A multi-parallel LED lamp string safety control system

Abstract

The present invention relates to a safety control system for multiple parallel LED light strings. The first end of an LED drive circuit is connected to the first end of each group of LED light strings, the second end of each group of LED light strings is connected to the first end of a corresponding first voltage detection circuit, the second end of each first voltage detection circuit is connected to the second end of the LED drive circuit, and the third end of each first voltage detection circuit is connected to a processor. The second end of the LED drive circuit is connected to a first ground point via the voltage divider circuit, and the processor is connected to the LED drive circuit. The processor obtains the first detection voltage of each first voltage detection circuit. If a first detection voltage is the voltage across the voltage divider circuit, it indicates that the LED light string corresponding to the first voltage detection circuit has an open circuit fault; the processor controls the LED drive circuit to reduce the output current. The present invention can detect open circuit faults in LED light strings, thereby adjusting the drive current in a timely manner to avoid damage to the LED light strings.

Description

Technical Field

[0001] The present invention relates to the field of LED control, and more particularly to a safety control system for multiple parallel LED light strings. Background Art

[0002] Multi-parallel LED light strings consist of multiple groups of LED strings, each of which includes multiple LED beads connected in series. When driving these multi-parallel LED strings, the LED driver circuit drives them as a whole, providing operating current, and cannot control the operating current of individual LED strings individually. Due to this driving mode, if a single LED string fails, such as an open circuit or short circuit, the current in other LED strings will increase while the total LED driver output current remains unchanged, potentially causing overcurrent damage and damaging the LED strings. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a safety control system for multiple parallel LED light strings.

[0004] The technical solution adopted by the present invention to solve its technical problem is: constructing a multi-parallel LED light string safety control system, including an LED driving circuit, at least two groups of LED light strings, at least two first voltage detection circuits, a voltage divider circuit and a processor, each of the LED light strings corresponding to one first voltage detection circuit, and the LED light strings including at least two LED lamp beads connected in series;

[0005] The LED driving circuit is used to drive the LED light strings, and the input end of the LED driving circuit is connected to the power supply VIN; the first end of the LED driving circuit is connected to the first end of each group of the LED light strings, the second end of each group of the LED light strings is connected to the first end of the corresponding first voltage detection circuit, the second end of each first voltage detection circuit is connected to the second end of the LED driving circuit, and the third end of each first voltage detection circuit is connected to the processor; the second end of the LED driving circuit is connected to the first ground point through the voltage divider circuit; the processor is connected to the LED driving circuit; and the voltage divider circuit is connected to the processor;

[0006] The processor obtains the voltage across the voltage divider circuit; the processor obtains the first detection voltage of each first voltage detection circuit. If a certain first detection voltage is the voltage across the voltage divider circuit, it indicates that the LED light string corresponding to the first voltage detection circuit has an open circuit fault; the processor controls the LED drive circuit to reduce the output current.

[0007] Furthermore, in the multi-parallel LED light string safety control system of the present invention, the first voltage detection circuit includes a first resistor R1 and a second resistor R2;

[0008] The first end of the first resistor R1 is connected to the first end of the second resistor R2, the connection point of the first resistor R1 and the second resistor R2 is the first end of the first voltage detection circuit, the second end of the first resistor R1 is the second end of the first voltage detection circuit, and the second end of the second resistor R2 is the third end of the first voltage detection circuit.

[0009] Furthermore, in the multi-parallel LED light string safety control system of the present invention, the first voltage detection circuit further includes a first capacitor C1, and the second end of the second resistor R2 is connected to the first ground point through the first capacitor C1.

[0010] Furthermore, in the multi-parallel LED light string safety control system described in the present invention, the voltage divider circuit includes a third resistor R3 and a fourth resistor R4, the third resistor R3 and the fourth resistor R4 are connected in parallel, the first end after parallel connection is connected to the second end of the LED drive circuit, and the second end after parallel connection is connected to the first grounding point.

[0011] Furthermore, in the multi-parallel LED light string safety control system described in the present invention, the voltage divider circuit also includes a diode D1, the positive electrode of the diode D1 is connected to the second end of the LED drive circuit, and the negative electrode of the diode D1 is connected to the first ground point.

