An input monitoring and protection system for LED drive power supply

Abstract

The present invention relates to the technical field of driving power supply, and provides an input monitoring protection system for LED driving power supply, comprising: a single chip microcomputer and an analog-to-digital conversion circuit embedded in the single chip microcomputer; wherein the single chip microcomputer comprises an analog input port and a PWM switch, the analog input port is electrically connected to the input end of the analog-to-digital conversion circuit, and the PWM switch is electrically connected to the output end of the analog-to-digital conversion circuit; the analog-to-digital converter is used to collect an input signal of the analog input port, determine a real-time voltage value of the input signal, and judge whether the real-time voltage value exceeds a preset input voltage range; wherein, when the real-time voltage value exceeds the preset input voltage range, the PWM switch is controlled by the single chip microcomputer to switch off the output PWM signal.

Description

Technical Field

[0001] The invention relates to the field of LED equipment, and in particular to an input monitoring and protection system for an LED driving power supply. Background Art

[0002] With the widespread application of LED devices, LED driver power supplies are constantly being updated. Traditional LED driver power supplies such as Figure 2 and Figure 3 As shown, it is composed of an input detection circuit, an MCU control unit and an LED output drive unit.

[0003] The input detection circuit receives AC input and DC input, and then converts the input voltage into a square wave form. Through the MCU control unit, the MCU control unit generates a PWM control signal for controlling the LED output drive unit based on the square wave and level signal.

[0004] AC input signal and DC input signal need to be detected and identified, such as Figure 2 As shown, as shown in patent document CN202311252554.6, a lighting fixture operation data detection circuit and an input voltage sampling circuit in a detection device, during the detection process of the input signal, it is triggered by the external interrupt of the rising and falling edges of the microcontroller to obtain the high and low levels of the input I / O port. If the external interrupt is continuously triggered, it is judged as AC input, and then the dimming process is entered. If the interrupt is not triggered for more than 200ms, the high and low levels of the current I / O port are directly obtained. The high level is judged as DC input, and the program operation enters the emergency mode. The low level is judged to enter the light-off mode.

[0005] However, the above method can only determine whether the input signal type is AC or DC, but cannot determine the input voltage range. If the input voltage exceeds the rated range, the power supply may be damaged. Summary of the invention

[0006] The present invention proposes an input monitoring protection system for an LED driving power supply, which is used to determine whether the input signal type is AC or DC, but cannot determine the input voltage range. If the input voltage exceeds the rated range, the power supply will be damaged.

[0007] In a first aspect, the present invention provides an input monitoring and protection system for an LED driving power supply, comprising a single-chip microcomputer and an analog-to-digital conversion circuit embedded in the single-chip microcomputer;

[0008] The single chip microcomputer includes an analog input port and a PWM switch, the analog input port is electrically connected to the input end of the analog-to-digital conversion circuit, and the PWM switch is electrically connected to the output end of the analog-to-digital conversion circuit;

[0009] The analog-to-digital converter is used to collect the input signal of the analog input port, determine the real-time voltage value of the input signal, and judge whether the real-time voltage value exceeds the preset input voltage range;

[0010] When the real-time voltage value exceeds the preset input voltage range, the PWM switch is controlled by the single-chip microcomputer to switch off the output PWM signal.

[0011] Furthermore, the single chip microcomputer is also connected to a negative feedback operational amplifier, and the input end of the analog input port is electrically connected to the output end of the negative feedback operational amplifier.

[0012] Further, when the input signal is an AC signal, the negative feedback operational amplifier converts the AC signal into a sine wave signal with an amplitude of 3.3V;

[0013] Among them, after the sinusoidal wave signal is collected by the analog-to-digital conversion circuit, the actual AC input voltage and frequency are determined based on the current maximum value, minimum value and time difference of the voltage, and the real-time voltage value is confirmed.

