LED driver restart protection system and method

Abstract

The present invention provides an LED driver restart protection system and method. The system comprises at least a restart protection module, a driver module, a detection module, a compensation module, a charge-discharge module, an energy storage capacitor, and an LED load. When the bus voltage is powered down and an overflow signal from the compensation module is received, the restart protection module resets the compensation module and shuts off the current of the energy storage capacitor and the LED load, thereby preventing LED flicker and the power tube from burning out during restart of the LED driver circuit. When the bus voltage is powered up again, the restart protection module unlocks the compensation module to activate the charge-discharge module, keeps the LED load off, and restarts the driver module after the bus voltage stabilizes, thereby improving detection efficiency and stability.

Description

Technical Field

[0001] The present invention relates to the field of system design, and in particular to an LED drive restart protection system and method. Background Art

[0002] LED is a semiconductor electronic component that can emit light. In the early days, this electronic component could only emit low-brightness red light. With the development of technology and the advancement of manufacturing processes, LED has demonstrated performance advantages that traditional light sources cannot achieve, such as high efficiency, long service life, resistance to breakage, high switching brightness, and strong reliability. Therefore, LED has been widely used in lighting, display, projection and other fields.

[0003] Generally speaking, the overall efficiency of a single-stage linear LED driver is determined by the LED conduction voltage and the drive voltage. Among them, V LED is the LED conduction voltage, V IN When the LED driver circuit is restarted, the excessive charging current may cause the power tube inside the chip to burn out. At the same time, the flickering of the LED during restart will seriously reduce the overall efficiency and make it impossible to effectively identify the power-on and power-off status of the circuit.

[0004] Therefore, how to prevent the LED driver circuit from burning out the power tube, strobing, and failing to effectively identify the power-on and power-off status of the circuit when restarting has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide an LED driver restart protection system to solve the problems in the prior art that the LED driver circuit is prone to power tube burnout, flickering, and inability to effectively identify the power-on and power-off status of the circuit when restarting.

[0006] To achieve the above-mentioned and other related objectives, the present invention provides an LED driver restart protection system, which includes at least: a restart protection module, a driver module, a detection module, a compensation module, a charge and discharge module, an energy storage capacitor, and an LED load, wherein:

[0007] The positive electrode of the LED load is connected to the bus voltage;

[0008] The driving module is connected to the negative electrode of the LED load and is used to drive the LED load with a constant current;

[0009] The upper plate of the energy storage capacitor is connected to the bus voltage, and the lower plate is connected to the charge and discharge module;

[0010] The detection module is connected to the driving module and is used to detect the cathode voltage of the LED load;

[0011] The compensation module is connected to the output end of the detection module and generates corresponding compensation current and compensation voltage based on the output signal of the detection module; when the bus voltage is disconnected, the compensation module generates an overflow signal;

[0012] The charging and discharging module is connected to the lower plate of the energy storage capacitor and the output end of the compensation module, and adjusts the charging and discharging current of the energy storage capacitor based on the compensation current;

[0013] The restart protection module is connected to the compensation module, the charge-discharge module, and the drive module. When the bus voltage is powered off and the overflow signal is received, the restart protection module resets the compensation module and limits the voltage of the charge-discharge module, thereby cutting off the current of the energy storage capacitor, and limits the voltage of the drive module, thereby cutting off the current of the LED load. When the bus voltage is powered on again, the restart protection module unlocks the compensation module to start the charge-discharge module, thereby starting the energy storage capacitor and keeping the LED load in the off state. After the bus voltage stabilizes, the restart protection module starts the drive module, thereby starting the LED load.

[0014] Optionally, the LED drive restart protection system further includes a rectifier module, which rectifies the alternating current to obtain the bus voltage.

[0015] Optionally, the charge and discharge module includes: a first operational amplifier, a first power tube, a first resistor, a second resistor and a third resistor, wherein: one end of the first resistor is connected to the bus voltage, and the other end is connected to the source of the first power tube via the second resistor; the non-inverting input end of the first operational amplifier receives the compensation current, and the inverting input end is connected to the connection node of the first resistor and the second resistor; the gate of the first power tube is connected to the output of the first operational amplifier, the drain is connected to the lower plate of the energy storage capacitor, and the source is grounded via the third resistor.

[0016] Optionally, the LED driving restart protection system further includes the power regulating module, which is connected between the bus voltage and the charging and discharging module and is used to adjust the power factor of the LED driving restart protection system.

