 is sub-light panel 201b, which is close to the drying module 203a; and the right part of the LED light panel 201 is sub-light panel 201c, which is close to the drying module 203b.

[0046] like Figure 4 The diagram shown is of the over-temperature protection circuit 100 for the LED light panel of the clothes drying rack provided in this embodiment, including a main chip U1, a temperature sensing module 101, and an LED driver module 102. The LED driver module 102 includes LED diode groups LED1, LED2, and LED3, and the LED driver chip U1.

[0047] Corresponding to the over-temperature protection system 200 for the LED light panel of the clothes drying rack, there is only one main chip U1, but each sub-light panel 201a, 201b, and 201c is equipped with a temperature sensing module 101 and an LED driver module 102. The three temperature sensing modules 101 and the three LED driver modules 102 are respectively connected to the corresponding ports of the main chip U1. The LED diode groups LED1, LED2, and LED3 are evenly arranged on their corresponding sub-light panels 201a, 201b, and 201c.

[0048] It should be noted that the actual number of LEDs in the LED diode group is set according to actual needs. Due to space limitations of the circuit diagram, the figure shows a simplified illustration with three LEDs, which does not mean that each LED driver module 102 includes only three LEDs.

[0049] like Figure 2 As shown, each temperature sensing module 101 is positioned close to its corresponding motor 202 or drying modules 203a and 203b. Specifically, the temperature sensing module 101 of sub-lamp board 201a is positioned close to the motor 202, the temperature sensing module 101 of sub-lamp board 201b is positioned close to the drying module 203a, and the temperature sensing module 101 of sub-lamp board 201c is positioned close to the drying module 203b.

[0050] It should be noted that in other embodiments, the number and position of the motor and drying module may be different from those in this embodiment. However, this utility model does not limit the number and position of the motor and drying module. Therefore, the LED light board is divided into several sub-light boards according to the number of motors and drying modules. Each sub-light board is located close to its corresponding motor or drying module. Each sub-light board is equipped with a temperature sensing module and an LED driving module. All temperature sensing modules and LED driving modules are connected to the corresponding ports of the main chip. LED diode groups are evenly arranged on their corresponding sub-light boards. Each temperature sensing module is located close to its corresponding motor or drying module.

[0051] The following is a detailed look at the over-temperature protection circuit 100 for the LED light panel of the clothes drying rack:

[0052] like Figure 4 As shown, the temperature sensing module 101 includes a thermistor RT1, a comparator Q2, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a fifteenth resistor R15. One end of the thermistor RT1 is connected to a 12V DC power supply, and the other end is connected to the fourteenth resistor R14 and then grounded (GND). One end of the fifteenth resistor R15 is connected to a 12V DC power supply, and the other end is connected to the twelfth resistor R12 and then grounded (GND). The inverting input (pin 2) of the comparator Q2 is connected to the node between the thermistor RT1 and the fourteenth resistor R14, and the non-inverting input (pin 3) of the comparator Q2 is connected to the node between the fifteenth resistor R15 and the twelfth resistor R12. The output (pin 1) of the comparator Q2 is connected to the PTC port (port 3) of the main chip U2 through the thirteenth resistor R13.

[0053] The LED driver module 102 is connected to a 24V DC power supply and includes LED diode groups LED1, LED2, and LED3 and LED driver chip U1. LED diode groups LED1, LED2, and LED3 are connected to the FB port (port 6) of LED driver chip U1, and the E / P port (port 4) of LED driver chip U1 is connected to the PWM port (port 2) of the main chip.

[0054] When the LED diode group LED1, LED2, and LED3 are within the preset normal temperature range, the thermistor RT1 maintains a high resistance, the inverting input terminal (pin 2) of comparator Q2 receives a low level, and the output terminal (pin 1) outputs a high level, meaning the input to the main chip's PTC port (port 3) is high. At this time, the LED diode group LED1, LED2, and LED3 maintain normal operation, and the LED light board 201 maintains normal brightness.

[0055] When the temperature of the corresponding LED diode groups LED1, LED2, and LED3 on a certain sub-lamp board 201a, 201b, or 201c exceeds the preset temperature, the resistance of the thermistor RT1 in the corresponding temperature sensing module 101 decreases. The input level at the inverting input terminal (pin 2) of comparator Q2 increases accordingly until it exceeds the level at the non-inverting input terminal (pin 3). The output terminal (pin 1) of comparator Q2 then outputs a low level, causing the PTC port (port 3) of the main chip U2 to input a low level. At this time, the PWM port (port 2) of the main chip U2 sends a signal to the E / P port (port 4) of the LED driver chip U1. The FB port (port 6) of the LED driver chip U1 lowers the terminal voltage of the LED diode groups LED1, LED2, and LED3, thereby reducing the brightness of the lamp boards 201a, 201b, and 201c.