[0014] Furthermore, when the input signal is a DC signal, the negative feedback operational amplifier converts the DC signal into an analog signal with an amplitude of 0 to 3.3V;

[0015] Among them, after the analog signal is collected by the analog-to-digital conversion circuit, the real-time voltage value is determined based on the current voltage value, the reference voltage value and the gain of the negative feedback operational amplifier.

[0016] Furthermore, when the input signal is an input / output signal, the analog-to-digital conversion circuit controls the single-chip microcomputer to respond to the light control mode of the LED device based on the thresholds of input undervoltage and input overvoltage, and turns off the output PWM signal.

[0017] Furthermore, the lighting control modes include: dimming mode, light off mode and emergency mode.

[0018] Furthermore, the single chip microcomputer is also used for:

[0019] Generate a first warning signal and a second warning signal according to the voltage sampling signal of the analog input port, the first warning signal is used to indicate that the input voltage reaches a preset value, and the second warning signal indicates that the LED device is shut down normally;

[0020] The switch control signal is adjusted according to the first warning signal and the second warning signal, wherein:

[0021] According to the effective state of the first warning signal or the second warning signal, a constant current compensation interface is set.

[0022] Further, when the analog-to-digital converter receives an input signal, it determines whether it is an AC input signal or a DC input signal;

[0023] Determine a first shutdown range of the PWM shutdown device according to the AC input signal;

[0024] Determining a second shutdown range of the PWM shutdown device according to the DC input signal;

[0025] According to the first shutdown range, a shutdown window is set in each half cycle, and when the AC input signal is at a peak value, the PWM shut-off device is controlled by the shutdown window to be in a shutdown state;

[0026] According to the second shutdown range, a direct feedback window of voltage abnormality is set, and when the DC input signal is an abnormal voltage, the direct feedback window controls the PWM shutdown device to be in a closed state, and when the voltage returns to the preset second shutdown range, the PWM shutdown device is reopened.

[0027] Furthermore, the single chip microcomputer is also used for:

[0028] Get input signal and expected signal;

[0029] Determine a monitoring and counting mechanism according to the signal ripple state of the input signal; wherein the monitoring and counting mechanism is used to record the number of times the input signal exceeds a preset range;

[0030] When the monitoring counting mechanism is started, the signal nodes exceeding the expected signal in the signal ripple state are counted to determine the number of counts, and the fluctuation frequency of the input signal is determined according to the number of counts;

[0031] When the fluctuation frequency continues to increase, the effective signal duration of the input signal is determined according to the expected signal, and when the effective signal duration decreases, the PWM switch is controlled to be in a closed state;

[0032] When the fluctuation frequency continues to decrease, the effective signal duration of the input signal is determined according to the expected signal, and when the effective signal duration increases, the PWM switch is controlled to be in a default on state.

[0033] Furthermore, the single chip microcomputer is also used for:

[0034] Collect the square wave signal after the input signal is converted, and generate a square wave sequence;

[0035] Continuously monitor the square wave sequence to determine whether there is a frequency change, and based on the frequency change, determine whether the voltage of the input signal has a synchronous change;

[0036] When no synchronization change occurs, the drift delay of the clock frequency is determined according to the frequency change.

[0037] The beneficial effects of the present invention are:

[0038] The present invention directly detects input signals through the MCU, detects different input waveform signals to determine whether the AC or DC inputs are over-voltage or under-voltage, and then protects the power supply, thereby effectively improving the service life and reliability of the power supply. At the same time, since signal acquisition and control are integrated into the single-chip microcomputer, the peripheral sampling circuits of the hardware are reduced, effectively reducing the detection cost.