[0017] Optionally, the driving module includes: a second operational amplifier, a second power tube and a fourth resistor, wherein the drain of the second power tube is connected to the negative electrode of the LED load, and the source is grounded via the fourth resistor; the inverting input of the second operational amplifier is connected to the source of the second power tube, the non-inverting input receives a first reference signal, and the output end is connected to the gate of the second power tube.

[0018] Optionally, the restart protection module includes: a preparation unit, a voltage flip unit, a reset unit, a first AND gate, a second AND gate, a third AND gate, a first trigger, a second trigger, a first pull-down unit, a second pull-down unit and a NOT gate, wherein,

[0019] The voltage flipping unit receives the bus voltage and outputs a corresponding flipping control signal based on the power-up and power-down status of the bus voltage; the NOT gate is connected to the output terminal of the voltage flipping unit; the first AND gate receives the NOT gate output signal and the overflow signal; the input terminal of the first flip-flop is grounded, and the clock terminal is connected to the output terminal of the first AND gate; the input terminal of the second flip-flop is connected to the power supply voltage, the reset terminal is connected to the output terminal of the first flip-flop, and the clock terminal is connected to the output terminal of the voltage flip-flop;

[0020] The preparation unit is connected to the output terminal of the second trigger and receives the compensation voltage, and generates a first preparation signal and a second preparation signal based on the output of the second trigger and the compensation voltage, and the first preparation signal and the second preparation signal are valid when the bus voltage is powered on;

[0021] The input of the reset unit is connected to the output end of the preparation unit, and the output end is connected to the reset end of the first flip-flop, and the first flip-flop is reset when the first preparation signal and the second preparation signal are valid;

[0022] The input end of the second AND gate is connected to the output end of the preparation unit and the output end of the first trigger, and when the bus voltage is powered off, the compensation module is reset, and when the bus voltage is powered on, the compensation module is unlocked;

[0023] The first pull-down unit is connected to the output end of the first trigger, and when the bus voltage is powered off, limits the voltage of the charge-discharge module, thereby shutting off the current of the energy storage capacitor; when the bus voltage is powered on again, starts the charge-discharge module, thereby starting the energy storage capacitor;

[0024] The input end of the third AND gate is connected to the output end of the preparation unit and the output end of the first trigger, and the output end is connected to the second pull-down unit. When the bus voltage is powered off, the voltage of the driving module is limited, thereby cutting off the current of the LED load; when the bus voltage is powered on again, the LED load is kept in the off state, and the driving module is started after the bus voltage stabilizes, thereby starting the LED load.

[0025] Optionally, the preparation unit includes: a detection component, a third operational amplifier, a first OR gate, a fifth resistor and a third trigger, wherein the detection component is connected to the power supply voltage and outputs the second preparation signal; the non-inverting input of the third operational amplifier receives the compensation voltage, the inverting input is connected to the first reference voltage, and the third operational amplifier is enabled based on the second preparation signal; the input end of the first OR gate is connected to the output end of the second trigger and the output end of the detection component; the input end of the third trigger is connected to the power supply voltage via the fifth resistor, the clock end is connected to the output of the third operational amplifier, the reset end is connected to the output of the first OR gate, and the first preparation signal is output.

[0026] Optionally, the voltage flipping unit includes: a comparator, a Schmitt trigger, a delay component and a switching switch, wherein the non-inverting input of the comparator receives the sampling signal of the bus voltage, and the inverting input is connected to the second reference voltage or the third reference voltage through the switching switch; the input of the Schmitt trigger is connected to the output of the comparator, and the output is connected to the control end of the switching switch, and the second reference voltage or the third reference voltage is switched based on the sampling signal of the bus voltage; the input of the delay component is connected to the output of the Schmitt trigger; and the input of the delay component is connected to the output of the comparator.

[0027] Optionally, the reset unit includes: a second OR gate, a fourth AND gate and an inverting delay component, wherein the first input end of the fourth AND gate receives the second ready signal, and the second input end receives the output signal of the first ready signal processed by the inverting delay component; the first input end of the second OR gate is connected to the output end of the fourth AND gate, the second input end receives the first ready signal, and the output end outputs the reset signal.