[0012] Furthermore, the multi-parallel LED light string safety control system of the present invention further includes a second voltage detection circuit, wherein a first end of the second voltage detection circuit is connected to a first end of each of the LED light strings, and a second end of the second voltage detection circuit is connected to the processor;

[0013] The processor obtains the second detection voltage of the second voltage detection circuit. If the second detection voltage is not within a preset voltage range, it indicates that a short circuit fault occurs in the LED light string. The processor controls the LED driving circuit to stop driving the LED light string.

[0014] Furthermore, in the multi-parallel LED light string safety control system of the present invention, the second voltage detection circuit includes a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7;

[0015] The first end of the fifth resistor R5 is the first end of the second voltage detection circuit, the second end of the fifth resistor R5 is respectively connected to the first end of the sixth resistor R6 and the first end of the seventh resistor R7, the second end of the sixth resistor R6 is connected to the first ground point, and the second end of the seventh resistor R7 is the second end of the second voltage detection circuit.

[0016] Furthermore, the multi-parallel LED light string safety control system of the present invention further includes a second capacitor C2, and two ends of the second capacitor C2 are respectively connected to the second end of the sixth resistor R6 and the second end of the seventh resistor R7.

[0017] Furthermore, the multi-parallel LED light string safety control system of the present invention further includes a third voltage detection circuit, wherein a first end of the third voltage detection circuit is connected to the power supply VIN, a second end of the third voltage detection circuit is connected to the processor, and a third end of the third voltage detection circuit is connected to the first ground point;

[0018] The processor obtains a third detection voltage of the third voltage detection circuit. If the third detection voltage is greater than a first preset voltage, an overvoltage fault occurs in the power supply VIN, and the processor executes an overvoltage protection strategy. If the third detection voltage is less than a second preset voltage, an undervoltage fault occurs in the power supply VIN, and the processor executes an undervoltage protection strategy. The first preset voltage is greater than the second preset voltage.

[0019] Furthermore, in the multi-parallel LED light string safety control system of the present invention, the third voltage detection circuit includes an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10;

[0020] The first end of the eighth resistor R8 is the first end of the third voltage detection circuit, the second end of the eighth resistor R8 is respectively connected to the first end of the ninth resistor R9 and the first end of the tenth resistor R10, the second end of the ninth resistor R9 is the second end of the third voltage detection circuit, and the second end of the tenth resistor R10 is the third end of the third voltage detection circuit.

[0021] Furthermore, in the multi-parallel LED light string safety control system of the present invention, the third voltage detection circuit also includes a third capacitor C3, and the two ends of the capacitor C3 are respectively connected to the second end of the ninth resistor R9 and the second end of the tenth resistor R10.

[0022] Furthermore, the multi-parallel LED light string safety control system of the present invention further includes a switch circuit, wherein a first end of the switch circuit is connected to the processor, a second end of the switch circuit is connected to a first ground point, and a third end of the switch circuit is connected to a second ground point;

[0023] When the processor controls the switch circuit to be turned on, the first grounding point and the second grounding point are connected; when the processor controls the switch circuit to be turned off, the first grounding point and the second grounding point are disconnected.

[0024] Furthermore, in the multi-parallel LED light string safety control system of the present invention, the switch circuit includes a MOS transistor Q1, an eleventh resistor R11, a twelfth resistor R12 and a thirteenth resistor R13;

[0025] The gate of the MOS transistor Q1 is connected to the processor through the eleventh resistor R11, the gate of the MOS transistor Q1 is connected to the source of the MOS transistor Q1 through the twelfth resistor R12, the source of the MOS transistor Q1 is connected to the second ground point through the thirteenth resistor R13; and the drain of the MOS transistor Q1 is connected to the first ground point.

[0026] Furthermore, the multi-parallel LED light string safety control system of the present invention further includes a fourteenth resistor R14 and a fourth capacitor C4, and the LED driving circuit includes a driving chip U1;

[0027] A first end of the fourteenth resistor R14 is connected to the feedback input pin FB of the driver chip U1 , a second end of the fourteenth resistor R14 is connected to the processor, and a second end of the fourteenth resistor R14 is connected to the first ground point via the fourth capacitor C4 .

[0028] Furthermore, in the multi-parallel LED light string safety control system described in the present invention, the LED driving circuit includes a driving chip U1 and an adjustable resistor, and the current sampling pin CS of the driving chip U1 is connected to the first ground point through the adjustable resistor; the output current value of the LED driving circuit is adjusted by adjusting the resistance value of the adjustable resistor.