[0039] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0040] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 A system block diagram of an input monitoring and protection system for an LED driving power supply according to an embodiment of the present invention;

[0043] Figure 2 Input signal monitoring process for LED driver power supply in prior art;

[0044] Figure 3 It is a block diagram of the power input system of the LED driving power supply in the prior art;

[0045] Figure 4 This is an input signal monitoring flow chart of an input monitoring protection system for an LED driving power supply in an embodiment of the present invention;

[0046] Figure 5 The present invention is a signal detection circuit diagram of an input monitoring and protection system for an LED driving power supply in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0048] like Figure 1 , Figure 4 and Figure 5 As shown, this embodiment provides an input monitoring protection system for an LED driving power supply, including a single-chip microcomputer and an analog-to-digital conversion circuit embedded in the single-chip microcomputer;

[0049] The single chip microcomputer includes an analog input port and a PWM switch, the analog input port is electrically connected to the input end of the analog-to-digital conversion circuit, and the PWM switch is electrically connected to the output end of the analog-to-digital conversion circuit;

[0050] The analog-to-digital converter is used to collect the input signal of the analog input port, determine the real-time voltage value of the input signal, and judge whether the real-time voltage value exceeds the preset input voltage range;

[0051] When the real-time voltage value exceeds the preset input voltage range, the PWM switch is controlled by the single-chip microcomputer to switch off the output PWM signal.

[0052] The principle of the above technical solution is:

[0053] In the actual implementation of the present invention, in order to ensure the reliability and stability of the power supply, the existing solution usually uses a metering chip at the input signal end to manage the input signal, but this will undoubtedly increase the power supply cost.

[0054] Therefore, the present invention modifies the input detection circuit, and connects the input signal directly to the analog input port of the single-chip microcomputer after passing through the negative feedback operational amplifier, and then uses the ADC to collect the peak value, period, maximum value, and minimum value of the input signal. Then, the voltage value, frequency, and input type of the input signal can be calculated based on these values. The input voltage and frequency range of the AC / DC are limited respectively. If the range is exceeded, the single-chip microcomputer quickly shuts off the output PWM signal to achieve the purpose of protecting the power supply.

[0055] The specific implementation plan is as follows: Figure 5 As shown:

[0056] AC-L (live wire) and AC-N (neutral wire) receive input AC signals, and the AC signal of the live wire passes through the third resistor R3

[0057] After the negative feedback operational amplifier U1 is connected, the safety relay is connected through SEC to realize the control of the circuit on and off. The safety relay is triggered and disconnects the circuit only when there is an abnormality. The amplified signal of the negative feedback operational amplifier U1 also outputs the detected current, voltage and other circuit parameters through the eighth resistor R8 in the measurement section of AC-SEN, and then can be connected to the MCU control unit to realize the measurement of the voltage range.

[0058] Compared with the traditional sampling circuit, the present invention has a first capacitor C1 and a second capacitor C2 connected to the +IN input end of the negative feedback operational amplifier U1 through a second resistor R2, and these two capacitors can filter high-frequency noise and interference signals; in the absence of interference signals, the voltage range can be measured by sine waves and analog signals, and it is more accurate.

[0059] The V-input terminal of the negative feedback operational amplifier U1 is connected with a first diode D1 in parallel with the sixth resistor R6, which can protect the circuit from reverse voltage shock. Without reverse voltage shock, it is not just about measuring DC and AC. When the first diode D1 does not exist, it is impossible to prevent voltage shock, that is, when measuring, the input voltage exceeds the rated range and will be directly damaged.

[0060] The beneficial effects of the above technical solution are:

[0061] The present invention directly detects input signals through the MCU, detects different input waveform signals to determine whether the AC or DC inputs are over-voltage or under-voltage, and then protects the power supply, thereby effectively improving the service life and reliability of the power supply. At the same time, since signal acquisition and control are integrated into the single-chip microcomputer, the peripheral sampling circuits of the hardware are reduced, effectively reducing the detection cost.

[0062] As an embodiment of the present invention: the single chip microcomputer is further connected to a negative feedback operational amplifier, and the input end of the analog input port is electrically connected to the output end of the negative feedback operational amplifier.

[0063] The principle of the above technical solution is:

[0064] In actual operation, the negative feedback operational amplifier can amplify the input signal, making it easier for the analog input port of the microcontroller to process it and collect the peak and valley values ​​of the input signal.