[0028] The present invention provides an LED driver restart protection method, which is implemented based on the LED driver restart protection system, and is characterized in that the LED driver restart protection method at least includes:

[0029] When the bus voltage is powered off and the compensation module outputs an overflow signal, the compensation module is reset, and the voltage of the charge and discharge module is limited, thereby cutting off the current of the energy storage capacitor, limiting the voltage of the drive module, thereby cutting off the current of the LED load;

[0030] When the bus voltage is powered on again, the reset of the compensation module is released, the charge and discharge module is started, and then the energy storage capacitor is started, and the LED load is kept in the off state. After the bus voltage stabilizes, the drive module is started, and then the LED load is started.

[0031] As described above, the LED driver restart protection system and method of the present invention have the following beneficial effects:

[0032] 1. During the process of identifying power failure and powering on again, the compensation module is reset and the current of the energy storage capacitor and LED load is turned off to avoid LED flickering and prevent the power tube from burning when the system restarts.

[0033] 2. During the restart protection process, there is no need to detect the driver module and thus the status of the LED load, which improves applicability.

[0034] 3. It can effectively identify the power-on and power-off status, improving detection efficiency and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Shown is a structural schematic diagram of an exemplary LED restart protection circuit of the present application.

[0036] Figure 2 Shown is a structural schematic diagram of the LED driver restart protection system provided in an embodiment of the present application.

[0037] Figure 3 Shown is a schematic structural diagram of the charge and discharge module provided in an embodiment of the present application.

[0038] Figure 4 Shown is a schematic structural diagram of a driving module provided in an embodiment of the present application.

[0039] Figure 5 Shown is a structural diagram of the restart protection module provided in an embodiment of the present application.

[0040] Figure 6 Shown is a structural schematic diagram of a preparation unit provided in an embodiment of the present application.

[0041] Figure 7 Shown is a structural schematic diagram of a voltage flip unit provided in an embodiment of the present application.

[0042] Figure 8 Shown is a structural schematic diagram of a reset unit provided in an embodiment of the present application.

[0043] Component number description

[0044] 100 rectifier modules

[0045] 200 driver module

[0046] 300 LED load

[0047] 400 Detection Module

[0048] 500 compensation module

[0049] 600 Power Conditioning Module

[0050] 700 charging and discharging module

[0051] 800 Restart protection module

[0052] 801 Voltage Inversion Unit

[0053] 802 NOT Gate

[0054] 803 First AND Gate

[0055] 804 First Trigger

[0056] 805 Second Trigger

[0057] 806 Preparation Unit

[0058] 807 Reset Unit

[0059] 808 Second AND Gate

[0060] 809 First pull-down unit

[0061] 810 Third AND Gate

[0062] 811 Second pull-down unit

[0063] 821 Comparator

[0064] 822 Schmitt trigger

[0065] 823 Delay Component

[0066] 824 Toggle Switch

[0067] 861 Detection Components

[0068] 862 First OR Gate

[0069] 863 Third Trigger

[0070] 871 Fourth AND Gate

[0071] 872 Inverting Delay Component

[0072] 873 Second OR Gate

[0073] 900 Energy Storage Capacitor

[0074] OP1 first operational amplifier

[0075] OP2 Second operational amplifier

[0076] OP3 third operational amplifier

[0077] R1 first resistor

[0078] R2 Second resistor

[0079] R3 third resistor

[0080] R4 fourth resistor

[0081] R5 fifth resistor

[0082] Q1 first power tube

[0083] Q2 second power tube DETAILED DESCRIPTION

[0084] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0085] See also Figures 1 to 8 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0086] Figure 1 This paper demonstrates an LED restart protection circuit. When power is turned off, the voltage at the comparator's inverting input falls below the reference voltage Vref, causing the comparator to output "1" and reset the D-type flip-flop. When the compensation module outputs "1," the D-type flip-flop's output also reaches "1," which in turn resets the compensation module. This limits the gate voltage of the power transistors in the charge / discharge module, thereby limiting the charging current. When power is turned back on, the voltage at the comparator's inverting input rises above the reference voltage Vref, causing the comparator to output "0," reset the D-type flip-flop, and reset the AND gate to output "0." This resets the compensation module, allowing the circuit to resume normal operation.

[0087] from Figure 1 It can be seen that the inverting input of the comparator is connected to the driver module, and the driver module controls the current of the LED load. When the power is restored, the voltage at the inverting input of the comparator keeps changing, causing the current of the LED load to change frequently, thus causing the LED to flicker.

