The design technology LED PCB board

We have some advice for layout designer of LED PCB board.
①In design, the ground layer and power layer were separated and echo has a layer.There are has been a decrease in inductance between the ground layer and power layer.

②reduce the segmentation of ground layer and power layer, this will reduce the inductance and Increase the stable for LED PCB circuit.
③Shorten the connect wire length between the drive circuit and LED,this also will Reduce the inductance of conductor.

④ 10 uF Tantalum Capacitor and 0.1uF monolithic ceramic capacitor be located close to LED drive signal source. This will reduce noise and increase led response time.

Make white light with ultraviolet led and Fluorescent powder (test partⅠ)

The uv led plus a little Fluorescent powder could set the white light .uilt now, there are has a lot researcher to make this experiment till the present moment. We will share that test result with you.
we got new spectrum in pic 1 with 365nm uv led strip plus TCB(TCB as three basal color—red,green,blue)’ Fluorescent powder.

TCB’ Fluorescent powder brings out new spectrum by 365nm ultraviolet led

The pic2 display that coordinate of white light in CIE colorimeter diagram . standard light source along by it’s side.

○ as white light location  ●as standard light source location

The problem of high power led module

Some problem we have to face when Use the high power led module
* color chromatic aberration of led
There are no problem when use just only a led module, this problemAppear in led module of mass product.
*pulse of LED
In fact I did run into this problem , main reaction in powered on.but
I does not recognize that them are static electricity.
*Light angle of LED
Different led lens has different light angle, their effects become completely different.
*LED dissipation
In theory led is cold light source, it generates no heat. But everyone know that this is problem
*LED efficiency
At currently ,the change efficiency of LED is relatively low.

Color tone

Now The thought wavelength was more convenient for research light properties . we had visible Spectrum formed a circuit. And divide into nine area (please see picture 1), also call color ring.

The number on color means wavelength of color corresponding , the unit as nm, any two type fan color at the top of color top are each other’s complementary color . blue （ 435 ～ 480nm ） complementary color is yellow （ 580 ～ 595nm ）。In other words: Yellow: Minus-blue subtractive primary used in the three-color process. By studying the color tone has other characters as follows:

*We can get white color through mixed complementary color: for example mixed blue color and yellow color we get white, mixed yellow color and cyan color we also can get white;

*Whatever sort color on color ring you can mixed the color with the adjacent two kind color.

*The sun shines on an object . some wavelength is absorption by object. We have seen The color of object(reflect light) is complementary of Color tone .

Various types of led strip power

How to calculate the led strip power? The datasheet of led strip provides a theoretical answer to this question. And we know from over here. the 1 meter ( 3ft) led strip power is 14.4W. How to compute the result . the calculate formula as follows:
The power of echo pcs SMD5050 led module is 0.24 watt. and there are have 60 LEDs on 1 meter(3ft). 0.24Watt *60LEDs =14.4Watt/meter(3ft)。we just need to know individual led power and led quantity (1meter or 3 ft). then we can calculate the total power. Next topic: different bind led module has different parameter(LED power). Now for a quick look at some of the other module power.
LED package         Power

SMD3528              0.08W

SMD5050             0.24W

SMD2835             0.1W

SMD3014             0.1W

SMD4014             0.225W

As mentioned above, The parameter of led power from datasheet, it was just theory . in fact, we can’t use the full power to run led strip. In other words we will be limited to be less than this value. We use only the 12watt about when the theory value is 14.4watt. the experience from led detect device. We call it actual measurement .

Actual measurement power = theory power * 80%

The LED’s relationship between current and voltage

The simply drive way of led as current limiting by resistor.That said, the input voltage via the resistor connected to LED. LED can made constant light When work voltage remains constant. You can get the strength of light the you want by adjusting the values of resistor
Now,In this example,We’ve got through a standard 5mm LED to expounds mutual coordination between current and voltage. The figure shows function curves between the operation voltage (VF) and Forward current(IF)。We are aware of the concept from picture as follows.this forward voltage change tendency increased with the increase of forward current。Now we will take an example.
the green led work at 10mA. The work current counterpart was the constant voltage 5 volt. . the calculate formula of series resister as (5V -VF,10mA)/10mA = 300 ohm。

The stand LED of Red light 、green light 、and yellow light has forward voltage range from 1.4V to 2.6V。the forward voltage slightly changes the several hundred when the forward current is low than 10mA.

Infrared ray .

In light spectrum，wave length from 0.75 to 1000 um is called infrared light ，also call infrared ray. The infrared belong to the field of electromagnetic wave and just like ir led strip。The infrared ray. Possessing special electromagnetic wave function 。 the application of infrared can be seen everywhere. Such as: Through the absorption of infrared ray. and reflection of visible light, fluorescent brightening agents ( FBA) can enhance the whiteness and brightness of fabrics.
the range of infrared ray’s very wide .the infrared ray was divided by different wavelength. They divide them into three type：

*Near infrared ray: It is most commonly used for Breast disease; General investigation. Such as Near infrared ray scan.

*Middle infrared：This is wavelength are high temperature sensitive. it can be applied to new developments in detect temperature technology.

*Far infrared: also known as live light. it have a positive effect on the human . it can boost the subcutaneous temperature， Effectively improve the physique, cleanse the blood and the activate cells. Bring in that health change , can cleanse your blood and other substances which is harmful. 。beneficial to human health and other substances which is harmful.

Theory of white LED

In fact，LED was through electric energy changing into light energy. Then can have a light of red, yellow , blue ,green, cyan , orange , purple or white . in here , we used most in led as white led. The white led don’t like other color led, the white led was composed of blue light and yellow .let’s

Talk about theory of white led.
There have a led chip in led module, first let it created blue light(The ultraviolet light or blue light is then converted to visible light by phosphors on the surface of the discharge tube.), then yellow light generated by phosphor excitation. They blend into a color .that’s white led.

The proportion of Color matching has something special technology point to share. For example:

If We’re going to be increasing the volume of blue light , the led will look more white . if you would like more warm white, so you should be possible to reduce proportion from blue light.

This is The influences of white light LED packaging process.

Today, population growth raced ahead on the earth, A.an overpopulated earth will be unable to sustain its inhabitants. because we needs bread, We need food and water for survival. However the arable land and water resource just gonna get more and more tense! Luckily, We know how to use technology To solve this problem.Agriculture cultivation will not restricted by natural condition.
First we all know that plant require water and sunshine to grow. We have replaced sun light with LED. and put them into special live space.

There are have water and light. And intensity of light and frequency is adjust accord to grow status echo plant. So the effect of photosynthesis is best that sun light.

The conception of uv led strip light energy & power density

l                Light energy : light energy refer to The variation of the light distribution in object or space. The uv light energy is now express in MJ/CM2 ，the light energy integrator are used for measuring light energy. Some factory indicates irradiation range with light energy. In generally , the curing condition shall meets that (800-1200)MJ/CM2。Other way equipped with shell uv led is not applicable to this case..

l                The power density of uv led mean by power is required between two centers of the UV led . represents with W/CM .