In order to achieve adjust color temperature, set conduction voltage drop of Cool white、 warm white led module with input voltage to the same . use power transistors(MOS1& MOS2) to control open and closed for the Cool white、warm white led module . The signal of PWM2 interfaced GATE of MOS1to control Cool white led array . The signal of PWM3 interfaced GATE of MOS2 to control warm white led array.

Operation process：

Each of the first and second switches alternatively performs a turn-on operation and a turn-off operation. First cool white led array is turn-on when PWM2 as high logic level and or PWM3 as low logic level . Then to do the opposite。 the warm white led array is turn-on and the cool white led array is turn-off. Use the duty-cycle of PWM to modulate the turn-on time of Cool white、 warm white led module . Linear LED dynamic display system based on linetype array, which is the effect of persistence of vision, is manufactured. So can implement the effects of change Of color temperature.

Comprehend such basic concept concepts of optical engineering

The first and most important concept was Luminous flux & light-illuminance and light- lightness .The basic concept and definition of optical engineering are presented in this paper. We are walk way too much: about concept before . Perhaps I can give you a brief explanation, outlining The main points today.

In ordinary language：

Luminous flux as how many light had been granted（Add up all the light）

light-illuminance refers to how much light was reverberation of object ‘average surface.

light- lightness means: If light is not completely absorbed by the object, some light is said to be reflected. returns a specified part of light — We called them light- lightness.

The unit of Luminous flux is Lm , the unit of light-illuminanc is Lux. the conversion relation of them is: 1 lm illumination in 1 square meter of a surface. its 1 lux at this point. The unit of light- lightness is candela. highlight intensity of candela in a solid angle,within this range the total highlight intensity —- we take it as 1 lm.

Research of knowledge point LED lumens
According to concept to know:
Cover the same ground from different angles to know that led lumens. What “Lumen” meant?
Okay, More seriously, the lumen represents the intensity of light,which is the luminous flux. In short, the lumen is light in the amount of the object surface. The equation is simple:research Led lumens new concept. The amount of light to shine on object surface ,call “lumen”.So The lumen is the luminous flux unit.

How to support Night vision surveillance camera with ir led strip

Night viewing device in Dark night; Let’me see how it did work.We recognize that Night viewing camera can captured the scene in night. Such as shooting wildlife or CCTV (Closed-circuit television). Because it can see everything clearly with camera in night.And the people have been so lost that I could not see. The reason for this ir led strip to help it finish all work. When close the Infrared filter, As we have seen that The infra-red rays reflected from the forms image. and not the visible light reflected from the forms image. So the Night vision surveillance camera can they take in their photos in Dark night. The ir led strip mainly a matter of Night vision surveillance camera . we can understand that ir led based on voluntary irradiation.