[0088] Therefore, the present invention proposes an LED driver restart protection system and method, which are as follows:

[0089] like Figure 2 As shown, this embodiment provides an LED driver restart protection system, which includes at least: a restart protection module 800, a driver module 200, a detection module 400, a compensation module 500, a charge and discharge module 700, an energy storage capacitor 900 and an LED load 300, wherein:

[0090] like Figure 2 As shown, the positive electrode of the LED load 300 is connected to the bus voltage.

[0091] Specifically, if Figure 2 As shown, the LED driving restart protection system further includes a rectifier module 100, and the rectifier module 100 rectifies the alternating current to obtain the bus voltage.

[0092] like Figure 2 As shown, the driving module 200 is connected to the negative electrode of the LED load 300 for driving the LED load 300 with a constant current.

[0093] Specifically, as an example, Figure 4 As shown, the driver module 200 includes: a second operational amplifier OP2, a second power transistor Q2, and a fourth resistor R4. The drain of the second power transistor Q2 is connected to the cathode of the LED load 300, and the source is grounded via the fourth resistor R4. The inverting input of the second operational amplifier OP2 is connected to the source of the second power transistor Q2, the non-inverting input receives a first reference signal Vref1, and the output is connected to the gate of the second power transistor Q2. It should be noted that the driver module 200 can also be implemented using an application-specific integrated circuit architecture. Any solution capable of providing constant current driving for the LED load 300 is applicable, and is not limited to this embodiment.

[0094] like Figure 2 As shown, the upper plate of the energy storage capacitor 900 is connected to the bus voltage, and the lower plate is connected to the charge and discharge module 700. It should be noted that any device capable of storing energy is applicable, and this embodiment is not limited thereto.

[0095] like Figure 2 As shown, the detection module 400 is connected to the driving module 200 and is used to detect the cathode voltage of the LED load 300. It should be noted that the detection module 400 includes but is not limited to a sensor, and any device capable of voltage detection is applicable, not limited to this embodiment.

[0096] like Figure 2As shown, the compensation module 500 is connected to the output terminal of the detection module 400 and generates corresponding compensation current and compensation voltage based on the output signal of the detection module 400. When the bus voltage is disconnected, the compensation module 500 generates an overflow signal. It should be noted that the compensation module 500 includes but is not limited to an IP core (Intellectual Property core, a pre-designed circuit function module used in an application-specific integrated circuit or field-programmable gate array). Any device that can implement the compensation function is applicable, and is not limited to this embodiment.

[0097] like Figure 2 As shown, the charge and discharge module 700 is connected to the lower plate of the energy storage capacitor 900 and the output end of the compensation module 500, and adjusts the charge and discharge current of the energy storage capacitor 900 based on the compensation current.

[0098] Specifically, as an example, Figure 3 As shown, the charge and discharge module 700 includes: a first operational amplifier OP1, a first power transistor Q1, a first resistor R1, a second resistor R2, and a third resistor R3, wherein: one end of the first resistor R1 is connected to the bus voltage, and the other end is connected to the source of the first power transistor Q1 via the second resistor R2; the non-inverting input of the first operational amplifier OP1 receives the compensation current, and the inverting input is connected to the connection node of the first resistor R1 and the second resistor R2; the gate of the first power transistor Q1 is connected to the output of the first operational amplifier OP1, the drain is connected to the lower plate of the energy storage capacitor 900, and the source is grounded via the third resistor R3. It should be noted that the charge and discharge module can also use an IP core (Intellectual Property core, a pre-designed circuit function module used in a dedicated integrated circuit or field programmable logic gate array), and any solution that can adjust the charge and discharge current of the energy storage capacitor 900 is applicable, and is not limited to this embodiment.

[0099] More specifically, as an example, Figure 2 As shown, the LED driver restart protection system further includes the power regulation module 600, which is connected between the bus voltage and the charge-discharge module 700 and is used to adjust the power factor of the LED driver restart protection system. It should be noted that the LED driver restart protection system can also be implemented using a digital signal processor or microprocessor. Any device capable of power factor adjustment is applicable, and the present embodiment is not limited thereto.

[0100] like Figure 2As shown, the restart protection module 800 is connected to the compensation module 500, the charge and discharge module 700 and the drive module 200. When the bus voltage is powered off and the overflow signal is received, the restart protection module 800 resets the compensation module 500 and limits the voltage of the charge and discharge module 700, thereby turning off the current of the energy storage capacitor 900, limiting the voltage of the drive module 200, and thereby turning off the current of the LED load 300; when the bus voltage is powered on again, the restart protection module 800 unlocks the compensation module 500 to start the charge and discharge module 700, thereby starting the energy storage capacitor 900, and keeping the LED load 300 in the off state. After the bus voltage stabilizes, the drive module 200 is started, and thereby the LED load 300 is started.