[0065] As an embodiment of the present invention: when the input signal is an AC signal, the negative feedback operational amplifier converts the AC signal into a sine wave signal with an amplitude of 3.3V;

[0066] Among them, after the sinusoidal wave signal is collected by the analog-to-digital conversion circuit, the actual AC input voltage and frequency are determined based on the current maximum value, minimum value and time difference of the voltage, and the real-time voltage value is confirmed.

[0067] The principle of the above technical solution is:

[0068] If the input signal is AC, the input detection circuit will convert the AC signal into a 3.3V sine wave signal through the operational amplifier and input it into the analog input port of the microcontroller. Then the microcontroller collects data for at least one cycle (30ms, because the commonly used AC power is usually 50hz / 60hz) through the ADC to obtain the maximum value of the current voltage. , minimum and the time difference between the two voltages , from which the current actual AC input voltage and frequency can be calculated. The calculation formula is as follows:

[0069] (Formula 1-1)

[0070] Op amp gain:

[0071] (Formula 1-2)

[0072] AC input frequency:

[0073] (Formula 1-3)

[0074] As an embodiment of the present invention: when the input signal is a DC signal, the negative feedback operational amplifier converts the DC signal into an analog signal with an amplitude of 0 to 3.3V;

[0075] Among them, after the analog signal is collected by the analog-to-digital conversion circuit, the real-time voltage value is determined based on the current voltage value, the reference voltage value and the gain of the negative feedback operational amplifier.

[0076] The principle of the above technical solution is:

[0077] If the input signal is DC, the DC power will be converted into an analog signal with an amplitude of 0~3.3V through the operational amplifier, and then the microcontroller can get the current voltage value through the data collected by the ADC. , combined with the reference voltage value and the gain of the op amp The current actual DC input voltage can be calculated, and the calculation formula is shown in Formula 2-1: (Formula 2-1).

[0078] As an embodiment of the present invention: when the input signal is an input / output signal, the analog-to-digital conversion circuit controls the microcontroller to respond to the light control mode of the LED device based on the thresholds of input undervoltage and input overvoltage, and turns off the output PWM signal.

[0079] The principle of the above technical solution is:

[0080] After the input and output voltages are collected, the input overvoltage and input undervoltage thresholds can be set according to the actual input tolerance of the hardware. When the voltage exceeds the threshold, the microcontroller responds quickly and enters the light-off mode, turning off the output PWM signal to protect the power supply.

[0081] As an embodiment of the present invention: the lighting control mode includes: a dimming mode, a light off mode and an emergency mode.

[0082] The present invention is provided with multiple light control modes, and can feed back to the single chip microcomputer according to the light control mode, so as to realize different voltage range settings.

[0083] As an embodiment of the present invention: the single chip microcomputer is also used for:

[0084] Generate a first warning signal and a second warning signal according to the voltage sampling signal of the analog input port, the first warning signal is used to indicate that the input voltage reaches a preset value, and the second warning signal indicates that the LED device is shut down normally;

[0085] The switch control signal is adjusted according to the first warning signal and the second warning signal, wherein:

[0086] According to the effective state of the first warning signal or the second warning signal, a constant current compensation interface is set.

[0087] The principle of the above technical solution is:

[0088] In actual implementation, the quasi-input port can receive a voltage sampling signal from an input power source, and the voltage sampling signal can reflect the actual change of the input voltage.

[0089] The single chip microcomputer can generate two warning signals, namely the first warning signal and the second warning signal, according to the voltage sampling signal of the analog input port. The first warning signal is used to indicate that the input voltage has reached a preset value, while the second warning signal is used to indicate that the LED device is shut down normally. In this way, when the input voltage exceeds the safe range, a warning signal can be issued in time so that the operator can take corresponding measures in time to avoid damaging the LED lamp beads.

[0090] In addition, a constant current compensation interface can be set according to the effective state of the first warning signal or the second warning signal. The constant current compensation interface can provide a stable current output when the first warning signal or the second warning signal is effective, thereby ensuring the stable operation of the LED device. In this way, even if the input voltage exceeds the safety range, the normal operation of the LED lamp beads can be guaranteed, thereby extending their service life.

