Forced constant flow source dimming LED (Light Emitting Diode) lamp

Abstract

The invention discloses a forced constant flow source dimming LED (Light Emitting Diode) lamp comprising an alternating current (AC) power source, an AC-DC (Direct Current) rectifier filter circuit, a DC-DC constant-voltage circuit, a DC-DC constant-current driving circuit, a PWM (Pulse Width Modulation) dimming signal generator, an LED load and a load short-circuit protection circuit, wherein the AC-DC rectifier filter circuit is used for rectifying and filtering an AC voltage output by the AC power source and outputting a DC voltage to the DC-DC constant-voltage circuit for voltage stabilization so as to output a constant DC voltage to the DC-DC constant-current driving circuit; the DC-DC constant-current driving circuit is used for carrying out constant-current transformation on the DC voltage output by the DC-DC constant-voltage circuit to output a constant current to the LED load and is also used for dimming the LED load under the action of a PWM signal output by the PWM dimming signal generator to dim a forced constant-current source of the LED load; the load short-circuit protection circuit is connected between the LED load and the PWM dimming signal generator and sends a control signal to the DC-DC constant-current driving circuit when detecting that the LED load is in a short-circuit state, so that the output of the constant current to the LED load is stopped.

Description

technical field [0001] The invention relates to the field of LED driving, in particular to an LED lamp dimmed by a forced constant current source. Background technique [0002] LED lighting technology has the advantages of energy saving, environmental protection, long life and easy control, and is one of the most promising high-tech fields in the 21st century. Under the bright prospect of the LED lighting industry, the driving power supply of various LED lamps is also developing rapidly for different applications in the lighting field. Most of the existing LED driving power supply adopts switching power supply technology. With the development of technology, a drive circuit with an isolated structure and a power factor correction (PFC) function appears, which greatly improves the reliability and power utilization efficiency of the LED drive circuit. In addition, the characteristics of LED determine that to keep its brightness constant and prevent burnout, it is an ideal meth...

AI Technical Summary

Problems solved by technology

[0003] The resonant LED drive power supply is the most widely used isolated LED drive power supply on the market, but the structure of this LED drive circuit is complex and the cost is high

Patent ZL 200820062043.2 proposes a flyback LED drive circuit, but the drive circuit is still a constant voltage power supply

In addition, during the working process, the LED load driven by the LED drive circuit may produce abnormal phenomena, such as short circuit. If this happens, many components inside the drive circuit will be damaged, and in severe cases, it will cause fire and explosion. and other security incidents

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