[0101] Specifically, as an example, Figure 5 As shown, the restart protection module 800 includes: a preparation unit 806, a voltage flip unit 801, a reset unit 807, a first AND gate 803, a second AND gate 808, a third AND gate 810, a first trigger 804, a second trigger 805, a first pull-down unit 809, a second pull-down unit 811 and a NOT gate 802, wherein,

[0102] Specifically, as an example, Figure 5 As shown, the voltage flip unit 801 receives the bus voltage and outputs a corresponding flip control signal based on the power-up and power-down states of the bus voltage; the NOT gate 802 is connected to the output end of the voltage flip unit 801; the first AND gate 803 receives the output signal of the NOT gate 802 and the overflow signal; the input end of the first trigger 804 is grounded, and the clock end Y is connected to the output end of the first AND gate 803; the input end of the second trigger 805 is connected to the power supply voltage Vdd, the reset end is connected to the output end CH1_outQ of the first trigger 804, and the clock end X is connected to the output end of the voltage flip unit 801.

[0103] More specifically, as an example, Figure 7As shown, the voltage flipping unit 801 includes: a comparator 821, a Schmitt trigger 822, a delay component 823 and a switching switch 824, wherein the non-inverting input terminal of the comparator 821 receives the sampling signal of the bus voltage, and the inverting input terminal is connected to the second reference voltage Vref2 or the third reference voltage Vref3 through the switching switch 824; the input terminal of the Schmitt trigger 822 is connected to the output terminal of the comparator 821, and the output terminal is connected to the control terminal of the switching switch 824, and the second reference voltage Vref2 or the third reference voltage Vref3 is switched based on the sampling signal of the bus voltage; the input terminal of the delay component 823 is connected to the output terminal of the Schmitt trigger 822; the input terminal of the delay component 823 is connected to the output terminal of the comparator 821. It should be noted that, as an example, the voltage value of the second reference voltage Vref2 is greater than the voltage value of the third reference voltage Vref3. In the power-on state, the sampling signal of the bus voltage is higher than the second reference voltage Vref2, and in the power-off state, the sampling signal of the bus voltage is lower than the second reference voltage Vref3. The Schmitt trigger 822 switches and outputs a corresponding flip control signal through the delay component 823. It should be noted that any solution capable of voltage flipping is applicable, and this embodiment is not limited thereto.

[0104] Specifically, as an example, Figure 5 As shown, the preparation unit 806 is connected to the output terminal CH2_outQ of the second trigger 805 and receives the compensation voltage, and generates a first preparation signal and a second preparation signal based on the output of the second trigger 805 and the compensation voltage. When the bus voltage is powered on, the first preparation signal and the second preparation signal are valid.

[0105] More specifically, as an example, Figure 6 As shown, the preparation unit 806 includes: a detection component 861, a third operational amplifier OP3, a first OR gate 862, a fifth resistor R5 and a third trigger 863, wherein the detection component 861 is connected to the power supply voltage Vdd and outputs the second preparation signal; the non-inverting input of the third operational amplifier OP3 receives the compensation voltage, the inverting input is connected to the first reference voltage Vref1, and the third operational amplifier OP3 is enabled based on the second preparation signal; the input end of the first OR gate 862 is connected to the Figure 5 The output terminal CH2_outQ of the second trigger 805 and the output terminal of the detection component 861 are shown; the input terminal of the third trigger 863 is connected to the power supply voltage Vdd through the fifth resistor R5, the clock terminal is connected to the output of the third operational amplifier OP3, and the reset terminal is connected to the output of the first OR gate 862, outputting the first ready signal.

[0106] Specifically, as an example, Figure 5 As shown, the input of the reset unit 807 is connected to the output end of the preparation unit 806, and the output end is connected to the reset end of the first trigger 804. When the first preparation signal and the second preparation signal are valid, the first trigger 804 is reset.

[0107] More specifically, as an example, Figure 8 As shown, the reset unit 807 includes: a second OR gate 873, a fourth AND gate 871, and an inverting delay component 872, wherein the first input terminal of the fourth AND gate 871 receives the second ready signal, and the second input terminal receives the output signal of the first ready signal through the inverting delay component 872; the first input terminal of the second OR gate 873 is connected to the output terminal of the fourth AND gate, the second input terminal receives the first ready signal, and the output terminal outputs the reset signal. It should be noted that the reset unit 807 utilizes the characteristics of competition and hazard in digital circuits, and uses the inverting delay component 872 to extend the time difference between the first ready signal and the second ready signal, that is, to amplify the competition effect, so that the reset signal is transmitted to the Figure 5 The reset terminal of the first flip-flop 804 is shown.