[0091] The beneficial effects of the above technical solution are:

[0092] In actual implementation, by using a single-chip microcomputer, the input monitoring protection system of the present invention can not only quickly and accurately detect changes in input voltage and issue warning signals in time to avoid damage to LED lamp beads, but also set different constant current compensation interfaces according to different warning signal states, thereby ensuring the normal operation and service life of the LED lamp beads.

[0093] As an embodiment of the present invention: when the first switch and the second switch are connected to the same resonant capacitor and the series-parallel signal is a series signal, the second switch is turned off and the first switch is turned on.

[0094] The principle of the above technical solution is to jointly control the switch state of the same resonant capacitor. In this case, when the series-parallel signal is a series signal, the second switch will remain in the closed state, and the first switch will be turned on. In this way, when the first switch is turned on, the digital coding information it carries will be used to control the switch state of the resonant capacitor, thereby achieving precise control of the resonant capacitor. At this time, the second switch remains closed to ensure that only one switch is in the open state, thereby avoiding misoperation and safety issues.

[0095] As an embodiment of the present invention: when receiving an input signal, the analog-to-digital converter determines whether it is an AC input signal or a DC input signal;

[0096] Determine a first shutdown range of the PWM shutdown device according to the AC input signal;

[0097] Determining a second shutdown range of the PWM shutdown device according to the DC input signal;

[0098] According to the first shutdown range, a shutdown window is set in each half cycle, and when the AC input signal is at a peak value, the PWM shut-off device is controlled by the shutdown window to be in a shutdown state;

[0099] According to the second shutdown range, a direct feedback window of voltage abnormality is set, and when the DC input signal is an abnormal voltage, the direct feedback window controls the PWM shutdown device to be in a closed state, and when the voltage returns to the preset second shutdown range, the PWM shutdown device is reopened.

[0100] The principle of the above technical solution is:

[0101] The switching time of the PWM circuit breaker can be adjusted according to different input signals (AC input signal and DC input signal). The analog-to-digital converter can be used to detect the type of input signal. If it is an AC input signal, then the voltage conversion can be started to realize power supply and start the LED drive power supply; if it is not an AC input signal, but a DC input signal, the circuit breaker can also be directly turned off.

[0102] Then, according to the type of input signal, the first shut-off range and the second shut-off range of the PWM shut-off device can be further determined. For the first shut-off range, a shut-off window can be set in each half cycle, and when the AC input signal is at the peak value, the PWM shut-off device is controlled by the shut-off window to be in the off state. When the input signal is an AC signal, the current can be limited by turning off the PWM shut-off device in certain time periods to avoid damage to the LED lamp beads due to excessive input voltage.

[0103] For the second shutdown range, a direct feedback window of voltage abnormality can be set according to the characteristics of the DC input signal, and when the DC input signal is at an abnormal voltage, the direct feedback window controls the PWM shutdown device to be in a closed state. When the voltage returns to the preset second shutdown range, the PWM shutdown device will automatically reopen.

[0104] As an embodiment of the present invention: the single chip microcomputer is also used for:

[0105] Get input signal and expected signal;

[0106] Determine a monitoring and counting mechanism according to the signal ripple state of the input signal; wherein the monitoring and counting mechanism is used to record the number of times the input signal exceeds a preset range;

[0107] When the monitoring counting mechanism is started, the signal nodes exceeding the expected signal in the signal ripple state are counted to determine the number of counts, and the fluctuation frequency of the input signal is determined according to the number of counts;

[0108] When the fluctuation frequency continues to increase, the effective signal duration of the input signal is determined according to the expected signal, and when the effective signal duration decreases, the PWM switch is controlled to be in a closed state;

[0109] When the fluctuation frequency continues to decrease, the effective signal duration of the input signal is determined according to the expected signal, and when the effective signal duration increases, the PWM switch is controlled to be in a default on state.