[0029] Furthermore, the multi-parallel LED light string safety control system of the present invention further includes a feedback circuit connected to the processor for feeding back fault information.

[0030] The implementation of a multi-parallel LED light string safety control system of the present invention has the following beneficial effects: the present invention can detect open circuit faults of LED light strings, thereby adjusting the driving current in time to avoid damage to the LED light strings and achieve safe operation of the multi-parallel LED light strings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0032] Figure 1 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0033] Figure 2 is a circuit diagram of a first voltage detection circuit 30 provided in an embodiment of the present invention;

[0034] Figure 3 is a circuit diagram of a voltage divider circuit 40 provided in an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0036] Figure 5 is a circuit diagram of a second voltage detection circuit 60 provided in an embodiment of the present invention;

[0037] Figure 6 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0038] Figure 7 is a circuit diagram of a third voltage detection circuit 70 provided in an embodiment of the present invention;

[0039] Figure 8 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0040] Figure 9 is a circuit diagram of a switch circuit 80 provided in an embodiment of the present invention;

[0041] Figure 10 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0042] Figure 11 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0043] Figure 12 is a circuit diagram of an adjustable resistor 90 provided in an embodiment of the present invention;

[0044] Figure 13 Schematic diagram of a multi-parallel LED light string safety control system provided by an embodiment of the present invention;

[0045] Figure 14 is a circuit diagram of an LED driving circuit 10 provided in an embodiment of the present invention;

[0046] Figure 15 1 is a circuit diagram of an LED driving circuit 10 provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0048] In a preferred embodiment, reference Figure 1 The multi-parallel LED light string safety control system of this embodiment includes an LED driving circuit 10, at least two groups of LED light strings 20, at least two first voltage detection circuits 30, a voltage divider circuit 40 and a processor 50. Each LED light string 20 corresponds to a first voltage detection circuit 30, and the LED light string 20 includes at least two LED lamp beads connected in series.

[0049] The LED driver circuit 10 is used to drive the LED light strings 20. The input end of the LED driver circuit 10 is connected to the power supply VIN. The first end of the LED driver circuit 10 is connected to the first end of each group of LED light strings 20. The second end of each group of LED light strings 20 is connected to the first end of the corresponding first voltage detection circuit 30. The second end of each first voltage detection circuit 30 is connected to the second end of the LED driver circuit 10. The third end of each first voltage detection circuit 30 is connected to the processor 50. The second end of the LED driver circuit 10 is connected to a first ground point (denoted as GND1 in the figure) via a voltage divider circuit 40. The processor 50 is connected to the LED driver circuit 10. The voltage divider circuit 40 is connected to the processor 50. The operating principle of the safety control system of this embodiment is as follows: the processor 50 obtains the voltage across the voltage divider circuit 40. The LED driver circuit 10 converts the power supply VIN into a drive signal to drive each group of LED light strings 20. The first voltage detection circuit 30 collects the current divided voltage of the corresponding LED light string 20, i.e., the first detection voltage, and sends the first detection voltage to the processor 50. After obtaining the first detection voltage of each first voltage detection circuit 30, the processor 50 determines whether the first detection voltage is equal to the voltage across the voltage divider circuit 40. If a first detection voltage is equal to the voltage across the voltage divider circuit 40, it indicates that the LED light string 20 corresponding to the first voltage detection circuit 30 has an open circuit fault. The processor 50 directly detects the voltage across the voltage divider circuit 40 through the first voltage detection circuit 30. When an LED light string 20 has an open circuit fault, the processor 50 controls the LED driver circuit 10 to reduce the output current to prevent overcurrent in other LED light strings 20 that have not experienced an open circuit fault, thereby preventing damage to the LED light strings 20.

[0050] This embodiment can detect an open circuit fault of an LED light string, thereby adjusting the driving current in a timely manner to avoid damage to the LED light string and achieve safe operation of multiple parallel LED light strings.