[0108] Specifically, as an example, Figure 5 As shown, the input end of the second AND gate 808 is connected to the output end of the preparation unit 806 and the output end CH1_outQ of the first trigger 804. When the bus voltage is powered off, the compensation module 500 is reset, and when the bus voltage is powered on, the compensation module 500 is unlocked.

[0109] Specifically, as an example, Figure 5 As shown, the first pull-down unit 809 is connected to the output terminal CH1_outQ of the first trigger 804. When the bus voltage is powered off, the voltage of the charge and discharge module 700 is limited, thereby shutting down the first trigger 804. Figure 2 When the bus voltage is powered on again, the charging and discharging module 700 is started, and then the charging and discharging module 700 is started. Figure 2 Energy storage capacitor 900 is shown.

[0110] Specifically, as an example, Figure 5 As shown, the input end of the third AND gate 810 is connected to the output end of the preparation unit 806 and the output end CH1_outQ of the first trigger 804, and the output end is connected to the second pull-down unit 811. When the bus voltage is powered off, the voltage of the driving module 200 is limited, thereby shutting down. Figure 2When the bus voltage is powered on again, the current of the LED load 300 is Figure 2 The LED load 300 shown in FIG remains in the off state, and the driver module 200 is started after the bus voltage stabilizes, and then the LED load 300 is started. Figure 2 The LED load 300 is shown in FIG.

[0111] More specifically, as an example, Figure 5 As shown, when the bus voltage is powered off, the flip control signal output by the voltage flip unit 801 is "0", and at the same time the compensation module 500 outputs an overflow signal, so that the first trigger 804 is triggered and outputs "0", the second AND gate 808 outputs "0", and then the compensation module 500 is reset, the first pull-down unit 809 cuts off the current of the energy storage capacitor 900 through the charge and discharge module 700, and the second pull-down unit 811 cuts off the current of the LED load 300 through the drive module 200.

[0112] like Figure 5 As shown, when the bus voltage is powered on again, the flip control signal output by the voltage flip unit 801 is "1", so that the second trigger 805 is triggered and outputs "1", making the first ready signal "1", making the reset signal output by the reset unit 807 "1", making the first trigger 804 triggered and outputting "1", releasing the reset of the compensation module 500 to start the charge and discharge module 700, and keeping the LED load 300 turned off, and then starting the drive module 200 after the bus voltage stabilizes.

[0113] As an example, an LED driver restart protection method is implemented based on the LED driver restart protection system, and the LED driver restart protection method at least includes:

[0114] like Figure 2 As shown, when the bus voltage is powered off and the compensation module 500 outputs an overflow signal, the compensation module 500 is reset, and the voltage of the charge and discharge module 700 is limited, thereby shutting off the current of the energy storage capacitor 900, limiting the voltage of the drive module 200, and thereby shutting off the current of the LED load 300.

[0115] like Figure 2 As shown, when the bus voltage is powered on again, the reset of the compensation module 500 is released, the charge and discharge module 700 is started, and then the energy storage capacitor 900 is started, and the LED load 300 is kept in the off state. After the bus voltage stabilizes, the driving module 200 is started, and then the LED load 300 is started.

[0116] More specifically, as an example, the LED driver restart protection method can be implemented using an IP core (Intellectual Property core, a pre-designed circuit function module used in a dedicated integrated circuit or a field programmable logic gate array). Any solution that can perform the LED driver restart protection method is applicable, not limited to this embodiment.