[0110] The principle of the above technical solution is:

[0111] The single-chip microcomputer of the present invention further includes a memory for storing the waveform data of the input signal and the data of the expected signal, as well as the parameters of the monitoring and counting mechanism. When the waveform data of the input signal changes, the single-chip microcomputer can write the corresponding waveform data into the memory. At the same time, when the monitoring and counting mechanism is started, the single-chip microcomputer can read the data in the memory and calculate the parameters of the monitoring and counting mechanism accordingly.

[0112] Based on the waveform data and the expected signal data, the MCU can determine the parameters of the monitoring and counting mechanism, including the number and location of the unexpected signal nodes. When the waveform data of the input signal changes, the MCU will monitor these changes and calculate the parameters of the monitoring and counting mechanism accordingly.

[0113] When the monitoring counting mechanism is started, the microcontroller will count the waveform data of the input signal and record the number of times each count occurs. In this way, the microcontroller can obtain the fluctuation frequency of the input signal and calculate the fluctuation amplitude of the input signal accordingly.

[0114] When the fluctuation frequency of the input signal continues to increase, the microcontroller can determine that the effective signal duration of the input signal is decreasing, and there may be a situation where the input signal is no signal. At this time, the microcontroller can control the PWM shutdown device to be in the off state to prevent the input signal from having an excessively high voltage, thereby avoiding damage to the LED lamp beads.

[0115] When the fluctuation frequency of the input signal continues to decrease, the microcontroller can determine that the effective signal duration of the input signal is increasing and may resume normal working state. At this time, the microcontroller can control the PWM shutdown device to be in the default on state to ensure that the LED lamp beads have sufficient current supply.

[0116] As an embodiment of the present invention: the single chip microcomputer is also used for:

[0117] Collect the square wave signal after the input signal is converted, and generate a square wave sequence;

[0118] Continuously monitor the square wave sequence to determine whether there is a frequency change, and based on the frequency change, determine whether the voltage of the input signal has a synchronous change;

[0119] When no synchronization change occurs, the drift delay of the clock frequency is determined according to the frequency change.

[0120] The principle of the above technical solution is:

[0121] In the implementation process of the present invention, the square wave signal after the input signal conversion is collected, and a square wave sequence is generated. Specifically, when the input signal changes, the single chip microcomputer can sample it and convert the sampling result into a square wave sequence. These square wave sequences can reflect the waveform change of the input signal, which is helpful for further analyzing the state of the input signal. The square wave sequence is continuously monitored to determine whether there is a frequency change, and according to the frequency change, it is determined whether the voltage of the input signal has a synchronous change. Specifically, the single chip microcomputer can continuously monitor the generated square wave sequence to determine whether its frequency has changed. If the frequency changes, it means that the voltage of the input signal has also changed accordingly. At this time, the single chip microcomputer can judge the voltage change of the input signal by comparing the original waveform data of the input signal and the converted square wave sequence. When no synchronous change occurs, the drift delay of the clock frequency is determined according to the frequency change. Specifically, when the voltage of the input signal does not change synchronously with the frequency change of the square wave sequence, the drift delay of the clock frequency of the input signal can be determined according to the frequency change of the square wave sequence. This delay value can help the single chip microcomputer better track the state of the input signal and can be used to predict future voltage changes.

[0122] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An input monitoring and protection system for LED driving power supply, characterized in that: Including a single-chip microcomputer and an analog-to-digital conversion circuit embedded in the single-chip microcomputer; The single chip microcomputer includes an analog input port and a PWM switch, the analog input port is electrically connected to the input end of the analog-to-digital conversion circuit, and the PWM switch is electrically connected to the output end of the analog-to-digital conversion circuit; The analog-to-digital converter is used to collect the input signal of the analog input port, determine the real-time voltage value of the input signal, and judge whether the real-time voltage value exceeds the preset input voltage range; When the real-time voltage value exceeds the preset input voltage range, the PWM shut-off device is controlled by the single-chip microcomputer to shut off the output PWM signal; The single chip microcomputer is also used for: Get input signal and expected signal; Determine a monitoring and counting mechanism according to the signal ripple state of the input signal; wherein the monitoring and counting mechanism is used to record the number of times the input signal exceeds a preset range; When the monitoring counting mechanism is started, the signal nodes exceeding the expected signal in the signal ripple state are counted to determine the number of counts, and the fluctuation frequency of the input signal is determined according to the number of counts; When the fluctuation frequency continues to increase, the effective signal duration of the input signal is determined according to the expected signal, and when the effective signal duration decreases, the PWM switch is controlled to be in a closed state; When the fluctuation frequency continues to decrease, the effective signal duration of the input signal is determined according to the expected signal, and when the effective signal duration increases, the PWM switch is controlled to be in a default on state.

