Slow start circuit and LED power supply device

Abstract

The embodiment of the invention discloses a slow start circuit and an LED power supply device, the LED power supply device is connected with an LED lamp string, and the LED power supply device comprises a power supply input circuit, a power supply control circuit and the slow start circuit; the power supply input circuit rectifies and filters commercial power and then outputs a first power supply voltage and a second power supply voltage; the slow start circuit performs internal power supply after stabilizing the first power supply voltage, and outputs a pulse width modulation signal to the power supply control circuit after delaying a preset time when detecting that the internal power exists; and the power supply control circuit converts the second power supply voltage into power supply voltage according to the pulse width modulation signal to supply power to the LED lamp string, and controls the LED lamp string to gradually brighten. Power supply to the LED lamp string is delayed through the slow start circuit, and the impact current when the LED lamp string is just powered on is limited; and the LED lamp string is gradually brightened, so that eyes can gradually adapt to the LED lamp string, and the lighting effect is milder. Therefore, the problem that an existing LED power supply module cannot be started slowly at fixed time to light an LED lamp is solved.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a slow start circuit and an LED power supply device. Background technique [0002] There are three common existing LED power module solutions, the first one is AC to DC circuit (AC-DC, using constant voltage chip) plus single-chip microcomputer or DC to DC circuit (DC-DC, using constant current dimming chip) , the second is AC to DC (AC-DC, using a constant current chip) plus a flicker-removing chip and a switching dimming circuit, and the third is AC to DC (AC-DC, using a constant current chip) plus It should be placed in the conversion dimming circuit, and the single chip microcomputer should be used in the conversion and dimming circuit to control it. [0003] However, these methods are to directly light up the LED lights after power-on, and then adjust the light; the LED lights cannot be turned on after a period of delay, which will cause all lights to be turned on direc...

AI Technical Summary

Problems solved by technology

[0005] In view of the above-mentioned technical problems, the embodiment of the present invention provides a slow start circuit and LED power supply device to solve the problem that the existing LED power supply module cannot start slowly and light up the LED light at regular intervals

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