[0117] In summary, the LED driver restart protection system and method of the present invention at least includes: a restart protection module, a driving module, a detection module, a compensation module, a charge and discharge module, an energy storage capacitor and an LED load, wherein: the positive electrode of the LED load is connected to the bus voltage; the driving module is connected to the negative electrode of the LED load, and is used to drive the LED load with a constant current; the upper plate of the energy storage capacitor is connected to the bus voltage, and the lower plate is connected to the charge and discharge module; the detection module is connected to the driving module, and is used to detect the negative electrode voltage of the LED load; the compensation module is connected to the output end of the detection module, and generates a corresponding compensation voltage based on the output signal of the detection module. current and compensation voltage; the charging and discharging module is connected to the lower plate of the energy storage capacitor and the output end of the compensation module, and adjusts the charging and discharging current of the energy storage capacitor based on the compensation current; the restart protection module is connected to the compensation module, the charging and discharging module and the driving module. When the bus voltage is powered off and an overflow signal of the compensation module is received, the restart protection module resets the compensation module and cuts off the current of the energy storage capacitor and the LED load; when the bus voltage is powered on again, the restart protection module unlocks the compensation module to start the charging and discharging module, keeps the LED load off, and waits until the bus voltage stabilizes before starting the driving module.

[0118] The LED driver restart protection system and method of the present invention can disconnect the energy storage capacitor and LED load during the process from identifying a power failure to powering back on, thereby preventing LED flicker and preventing the LED driver circuit from burning out the power transistor during restart. Furthermore, during the restart protection process, there is no need to check the driver module and, consequently, the LED load status, thereby improving applicability. Finally, the system can effectively identify power-on and power-off states, improving detection efficiency and stability.

[0119] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An LED driver restart protection system, characterized in that: The LED driver restart protection system at least includes: a restart protection module, a driver module, a detection module, a compensation module, a charge and discharge module, an energy storage capacitor and an LED load, wherein: the positive electrode of the LED load is connected to the bus voltage; The driving module is connected to the negative electrode of the LED load and is used to drive the LED load with a constant current; The upper plate of the energy storage capacitor is connected to the bus voltage, and the lower plate is connected to the charge and discharge module; The detection module is connected to the driving module and is used to detect the cathode voltage of the LED load; The compensation module is connected to the output end of the detection module and generates corresponding compensation current and compensation voltage based on the output signal of the detection module; when the bus voltage is disconnected, the compensation module generates an overflow signal; The charging and discharging module is connected to the lower plate of the energy storage capacitor and the output end of the compensation module, and adjusts the charging and discharging current of the energy storage capacitor based on the compensation current; The restart protection module is connected to the compensation module, the charge-discharge module, and the driver module. When the bus voltage is powered down and the overflow signal is received, the voltage flipping unit in the restart protection module outputs a flipping control signal of "0" to trigger the first trigger in the restart protection module and output "0". The second AND gate in the restart protection module outputs "0", thereby resetting the compensation module, limiting the voltage of the charge-discharge module, and thus shutting off the current of the energy storage capacitor. The voltage of the driver module is also limited, thereby shutting off the current of the LED load. When the bus voltage is powered up again, the voltage flipping unit in the restart protection module outputs a flipping control signal of "1", triggering the first trigger in the restart protection module and outputting "1", thereby unlocking the compensation module to activate the charge-discharge module, thereby activating the energy storage capacitor and keeping the LED load in an off state. After the bus voltage stabilizes, the driver module is activated, thereby activating the LED load. The voltage flipping unit receives the bus voltage, the output of the second AND gate is connected to the compensation module, and the input of the second AND gate is connected to the output of the first trigger.

2. The LED driver restart protection system according to claim 1, characterized in that: The LED drive restart protection system further includes a rectifier module, which rectifies the alternating current to obtain the bus voltage.

3. The LED driver restart protection system according to claim 1, characterized in that: The charge and discharge module includes: a first operational amplifier, a first power tube, a first resistor, a second resistor and a third resistor, wherein: one end of the first resistor is connected to the bus voltage, and the other end is connected to the source of the first power tube via the second resistor; the non-inverting input end of the first operational amplifier receives the compensation current, and the inverting input end is connected to the connection node of the first resistor and the second resistor; the gate of the first power tube is connected to the output of the first operational amplifier, the drain is connected to the lower plate of the energy storage capacitor, and the source is grounded via the third resistor.

4. The LED driver restart protection system according to claim 1, characterized in that: The LED driving restart protection system further includes a power regulating module, which is connected between the bus voltage and the charging and discharging module and is used to regulate the power factor of the LED driving restart protection system.

5. The LED driver restart protection system according to claim 1, characterized in that: The driving module includes: a second operational amplifier, a second power tube and a fourth resistor, wherein the drain of the second power tube is connected to the negative electrode of the LED load, and the source is grounded via the fourth resistor; the inverting input of the second operational amplifier is connected to the source of the second power tube, the non-inverting input receives a first reference signal, and the output end is connected to the gate of the second power tube.