[0056] When the temperature of the corresponding LED diode groups LED1, LED2, and LED3 on the LED boards 201a, 201b, and 201c exceeds the preset temperature and continues to rise, the PWM port (port 2) of the main chip U2 sends a signal to the E / P port (port 4) of the LED driver chip U1. The FB port (port 6) of the LED driver chip U1 then reduces the terminal voltage of the LED diode groups LED1, LED2, and LED3 to zero, thereby turning off the LED boards 201a, 201b, and 201c. This prevents the LED boards 201 from being in an overheated state for a long time, which could shorten the lifespan of the LED beads (i.e., the LED diode groups) or even cause them to burn out.

[0057] Thus, combined Figure 3 As can be seen, the over-temperature protection circuit for the LED light board of the clothes drying rack provided by this utility model monitors the temperature change of the LED diode group through a temperature sensing module, and controls the terminal voltage of the LED diode group through the path of temperature sensing module-main chip-LED driver module, thereby realizing two-stage over-temperature protection for the LED diode group, namely:

[0058] Level 1 Over-temperature protection: When the temperature of the LED diode group exceeds the preset temperature, the terminal voltage of the LED diode group is reduced; Level 2 Over-temperature protection: When the temperature of the LED diode group continues to rise after exceeding the preset temperature, the terminal voltage of the LED diode group is reduced to zero.

[0059] Furthermore, the over-temperature protection system for the LED light panel of the clothes drying rack provided by this utility model divides the LED light panel into several sub-light panels according to the number and relative distance of heating components such as the motor and drying module. Each sub-light panel is equipped with a temperature sensing module and an LED driver module, thereby realizing zoned over-temperature protection for the LED light panel. This not only improves the sensitivity and accuracy of temperature monitoring, but also provides targeted protection against localized over-temperature of the LED light panel caused by different heating components.

[0060] The over-temperature protection circuit for the clothes drying rack LED light panel provides over-temperature protection from the perspective of circuit design, while the over-temperature protection system for the clothes drying rack LED light panel optimizes over-temperature protection performance from the perspective of module layout. The two complement each other, promptly preventing the LED light panel from being in an over-temperature state for a long time, which could lead to a shortened lifespan or even burnout of the LED beads (i.e., LED diode groups). This reduces the risk of high temperatures caused by the operation of heat-generating components affecting the normal lighting of the LED light panel, extends the lifespan of the LED light panel, and improves the user experience of the clothes drying rack's lighting function.

[0061] Furthermore, such as Figure 4 As shown, the LED driver module 102 also includes a brightness fine-tuning submodule 103, which includes an inductor L1 and a parallel capacitor bank. Preferably, in this embodiment, the parallel capacitor bank includes a fifth electrolytic capacitor C5, a sixth non-polar capacitor C6, and a seventh non-polar capacitor C7 connected in parallel. The LED diode groups LED1, LED2, and LED3 are connected to a 24V DC power supply sequentially via the parallel capacitor bank and the inductor L1. The node between the inductor L1 and the parallel capacitor bank is connected to the GATE port (pin 3) of the LED driver chip U1.

[0062] When the temperature of LED diode group LED1, LED2, and LED3 fluctuates within the preset temperature range, the current flowing through LED diode group LED1, LED2, and LED3 fluctuates accordingly. After receiving the signal of this current fluctuation at the FB port (port 6) of LED driver chip U1, the GATE port (pin 3) controls the charging and discharging of inductor L1 and parallel capacitor group to fine-tune the terminal voltage of LED diode group LED1, LED2, and LED3, thereby adjusting their brightness and reducing the flickering and uneven brightness of LED light board 201.

[0063] Preferably, such as Figure 4 As shown, the brightness fine-tuning submodule 103 also includes a field-effect transistor (FET) Q1. The gate of FET Q1 is connected to the GATE port (pin 3) of the LED driver chip U1 via a fifth resistor R5 and a first diode D1 connected in parallel. The source of FET Q1 is grounded via a third resistor R3. The drain of FET Q1 is connected to the node between the inductor L1 and the parallel capacitor bank. In this embodiment, a second diode D2 is connected between the inductor L1 and the parallel capacitor bank. The inductor L1 is connected to the anode of the second diode D2, and the parallel capacitor bank is connected to the cathode of the second diode D2. Therefore, the drain of FET Q1 is connected to the node between the anodes of the inductor L1 and the second diode D2 to control the direction of the charging and discharging current of the inductor L1 and the parallel capacitor bank.

