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A PWM signal duty cycle control method and corresponding circuit and LED lamp

A PWM signal and LED light technology, applied in the field of integrated circuits, can solve the problems of poor visual effect of human eyes, brightening, non-linear light change, etc., and achieve the effect of linear fading function

Active Publication Date: 2020-10-02
LINEARIN TECH CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Some high-end LED lamps support the fade-in function, and it is necessary to realize the function that the LED lamp gradually brightens when starting up. Generally, the duty cycle of the PWM signal is gradually increased to realize the LED lamp’s fade-in function. However, due to the brightness of the LED lamp and the The duty ratio of the PWM signal has a logarithmic relationship, that is, assuming that the duty ratio of the PWM signal increases linearly, the brightness of the LED light will quickly brighten when the PWM starts to increase, and the brightness will change more and more slowly in the later stage. As a result, the non-linearity of light changes leads to poor visual effects of the human eye.

Method used

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  • A PWM signal duty cycle control method and corresponding circuit and LED lamp
  • A PWM signal duty cycle control method and corresponding circuit and LED lamp
  • A PWM signal duty cycle control method and corresponding circuit and LED lamp

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Embodiment Construction

[0034] The present invention will be further elaborated below by describing a preferred specific embodiment in detail in conjunction with the accompanying drawings.

[0035] The present invention proposes a PWM signal duty cycle control method for LED lamps, which makes the duty cycle increase process of the PWM signal used for dimming in the LED lamp control circuit include N time periods, wherein the PWM signal in each time period The duty cycle of the signal increases in a linear manner, the time length of the latter time period is 1 / 2 of the previous time period, and the duty cycle of the PWM signal increases at the same time in each time length, so that the duty cycle of the PWM signal is close to the index The form changes, so as to realize the linear fading function of LED lights from a visual point of view.

[0036] Such as figure 1 Shown is the ideal exponential curve diagram of the PWM signal duty cycle increase required by the gradual light function of the above-me...

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Abstract

The invention discloses a PWM signal duty ratio control method, which comprises: there are N time periods in the duty ratio increase process of the PWM signal used for dimming in the LED lamp control circuit, wherein the PWM signal in each time period The duty cycle increases in a linear manner, and the time length of the latter time period is 1 / 2 of the previous time period, and the duty cycle of the PWM signal in each time length increases the same, so that the duty cycle of the PWM signal changes close to an exponential form , so as to realize the linear fading function of LED lights from a visual point of view.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a PWM signal duty cycle control method, a corresponding circuit and an LED lamp. Background technique [0002] LEDs have been widely used as lighting sources, and intelligent lighting products with dimming and color adjustment functions are gradually becoming popular. PWM (Pulse Width Modulation) dimming technology is the most widely used technology. It adjusts the on-off time ratio of LED lights by changing the duty cycle of the PWM signal, and realizes the dimming function through the afterglow effect of the human eye. Some high-end LED lamps support the fade-in function, and it is necessary to realize the function that the LED lamp gradually brightens when starting up. Generally, the duty cycle of the PWM signal is gradually increased to realize the LED lamp’s fade-in function. However, due to the brightness of the LED lamp and the The duty ratio of the PWM signal...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H05B45/10H05B45/325H05B44/00
CPCH05B45/10Y02B20/30Y02B20/40
Inventor 朱金桥
Owner LINEARIN TECH CORP