[0051] In some embodiments of the multi-parallel LED light string safety control system, reference Figure 2The first voltage detection circuit 30 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the first end of the second resistor R2. The connection point between the first resistor R1 and the second resistor R2 is the first end of the first voltage detection circuit 30. The second end of the first resistor R1 is the second end of the first voltage detection circuit 30. The second end of the second resistor R2 is the third end of the first voltage detection circuit 30. Optionally, the first voltage detection circuit 30 further includes a first capacitor C1. The second end of the second resistor R2 is connected to the first ground point via the first capacitor C1.

[0052] In some embodiments of the multi-parallel LED light string safety control system, reference Figure 3 The voltage divider circuit 40 includes a third resistor R3 and a fourth resistor R4. The third resistor R3 and the fourth resistor R4 are connected in parallel, with a first end of the parallel connection connected to the second end of the LED driver circuit 10 and a second end of the parallel connection connected to the first ground point. Alternatively, the voltage divider circuit 40 further includes a diode D1, with an anode of the diode D1 connected to the second end of the LED driver circuit 10 and a cathode of the diode D1 connected to the first ground point.

[0053] refer to Figure 4 In some embodiments, the multi-parallel LED light string safety control system further includes a second voltage detection circuit 60 , wherein a first end of the second voltage detection circuit 60 is connected to a first end of each LED light string 20 , and a second end of the second voltage detection circuit 60 is connected to the processor 50 .

[0054] The operating principle of this safety control system is as follows: Under normal operation, each LED in the LED light string 20 experiences a certain voltage drop. If one or more LEDs experience a short circuit, the voltage drop changes accordingly, causing the second detection voltage of the second voltage detection circuit 60 to change. After obtaining the second detection voltage from the second voltage detection circuit 60, the processor 50 determines whether the second detection voltage is within a preset voltage range. If the second detection voltage is within the preset voltage range, the LED light string 20 is operating normally and has not experienced a short circuit. If the second detection voltage is not within the preset voltage range, the LED light string 20 has experienced a short circuit, and the processor 50 controls the LED driver circuit 10 to stop driving the LED light string 20.

[0055] This embodiment can detect whether a short circuit fault occurs in the LED light string 20, and can promptly control the LED driving circuit 10 to stop working when a short circuit fault occurs, thereby preventing the LED lamp beads from being damaged.

[0056] In some embodiments of the multi-parallel LED light string safety control system, reference Figure 5The second voltage detection circuit 60 includes a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The first end of the fifth resistor R5 serves as the first end of the second voltage detection circuit 60. The second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6 and the first end of the seventh resistor R7, respectively. The second end of the sixth resistor R6 is connected to the first ground point. The second end of the seventh resistor R7 serves as the second end of the second voltage detection circuit 60. Optionally, some embodiments of the multi-parallel LED light string safety control system further include a second capacitor C2, the two ends of the second capacitor C2 being connected to the second end of the sixth resistor R6 and the second end of the seventh resistor R7, respectively.

[0057] refer to Figure 6 In some embodiments, the multi-parallel LED light string safety control system further includes a third voltage detection circuit 70, a first end of the third voltage detection circuit 70 is connected to the power supply VIN, a second end of the third voltage detection circuit 70 is connected to the processor 50, and a third end of the third voltage detection circuit 70 is connected to the first ground point.

[0058] The operating principle of this safety control system is as follows: the processor 50 obtains the third detection voltage from the third voltage detection circuit 70. If the third detection voltage is greater than a first preset voltage, an overvoltage fault has occurred in the power supply VIN, and the processor 50 executes an overvoltage protection strategy. If the third detection voltage is less than a second preset voltage, an undervoltage fault has occurred in the power supply VIN, and the processor 50 executes an undervoltage protection strategy. The first preset voltage is greater than the second preset voltage.

[0059] This embodiment can monitor whether the power supply VIN is within a safe range, thereby preventing circuit damage caused by power supply voltage fluctuations.

[0060] In some embodiments of the multi-parallel LED light string safety control system, reference Figure 7 The third voltage detection circuit 70 includes an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10. The first end of the eighth resistor R8 serves as the first end of the third voltage detection circuit 70. The second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9 and the first end of the tenth resistor R10, respectively. The second end of the ninth resistor R9 serves as the second end of the third voltage detection circuit 70. The second end of the tenth resistor R10 serves as the third end of the third voltage detection circuit 70. Optionally, the third voltage detection circuit 70 further includes a third capacitor C3, the two ends of which are connected to the second end of the ninth resistor R9 and the second end of the tenth resistor R10, respectively.

