Anti-surging switching power supply and corresponding light emitting diode (LED) driving circuit

Abstract

The invention relates to an anti-surging switching power supply, which comprises a rectification circuit, a voltage transformation circuit and an anti-surging circuit, wherein the voltage transformation circuit comprises a switching tube Q1 and a transformer T1; the anti-surging circuit comprises a thyristor D1, a resistor R1 and a capacitor C1; two ends of the thyristor D1 are respectively connected with a main winding of the transformer T1 and the rectification circuit; one end of the capacitor C1 is respectively connected with one end of the transformer T1 and one end of the resistor R1; the other end of the capacitor C1 is connected with the rectification circuit; the other end of the resistor R1 is connected with the rectification circuit; the input end of the switching tube Q1 is connected with the main winding of the transformer T1; and the output end of the switching tube Q1 is connected with the rectification circuit. The invention also relates to a light emitting diode (LED) driving circuit. A soft starting circuit for preventing surging current is arranged, so that high current does not flow towards a key device of the switching power supply when the switching power supply is turned on; and after a certain period of time, the switching power supply is turned on to work and can run normally and reliably.

Description

technical field [0001] The invention relates to the field of drive circuits, more specifically, to a surge-proof switching power supply and a corresponding LED drive circuit. Background technique [0002] The quality index of switching power supply should be based on safety and reliability as the first principle. Under the condition that the electrical technical indicators meet the requirements of normal use, in order to make the power supply work safely and reliably in harsh environments and sudden failures, various protection circuits must be designed. Most of the input circuits of switching power supplies use capacitor filter rectifier circuits. At the moment when the incoming power supply is switched on, since the initial voltage on the capacitor is zero, a large surge current will be formed at the moment of capacitor charging, especially for high-power switching power supplies. The filter capacitor with larger capacity can make the surge current more than 100A. Such a...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide an anti-surge switching power supply and a corresponding LED drive circuit for the defect that the current of the existing switching power supply is large when the power is turned on and the key components are damaged due to the large surge current

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