[0064] When the current flowing through the LED diode group LED1, LED2, and LED3 decreases, the voltage at the GATE port (port 3) of the LED driver chip U1 increases, the field-effect transistor Q1 turns on, and the inductor L1 and the parallel capacitor group discharge, thereby increasing the terminal voltage of the LED diode group LED1, LED2, and LED3, and their brightness increases accordingly.

[0065] Conversely, when the current flowing through the LED diode group LED1, LED2, and LED3 increases, the voltage at the GATE port (port 3) of the LED driver chip U1 decreases, the field-effect transistor Q1 is turned off, and the inductor L1 and the parallel capacitor group are charged to reduce the terminal voltage of the LED diode group LED1, LED2, and LED3, and their brightness decreases accordingly.

[0066] Therefore, the LED driver chip U1, in conjunction with the field-effect transistor Q1, monitors the current of the LED diode group LED1, LED2, and LED3, controls the charging and discharging of the inductor L1 and the parallel capacitor group, and adjusts the terminal voltage of the LED diode group LED1, LED2, and LED3, forming a negative feedback closed loop. This provides instantaneous adjustment and balance for situations where the LED light board 201, although not overheated, experiences uneven brightness and flickering due to temperature changes. This function also serves as a form of overheat protection, namely temperature fluctuation balancing protection when the LED light board 201 does not exceed the preset temperature. This also extends the lifespan of the LED diode group and the LED light board, improving the user experience of the clothes drying rack's lighting function.

[0067] In this embodiment, LED diode groups LED1, LED2, and LED3 are connected to the FB port (port 6) of LED driver chip U1 via a sixth resistor R6. The sixth resistor R6 serves as the current sampling resistor for LED diode groups LED1, LED2, and LED3, converting the current flowing through LED diode groups LED1, LED2, and LED3 into a voltage modulus input to the FB port (port 6).

[0068] Furthermore, the source of the field-effect transistor Q1 is grounded via the third resistor R3, and a first resistor R1 is connected in parallel between the source and gate of the field-effect transistor Q1. The GS / OVP port (port 1) of the LED driver chip U1 is connected to the node between the source of the field-effect transistor Q1 and the third resistor R3 via the second resistor R2. The GS / OVP port (port 1) of the LED driver chip U1 is connected to the drain of the field-effect transistor Q1 via the fourth resistor R4, and is grounded via the third non-polarized capacitor C3.

[0069] The LED driver module 102 also includes a voltage regulator submodule 104. The voltage regulator submodule 104 includes a first electrolytic capacitor C1 and a second non-polar capacitor C2 connected in parallel. The voltage regulator submodule 104 is connected to the front end of a 24V DC power supply. That is, the 24V DC power supply is first regulated by the voltage regulator submodule 104 before being input to the LED driver module 102.

[0070] The E / P port (port 4) of the LED driver chip U1 is connected to the PWM port (port 3) of the main chip U1 via the tenth resistor R10. The eleventh resistor R11 is connected in parallel with the fourth non-polar capacitor layer to form a parallel RC voltage regulation circuit. One end is grounded to GND, and the other end is connected to the node between the E / P port (port 4) and the tenth resistor R10.

[0071] The VCC port (port 5) of the LED driver chip U1 is connected to a 12V DC power supply via the seventh resistor R7 to power the LED driver chip U1. One end of the eighth non-polarized capacitor C8 is grounded to GND, and the other end is connected to the node between the VCC port (port 5) and the seventh resistor R7. One end of the ninth non-polarized capacitor C9 is grounded to GND, and the other end is connected to the node where the seventh resistor R7 is connected to the 12V DC power supply.

[0072] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it may not be further defined and explained in subsequent figures.