[0061] Some embodiments of the multi-parallel LED light string safety control system further include a switch circuit 80, referring to Figure 8The first end of the switch circuit 80 is connected to the processor 50, the second end of the switch circuit 80 is connected to the first ground point, and the third end of the switch circuit 80 is connected to the second ground point, represented by GND2 in the figure. The first ground point and the second ground point are single-point ground points. When the processor 50 controls the switch circuit 80 to be turned on, the first ground point and the second ground point are connected. When the processor 50 controls the switch circuit 80 to be turned off, the first ground point and the second ground point are disconnected. When the switch circuit 80 is turned off, the entire LED light string safety control system is powered off, and the standby power consumption is reduced to zero, thereby maximizing energy conservation.

[0062] In some embodiments of the multi-parallel LED light string safety control system, reference Figure 9 The switching circuit 80 includes a MOS transistor Q1, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13. The gate of the MOS transistor Q1 is connected to the processor 50 via the eleventh resistor R11. The gate of the MOS transistor Q1 is connected to the source of the MOS transistor Q1 via the twelfth resistor R12. The source of the MOS transistor Q1 is connected to the second ground point via the thirteenth resistor R13. The drain of the MOS transistor Q1 is connected to the first ground point. When the processor 50 controls the MOS transistor Q1 to be turned on, the first ground point and the second ground point are connected. When the processor 50 controls the MOS transistor Q1 to be turned off, the first ground point and the second ground point are disconnected. When the MOS transistor Q1 is turned off, the entire LED light string safety control system is powered off, and the standby power consumption is reduced to zero, thereby maximizing energy conservation.

[0063] refer to Figure 10 In some embodiments, the multi-parallel LED light string safety control system further includes a fourteenth resistor R14 and a fourth capacitor C4. The LED driver circuit 10 includes a driver chip U1. A first end of the fourteenth resistor R14 is connected to a feedback input pin FB of the driver chip U1. A second end of the fourteenth resistor R14 is connected to a processor 50. A second end of the fourteenth resistor R14 is connected to a first ground point via the fourth capacitor C4. The processor 50 obtains a feedback voltage from the feedback input pin FB of the driver chip U1 and determines whether the feedback voltage is normal.

[0064] In some embodiments of the multi-parallel LED light string safety control system, reference Figure 11 The LED driver circuit 10 includes a driver chip U1 and an adjustable resistor 90. The current sampling pin CS of the driver chip U1 is connected to a first ground point via the adjustable resistor 90. The output current of the LED driver circuit 10 is adjusted by adjusting the resistance value of the adjustable resistor 90. To reduce the output current of the LED driver circuit 10, the resistance value of the adjustable resistor 90 is increased; to increase the output current of the LED driver circuit 10, the resistance value of the adjustable resistor 90 is decreased.

[0065] Alternatively, the adjustable resistor 90 may be a sliding rheostat, and the output current value of the LED driving circuit 10 can be adjusted by adjusting the resistance value of the sliding rheostat.

[0066] Alternatively, the adjustable resistor 90 may be a plurality of resistors connected in parallel, each resistor being connected in series with a switch, and the resistance value of the adjustable resistor 90 is controlled by controlling the opening and closing of the switch. The number of parallel resistors of the adjustable resistor 90 can be selected as required, for example Figure 12 The adjustable resistor 90 includes three parallel resistors: a resistor R55, a resistor R74, and a resistor R77. The resistor R77 is connected in series with the switch SW1, the resistor R74 is connected in series with the switch SW2, and the resistor R55 is connected in series with the switch SW3. The resistance value of the adjustable resistor 90 is controlled by controlling the opening and closing of the switches SW1, SW2, and SW3.

[0067] refer to Figure 13 In some embodiments, the multi-parallel LED light string safety control system further includes a feedback circuit connected to the processor 50 for providing fault information. This fault information is detected by the processor 50 through various detection circuits and includes fault information such as LED open circuit faults, LED short circuit faults, power supply VIN overvoltage faults, and power supply VIN undervoltage faults. Different faults are fed back using different fault information to alert personnel to the specific fault information. Alternatively, the feedback circuit may be a display screen, indicator light, or speaker. This embodiment provides feedback to personnel, enabling them to promptly identify any faults in the multi-parallel LED light strings.