6. The LED driver restart protection system according to claim 1, characterized in that: The restart protection module further includes: a preparation unit, a reset unit, a first AND gate, a third AND gate, a second trigger, a first pull-down unit, a second pull-down unit and a NOT gate, wherein: The voltage flip unit outputs a corresponding flip control signal based on the power-up and power-down states of the bus voltage; the NOT gate is connected to the output end of the voltage flip unit; the first AND gate receives the NOT gate output signal and the overflow signal; the input end of the first flip-flop is grounded, and the clock end is connected to the output end of the first AND gate; the input end of the second flip-flop is connected to the supply voltage, the reset end is connected to the output end of the first flip-flop, and the clock end is connected to the output end of the voltage flip unit; The preparation unit is connected to the output terminal of the second trigger and receives the compensation voltage, and generates a first preparation signal and a second preparation signal based on the output of the second trigger and the compensation voltage, and the first preparation signal and the second preparation signal are valid when the bus voltage is powered on; The input end of the reset unit is connected to the output end of the preparation unit, and the output end is connected to the reset end of the first flip-flop, and the first flip-flop is reset when the first preparation signal and the second preparation signal are valid; The input end of the second AND gate is also connected to the output end of the preparation unit, and when the bus voltage is powered off, the compensation module is reset, and when the bus voltage is powered on, the compensation module is unlocked; The first pull-down unit is connected to the output end of the first trigger, and when the bus voltage is powered off, limits the voltage of the charge-discharge module, thereby shutting off the current of the energy storage capacitor; when the bus voltage is powered on again, starts the charge-discharge module, thereby starting the energy storage capacitor; The input end of the third AND gate is connected to the output end of the preparation unit and the output end of the first trigger, and the output end is connected to the second pull-down unit. When the bus voltage is powered off, the voltage of the driving module is limited, thereby cutting off the current of the LED load; when the bus voltage is powered on again, the LED load is kept in the off state, and the driving module is started after the bus voltage stabilizes, thereby starting the LED load.

7. The LED driver restart protection system according to claim 6, characterized in that: The preparation unit includes: a detection component, a third operational amplifier, a first OR gate, a fifth resistor and a third trigger, wherein the detection component is connected to the power supply voltage and outputs the second preparation signal; the non-inverting input of the third operational amplifier receives the compensation voltage, the inverting input is connected to the first reference voltage, and the third operational amplifier is enabled based on the second preparation signal; the input end of the first OR gate is connected to the output end of the second trigger and the output end of the detection component; the input end of the third trigger is connected to the power supply voltage via the fifth resistor, the clock end is connected to the output of the third operational amplifier, the reset end is connected to the output of the first OR gate, and the first preparation signal is output.

8. The LED driver restart protection system according to claim 6, characterized in that: The voltage flipping unit includes: a comparator, a Schmitt trigger, a delay component and a switching switch, wherein the non-inverting input terminal of the comparator receives the sampling signal of the bus voltage, and the inverting input terminal is connected to the second reference voltage or the third reference voltage through the switching switch; the input terminal of the Schmitt trigger is connected to the output terminal of the comparator, and the output terminal is connected to the control terminal of the switching switch, and the second reference voltage or the third reference voltage is switched based on the sampling signal of the bus voltage; the input terminal of the delay component is connected to the output terminal of the Schmitt trigger; and the input terminal of the delay component is connected to the output terminal of the comparator.

9. The LED driver restart protection system according to claim 6, characterized in that: The reset unit includes: a second OR gate, a fourth AND gate and an inverting delay component, wherein the first input end of the fourth AND gate receives the second ready signal, and the second input end receives the output signal of the first ready signal processed by the inverting delay component; the first input end of the second OR gate is connected to the output end of the fourth AND gate, the second input end receives the first ready signal, and the output end outputs a reset signal.

10. A LED driver restart protection method, implemented based on the LED driver restart protection system according to any one of claims 1 to 9, characterized in that: The LED driver restart protection method at least includes: When the bus voltage is powered off and the compensation module outputs an overflow signal, the compensation module is reset, and the voltage of the charge and discharge module is limited, thereby cutting off the current of the energy storage capacitor, limiting the voltage of the drive module, thereby cutting off the current of the LED load; When the bus voltage is powered on again, the reset of the compensation module is released, the charge and discharge module is started, and then the energy storage capacitor is started, and the LED load is kept in the off state. After the bus voltage stabilizes, the drive module is started, and then the LED load is started.

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