[0073] The above describes the over-temperature protection circuit and system for the LED light panel of the clothes drying rack provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand this utility model and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. Over-temperature protection circuit for LED light board of clothes drying rack, characterized in that: Includes the main chip, temperature sensing module, and LED driver module; The temperature sensing module includes a thermistor, a comparator, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, and a fifteenth resistor. One end of the thermistor is connected to a power supply, and the other end is connected to the fourteenth resistor and then grounded. One end of the fifteenth resistor is connected to a power supply, and the other end is connected to the twelfth resistor and then grounded. The inverting input of the comparator is connected to the node between the thermistor and the fourteenth resistor, and the non-inverting input of the comparator is connected to the node between the fifteenth resistor and the twelfth resistor. The output of the comparator is connected to the PTC port of the main chip through the thirteenth resistor. The LED driver module is connected to a power source and includes an LED diode group and an LED driver chip; the LED diode group is connected to the FB port of the LED driver chip, and the E / P port of the LED driver chip is connected to the PWM port of the main chip. When the temperature of the LED diode group exceeds the preset temperature, the resistance of the thermistor decreases until the output of the comparator outputs a low level, so that the main chip can adjust the terminal voltage of the LED diode group through the LED driver chip. When the temperature of the LED diode group exceeds the preset temperature and continues to rise, the main chip reduces the terminal voltage of the LED diode group to zero through the LED driver chip.

2. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 1, characterized in that: The LED driver module further includes a brightness fine-tuning submodule; the brightness fine-tuning submodule includes an inductor and a parallel capacitor bank; the LED diode bank is connected to the power supply in sequence via the parallel capacitor bank and the inductor; the node between the inductor and the parallel capacitor bank is connected to the GATE port of the LED driver chip; When the temperature of the LED diode group fluctuates within a preset temperature range, the LED driver chip fine-tunes the terminal voltage of the LED diode group by controlling the charging and discharging of the inductor and the parallel capacitor group.

3. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 2, characterized in that: The brightness fine-tuning submodule also includes a field-effect transistor; the gate of the field-effect transistor is connected to the GATE port of the LED driver chip through a fifth resistor and a first diode in parallel, the source of the field-effect transistor is grounded through a third resistor, and the drain of the field-effect transistor is connected to the node between the inductor and the parallel capacitor bank. When the current of the LED diode group decreases, the GATE port voltage of the LED driver chip increases, the field-effect transistor turns on, and the inductor and the parallel capacitor group discharge to increase the terminal voltage of the LED diode group. When the current of the LED diode group increases, the GATE port voltage of the LED driver chip decreases, the field-effect transistor is turned off, and the inductor and the parallel capacitor group are charged to reduce the terminal voltage of the LED diode group.

4. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 3, characterized in that: The source of the field-effect transistor is grounded via a third resistor; a first resistor is connected in parallel between the source and the gate of the field-effect transistor. The GS / OVP port of the LED driver chip is connected to the node between the source of the field-effect transistor and the third resistor via a second resistor; the GS / OVP port of the LED driver chip is connected to the drain of the field-effect transistor via a fourth resistor and is grounded via a third non-polar capacitor.

5. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 2, characterized in that: The parallel capacitor bank includes a fifth electrolytic capacitor, a sixth non-polar capacitor, and a seventh non-polar capacitor connected in parallel. A second diode is connected between the inductor and the parallel capacitor bank. The inductor is connected to the positive terminal of the second diode, and the parallel capacitor bank is connected to the negative terminal of the second diode.

6. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 1, characterized in that: The LED driver module also includes a voltage regulator submodule; the voltage regulator submodule includes a first electrolytic capacitor and a second non-polar capacitor connected in parallel; the voltage regulator submodule is connected to the front end of the power supply.

7. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 1, characterized in that: The LED diode group is connected to the FB port of the LED driver chip via a sixth resistor.

8. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 1, characterized in that: The E / P port of the LED driver chip is connected to the PWM port of the main chip via a tenth resistor; The eleventh resistor is connected in parallel with the fourth non-polar capacitor, with one end grounded and the other end connected to the node between the E / P port and the tenth resistor.

9. The over-temperature protection circuit for the LED light board of the clothes drying rack according to claim 1, characterized in that: The VCC port of the LED driver chip is connected to the power supply via a seventh resistor. One end of the eighth non-polar capacitor is grounded, and the other end is connected to the node between the VCC port and the seventh resistor; One end of the ninth non-polar capacitor is grounded, and the other end is connected to the node where the seventh resistor is connected to the power supply.

10. An over-temperature protection system for LED light panels on a clothes drying rack, characterized in that: Includes an LED light panel, a motor, a drying module, and an over-temperature protection circuit for the LED light panel of the clothes dryer as described in any one of claims 1-9; The LED light panel is divided into several sub-light panels according to the number of motors and drying modules, and each sub-light panel is positioned close to its corresponding motor or drying module. Each of the sub-lamp boards is equipped with a temperature sensing module and an LED driver module, and all the temperature sensing modules and LED driver modules are connected to the corresponding ports of the main chip; the LED diode groups are evenly arranged on their respective sub-lamp boards; Each of the temperature sensing modules is located close to its corresponding motor or drying module.

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