The led power supply is import device for LED. led will be damage if reflect connect in led power supply. some suggestions and reform measures to prevent this kind of accidents are proposed. the reflect protect circuit that can help to avoid making mistakes. but the solution has has both advantages and disadvantages.
Advantages：
The construction is simply(please see pic as follows).
Designer the parameters based on the PN junction theory for this purpose.
Disadvantages:
There is an underlying apprehension. there are have a voltage drop(0.7V)when diode was work. the diode temperature increase as the work current increases. for example:
Diode voltage:0.7V
Input work current:2A
Pd＝2A×0.7V＝1.4W，
The junction temperature is gathering force when increase current(total power).Analyzed the influence of rising the junction temperature of pn junction. upon performance of diode;So you will see that there are both advantages and disadvantages to using Diode in solution.
Test condition:
When using the follows methods of testing led, they include luminous flux、luminous efficiency、radiation fluxes、radiation efficiency、light intensity. Luminous flux:
Test of luminous flux has two kind of methods: Integrating spheres and goniophotometer ; goniophotometer is a very precise measurement. but it takes a long time to test led. in general we using the Integrating spheres to finish test work . the Integrating spheres are has two kind test construction : one which is to put led resource into the sphere centre and the other is to put led resource into the spherical wall Integrating spheres:
Different source of flux in the space out the distributions differ. now we measuring LEDs luminous flux with integrating spheres. a measure of luminous flux per unit area.The possible reasons for the self-absorption duration difference for different led resource were diversity . self-absorption correction by Auxiliary lamp is a well-optimized solutions .
There still exists two bottlenecks in researched and development of UV(UV-B and UV-C LED) led. the second problem is high price and low led output power. so that is become very difficult to business marking. but the uv led had improved somewhat, the uv led luminous radiation began expanding to 176.6mw. It really makes a big difference(in the context of the industry it is a big achievement.) we need to have some better explanation.
So now we try to analyzes comparatively the difference between characteristic parameters of different factory.
Test object: LED lamp, semi-finished and finished products of the LED
Reference standard: industry experience.
Test method:
1、The user will bring out five LED place into Test room & 61 degrees Fahrenheit.
2、Connection of input power(the input voltage set at the maximum input voltage rating.)
3、Power on and keeping lit led 24 hours. check LED lamp for damage and thermal deformation.(cracks) in test period .
4、After lit led test, began to impact-damaged experiments:
The tester through electrical to the control LED switched between on and off. do so continuously throughout . Test period as: LED ON:20 second LED OFF:20 second Test Times:100
Test conclusions:
Ⅰ、After Test of high temperature high voltage. When those occurs: Surface paint removal, discoloration, cracking, deformation of the material. it is a failure as an LED product.
Ⅱ、After Test of impact-damaged, The LED cannot appear: current leakage or led did not work.
Analysis Method in Pathogens Detection with uv led
Several methods to monitor and identify microorganism with uv led strip.
We know that UV led strip are used in Pathogenic Microorganism Detection and Research.. By means of the uv led method one can measure the Coliform bacteria in test compounds(also can use for enumerating Coliform bacteria in water and food.) .
We can analyze what it does, To confirm the result ,the tester must culture a colony of bacteria.such as Escherichia coli, and packed into the incubator for live bacteria counting culture . they create fluorescent species(The mechanism of fluorescence reaction has been studied.). we can start check checking work with uv led.
How to changing led color temperature ?
Everyone know that led can adjust light and color temperature. the light control and adjust led light are already familiar .what was the matter with changing led color temperature.
We are take the ceiling light for example. the ceiling light has two channel to output. one channel is warm light(color temperature as 3000k), other channel is cool light(color temperature as 7000k).the two channel are all individuals and should be treated as such. the controller via output different sizes light for echo channel, can be controlled during the whole color temperature output process. for example: A channel is warm light and color temperature is 3000k，but light PWM will output only 10%，
in addition B channel is color light，but light PWM will output also only 40%，the two channel put together mixes of 3000k and 2000k,the ceiling light gained a new color temperature.
Application of UV led in Water Treatment
Water dealt with by UV led strip: especially in wastewater treatment , Application of UV led strip is necessary . All industrial chemical plants produce waste effluents.Thousands of tons of filth and sewage pour into the Ganges every day. For many years uv led has been the major Sterilizing facilities used in water and wastewater treatment plants. traditional ultraviolet ray lighthasshortcomings and adept in correction.. firstly, there are have too much ballast,this is the case ,Electronic Circuit and control part can be complex. the ultraviolet ray light will stop work if a led break down . there have two kind of uv led :254nm and 365nm respectively. where the generally used wavelength are the 254nm. Its action is: the uv light generate Hydroxyl mineralization to degrade and clear germs.
Selection of color temperature
What is color temperature of led? simple express concept from simple sentence : led can generate yellow light or white light . in here the light color ,we call it color temperature , Concrete examples demonstrated the color temperature and Environmental Science .
The lower the color temperature generate red light(also call warm light).it can bring you the warm and fragrant comfortable life environment.
The high the color temperature launched blue light(also call cool light).The led color temperature to assist the concentrate on people mind.
For the above reason , Curtain of sitting room, study uses the high color temperature of LED, make person amid magical quiet gas feel well. the bedrooms and a bathroom to adopt a low led color temperature .
We’ve always ( often) find parameters (W/m2) on light Engineering cost calculation. what’s function of parameters ?how to using the parameters?
Starting with the concepts, lighting powerdensity （LPD）—The luminous intensity on unit area. This unit is per square watt （W/m2）.As the name suggests, total power of led divided by the total area of the room. then share of the result to per square
For more discussion of the topic of lighting powerdensity （LPD）.please see table as follows:
irradiation intensity（LM) and lighting powerdensity（W/m2）