[0068] refer to Figure 14 and Figure 15 In some embodiments of a multi-parallel LED light string safety control system, the LED driver circuit 10 includes a constant current chip IC10 and its peripheral circuitry. Optionally, the constant current chip IC10 is an OC6701, though other constant current chips with similar functionality may also be used. The constant current chip IC10 includes a VDD pin, an EN pin, a TOFF pin, a GND pin, a SW pin, a FB pin, a CS pin, and a COMP pin. Its peripheral circuitry is shown in the figure, where A1 represents the first terminal of the LED driver circuit 10, and A2 represents the second terminal of the LED driver circuit 10.

[0069] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0070] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0071] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, software modules executed by a processor (50), or a combination of the two. The software modules may be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0072] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. All equivalent variations and modifications within the scope of the claims of the present invention are intended to be covered by the claims of the present invention.

Claims

1. A multi-parallel LED light string safety control system, characterized in that: The invention comprises an LED driving circuit (10), at least two groups of LED light strings (20), at least two first voltage detection circuits (30), a voltage dividing circuit (40) and a processor (50), wherein each of the LED light strings (20) corresponds to one of the first voltage detection circuits (30), and the LED light strings (20) comprise at least two LED lamp beads connected in series; The LED driving circuit (10) is used to convert the power supply VIN to drive the LED light string (20), and the input end of the LED driving circuit (10) is connected to the power supply VIN; the first end of the LED driving circuit (10) is connected to the first end of each group of the LED light strings (20), the second end of each group of the LED light strings (20) is connected to the first end of the corresponding first voltage detection circuit (30), the second end of each first voltage detection circuit (30) is connected to the second end of the LED driving circuit (10), and the third end of each first voltage detection circuit (30) is connected to the processor (50); the second end of the LED driving circuit (10) is connected to the first ground point through the voltage divider circuit (40); the processor (50) is connected to the LED driving circuit (10); and the voltage divider circuit (40) is connected to the processor (50); The processor (50) obtains the voltage across the voltage divider circuit (40); the processor (50) obtains the first detection voltage of each first voltage detection circuit (30); if a first detection voltage is the voltage across the voltage divider circuit (40), it indicates that an open circuit fault occurs in the LED light string (20) corresponding to the first voltage detection circuit (30); the processor (50) controls the LED drive circuit (10) to reduce the output current; When driving multiple parallel LED light strings, the LED driving circuit drives the multiple parallel LED light strings as a whole, and does not control the operating current of a single LED light string individually.

2. The multi-parallel LED light string safety control system according to claim 1, characterized in that: The first voltage detection circuit (30) comprises a first resistor R1 and a second resistor R2; The first end of the first resistor R1 is connected to the first end of the second resistor R2, the connection point between the first resistor R1 and the second resistor R2 is the first end of the first voltage detection circuit (30), the second end of the first resistor R1 is the second end of the first voltage detection circuit (30), and the second end of the second resistor R2 is the third end of the first voltage detection circuit (30).

3. The multi-parallel LED light string safety control system according to claim 2, characterized in that: The first voltage detection circuit (30) further includes a first capacitor C1, and the second end of the second resistor R2 is connected to a first grounding point via the first capacitor C1.

4. The multi-parallel LED light string safety control system according to claim 1, characterized in that: The voltage divider circuit (40) comprises a third resistor R3 and a fourth resistor R4, wherein the third resistor R3 and the fourth resistor R4 are connected in parallel, wherein the first end of the parallel connection is connected to the second end of the LED drive circuit (10), and the second end of the parallel connection is connected to the first ground point.

5. The multi-parallel LED light string safety control system according to claim 4, characterized in that: The voltage divider circuit (40) further includes a diode D1, wherein the anode of the diode D1 is connected to the second end of the LED drive circuit (10), and the cathode of the diode D1 is connected to the first grounding point.

6. The multi-parallel LED light string safety control system according to claim 1, characterized in that: It also includes a second voltage detection circuit (60), wherein a first end of the second voltage detection circuit (60) is connected to a first end of each of the LED light strings (20), and a second end of the second voltage detection circuit (60) is connected to the processor (50); The processor (50) obtains a second detection voltage of the second voltage detection circuit (60); if the second detection voltage is not within a preset voltage range, it indicates that a short circuit fault occurs in the LED light string (20); and the processor (50) controls the LED driving circuit (10) to stop driving the LED light string (20).