2. An input monitoring and protection system for LED driving power supply as claimed in claim 1, characterized in that: The single chip microcomputer is also connected to a negative feedback operational amplifier, and the input end of the analog input port is electrically connected to the output end of the negative feedback operational amplifier.

3. An input monitoring and protection system for LED driving power supply as claimed in claim 2, characterized in that: When the input signal is an AC signal, the negative feedback operational amplifier converts the AC signal into a sine wave signal with an amplitude of 3.3V; Among them, after the sinusoidal wave signal is collected by the analog-to-digital conversion circuit, the actual AC input voltage and frequency are determined based on the current maximum value, minimum value and time difference of the voltage, and the real-time voltage value is confirmed.

4. The input monitoring and protection system for LED driving power supply according to claim 1, characterized in that: When the input signal is a DC signal, the negative feedback operational amplifier converts the DC signal into an analog signal with an amplitude of 0 to 3.3V; Among them, after the analog signal is collected by the analog-to-digital conversion circuit, the real-time voltage value is determined based on the current voltage value, the reference voltage value and the gain of the negative feedback operational amplifier.

5. The input monitoring and protection system for LED driving power supply according to claim 1, characterized in that: When the input signal is an input / output signal, the analog-to-digital conversion circuit controls the single-chip microcomputer to respond to the light control mode of the LED device based on the thresholds of input undervoltage and input overvoltage, and turns off the output PWM signal.

6. An input monitoring and protection system for LED driving power supply as claimed in claim 5, characterized in that: The lighting control modes include: dimming mode, light off mode and emergency mode.

7. The input monitoring and protection system for LED driving power supply according to claim 1, characterized in that: The single chip microcomputer is also used for: Generate a first warning signal and a second warning signal according to the voltage sampling signal of the analog input port, the first warning signal is used to indicate that the input voltage reaches a preset value, and the second warning signal indicates that the LED device is shut down normally; The switch control signal is adjusted according to the first warning signal and the second warning signal, wherein: According to the effective state of the first warning signal or the second warning signal, a constant current compensation interface is set.

8. The input monitoring and protection system for LED driving power supply according to claim 1, characterized in that: When receiving an input signal, the analog-to-digital converter determines whether it is an AC input signal or a DC input signal; Determine a first shutdown range of the PWM shutdown device according to the AC input signal; Determining a second shutdown range of the PWM shutdown device according to the DC input signal; According to the first shutdown range, a shutdown window is set in each half cycle, and when the AC input signal is at a peak value, the PWM shutdown device is controlled by the shutdown window to be in a shutdown state; According to the second shutdown range, a direct feedback window of voltage abnormality is set, and when the DC input signal is an abnormal voltage, the direct feedback window controls the PWM shutdown device to be in a closed state, and when the voltage returns to the preset second shutdown range, the PWM shutdown device is reopened.

9. The input monitoring and protection system for LED driving power supply according to claim 1, characterized in that: The single chip microcomputer is also used for: Collect the square wave signal after the input signal is converted, and generate a square wave sequence; Continuously monitor the square wave sequence to determine whether there is a frequency change, and based on the frequency change, determine whether the voltage of the input signal has a synchronous change; When no synchronization change occurs, the drift delay of the clock frequency is determined according to the frequency change.

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