LED driving power supply anti-surge system

Abstract

The invention discloses an LED driving power supply anti-surge system which comprises a low-frequency surge voltage suppression circuit, a high-frequency surge residual voltage monitoring circuit, a high-frequency surge residual voltage suppression circuit and a peak surge residual voltage absorption circuit. A pi-type LC filter network composed of inductors L2-L3 and capacitors C3-C5, a low-frequency surge voltage in a direct-current LED driving power supply signal output by a field-effect tube Q1 falls to the ground, an operational amplifier AR1 compares a forward high-frequency surge voltage in the direct-current LED driving power supply signal with a voltage value obtained after voltage division of a resistor R7 and a resistor R8 so as to monitor a voltage value of a high-frequency surge residual voltage, inductors L4-L5 and capacitors C9-C10 are utilized to form an LC low-pass filtering network, the forward high-frequency surge voltage in the direct-current LED driving power supply signal falls to the ground, and the peak surge residual voltage in the direct-current LED driving power supply signal is released to the ground by a diode D14, so that the surge voltage induced by electromagnetic interference in the LED driving power supply circuit can be inhibited, the use safety of an LED is ensured, and ideal and stable luminous intensity is achieved at the same time.

Description

technical field [0001] The invention relates to the technical field of LED driving power supply, in particular to an anti-surge system for LED driving power supply. Background technique [0002] In the application process of LED, because the current of the driving power supply is too strong, it will cause the attenuation of the LED, and when the current is too weak, it will affect the luminous intensity of the LED. Therefore, the characteristics of the LED itself determine that the driving power supply needs to output a stable current to ensure The service life of LED and the safety of use; LED drive power is usually input from the mains, transformed by a transformer, and then converted into a stable DC LED voltage by a rectifier and voltage regulator module, for a constant current source to output a stable current; [0003] However, in the use of LED drive power, transient overvoltages are often generated due to external interference such as grid load sling, lightning strik...

AI Technical Summary

Problems solved by technology

[0003] However, in the use of LED drive power, transient overvoltages are often generated due to external interference such as grid load sling, lightning strikes, electromagnetic interference, etc., which are called surge voltages. The output voltage of the voltage module fluctuates, which causes the output current to fluctuate, making the brightness of the LED unstable when it is working, thus affecting the service life of the LED, and even damaging the electronic components and burning the circuit in severe cases; the surge voltage is pulsed, Its main energy is concentrated in the low frequency part, but even if the high frequency energy contained in the surge waveform is relatively small, it is enough to affect the normal operation of the LED;

[0004] In the prior art, the surge protection method is usually to directly connect a surge absorbing device or an overvoltage protection device in parallel with the LED drive power supply, so as to absorb or transfer energy to the surge voltage exceeding the withstand capacity of the LED drive power supply. However, the surge voltage induced by the circuit in the LED drive power supply in real time due to electromagnetic interference cannot be suppressed; although the surge voltage induced by electromagnetic interference is not as large as the surge voltage generated by lightning strikes, it will cause LED damage. Unstable brightness during work, reducing the service life of LEDs

Images