7. The multi-parallel LED light string safety control system according to claim 6, characterized in that: The second voltage detection circuit (60) comprises a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7; The first end of the fifth resistor R5 is the first end of the second voltage detection circuit (60), the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6 and the first end of the seventh resistor R7 respectively, the second end of the sixth resistor R6 is connected to the first grounding point, and the second end of the seventh resistor R7 is the second end of the second voltage detection circuit (60).

8. The multi-parallel LED light string safety control system according to claim 7, characterized in that: The device further includes a second capacitor C2 , wherein two ends of the second capacitor C2 are respectively connected to the second end of the sixth resistor R6 and the second end of the seventh resistor R7 .

9. The multi-parallel LED light string safety control system according to claim 1, characterized in that: It also includes a third voltage detection circuit (70), a first end of the third voltage detection circuit (70) is connected to the power supply VIN, a second end of the third voltage detection circuit (70) is connected to the processor (50), and a third end of the third voltage detection circuit (70) is connected to the first ground point; The processor (50) obtains a third detection voltage of the third voltage detection circuit (70); if the third detection voltage is greater than a first preset voltage, an overvoltage fault occurs in the power supply VIN, and the processor (50) executes an overvoltage protection strategy; If the third detection voltage is less than the second preset voltage, an undervoltage fault occurs in the power supply VIN, and the processor (50) executes an undervoltage protection strategy; wherein the first preset voltage is greater than the second preset voltage.

10. The multi-parallel LED light string safety control system according to claim 9, characterized in that: The third voltage detection circuit (70) comprises an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10; The first end of the eighth resistor R8 is the first end of the third voltage detection circuit (70), the second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9 and the first end of the tenth resistor R10 respectively, the second end of the ninth resistor R9 is the second end of the third voltage detection circuit (70), and the second end of the tenth resistor R10 is the third end of the third voltage detection circuit (70).

11. The multi-parallel LED light string safety control system according to claim 10, characterized in that: The third voltage detection circuit (70) further includes a third capacitor C3, wherein both ends of the capacitor C3 are respectively connected to the second end of the ninth resistor R9 and the second end of the tenth resistor R10.

12. The multi-parallel LED light string safety control system according to claim 1, characterized in that: It also includes a switch circuit (80), wherein a first end of the switch circuit (80) is connected to the processor (50), a second end of the switch circuit (80) is connected to a first ground point, and a third end of the switch circuit (80) is connected to a second ground point; When the processor (50) controls the switch circuit (80) to be turned on, the first grounding point and the second grounding point are connected; when the processor (50) controls the switch circuit (80) to be turned off, the first grounding point and the second grounding point are disconnected.

13. The multi-parallel LED light string safety control system according to claim 12, characterized in that: The switch circuit (80) comprises a MOS tube Q1, an eleventh resistor R11, a twelfth resistor R12 and a thirteenth resistor R13; The gate of the MOS tube Q1 is connected to the processor (50) via the eleventh resistor R11, the gate of the MOS tube Q1 is connected to the source of the MOS tube Q1 via the twelfth resistor R12, the source of the MOS tube Q1 is connected to the second grounding point via the thirteenth resistor R13; and the drain of the MOS tube Q1 is connected to the first grounding point.

14. The multi-parallel LED light string safety control system according to claim 1, characterized in that: It also includes a fourteenth resistor R14 and a fourth capacitor C4. The LED driving circuit (10) includes a driving chip U1; The first end of the fourteenth resistor R14 is connected to the feedback input pin FB of the driver chip U1, the second end of the fourteenth resistor R14 is connected to the processor (50), and the second end of the fourteenth resistor R14 is connected to the first ground point via the fourth capacitor C4.

15. The multi-parallel LED light string safety control system according to claim 1, characterized in that: The LED driving circuit (10) comprises a driving chip U1 and an adjustable resistor (90); a current sampling pin CS of the driving chip U1 is connected to a first ground point via the adjustable resistor (90); and the output current value of the LED driving circuit (10) is adjusted by adjusting the resistance value of the adjustable resistor (90).

16. The multi-parallel LED light string safety control system according to claim 1, characterized in that: It also includes a feedback circuit connected to the processor (50) and used to feed back fault information.

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