How to selecting the suitable led for your project

LED is a solid state semiconductor device. it can transform electrical energy to light energy directly. The led is a most popular light device. the follow topic will introduces parameters of led and the skill in selecting led.

LED characters

*Voltage- The input value of led is in low voltage, the range of input voltage between 2v to 4v, this is safety voltage for user, so it is appropriate for public place.
*Currently-Work currently from 0mA to 15mA, as the work currently increase gradually , and led has more bright
*Efficiency- the consumer energy was decrease eighty percent than tradition lamp.
*Appropriate- the led sharp is square with 3mm or 5mm, so the led appropriate for complex environment.
*Responsible time, The responsible time of tradition lamp is m second , the led responsible time is n second.
*Friend environment – The led has not harmful metals

The selecting in led skills

* The price is different when led bright is different
* Anti-static electrical capacity – The led has strange capacity for anti static electrical, so it has long server time. The led can use for lighting design when the anti static electrical reached to 700V
*Wavelength – The standard wavelength require . the price as growth when the customer is going to buy some led with same color
*Leak current ,The led woke at fore-ware voltage, it will make leak currently when the led woke at reveres voltage, the leak currently will effects server time of led.

The safety requirement of LED lighting
The safety requirement of LED lighting means to the led lighting can meet safety parameters in design and product,The standards can prevent dangerous

For production safety, The following step of quality check is necessary
* identifying rated voltage，frequency, power, color temperature
* lit test / function test
* voltage withstand test and insulativity test(Inspection led lighting wiring and insulativity is whether good)
* test for continuous connect to ground

Heat dissipation mechanism

The greatest threats are heat to led   the heat will not just affect electrical performance , also will damage led. the led of work for a stable and long time , this work status is key technology for led packages, so thermal analysis of LED Packages based on Heat is import for led packages

Heat dissipation mechanism

The greatest threats are heat to led   the heat will not just affect electrical performance , also will damage led.  the led of work for a stable and long time ,  this work status is key technology for led packages, so thermal analysis of LED Packages based on Heat is import for led packages

A difference between blue light and ultraviolet rays

Mary people thought the blue light is ultraviolet rays, reason is ultraviolet rays with faint blue light. follow , we will talk that blue light and ultraviolet is differentia.

Ultraviolet rays
The ultraviolet rays is general name for wavelength(10nm~400nm) in electromagnetic spectrum. the ultraviolet rays is invisible light, ultraviolet rays divide into three type wavelength: UVA,UVB and UVC.
in generally we saw light of ultraviolet rays is cross point color of ultraviolet rays and blue light.

Blue light
The blue light is complex light from sun seven light, the main wavelength of blue light is in 425-480nm, it is visible light source.   the visible wavelength of blue light is in 380～760nm. the wavelength can create an optical illusion for human’ eyes .the blue light has satisfactory static. it is wonderful light.

More information please go to www.ledlightmake.com

The led flashing led light

The flashing light tells user when the led needs repairing ,when this happens ,the led begins to flash,signaling that it’s time to repair.  if you are not making progress then look for reasons and search reason and inquires about the repair countermeasure. we analyzes the problems in business of led of break down .

*The unsteady working voltage:
When any input power equipment shutdown, overload, voltage instability . the led flash to warning to remind the attention of input power equipment of led. at the point , we need to check the running and operation of power distribution unit , ensure that the normal running of power supply for led.

*Affected by high frequencies:
The input power high frequency conducted interference sources is derived. it also causes led flash problems.

*The initial response:
The led is damaged because of its quality.

AC voltage
We know that the single AC power input voltage frequency, the internal AC to DC after,

the LED get DC voltage. still there are has differs AC input voltage from different country.

The AC voltage of USA , Japan and most of America is 110~140V.

The AC voltage of Vietnam, Korean , France, Germany , china is 210~240V.

Car led shopping guide

Waterproof:

The car user had enough time to go the carwash to wash car at least once a week. the car led could’ve been an break, when user installed a poor quality car led. so the IP67 car led are still necessary.
Dissipate heat:

Every user know that , dissipate heat is import parameters for car led quality. bad heat dissipation is inefficient.heat sink (thermal conductivity of copper has good effectheat sink)is a good cooling solution. and thermal conductivity of copper is almost twice as much aluminum to heat evenly to the external heat sink. so the thermal conductivity of copper is best choose for car led.

Brightness:

The brightness are the important parameters. the car led should have lighting, some of warning(the led could act as a warning to other driver)each of these features. the led was so weak that it couldn’t warning to anyone.

More usual LED words
1.CFL： Compact Fluorescent Lamp
2. Watt: 功率
A unit of electrical power
Rated Watt
3. Voltage: — A measurement of the electromotive force in electrical circuit
Rated Voltage
4. Luminance:
A measure of photometric brightness
5. Luminous Efficacy:
The light output of a light source divided by the total power input to that source
Incandescent ,5~22LPW,750~2K Hour
Halogen 1959年,12~36LPW, 2~5K Hour
CFL 1993年,27~80LPW, 9~10K Hour
Metal Halide 1964年,80~115LPW, 10~20K Hour
HPS 1965年,90~140LPW,10~24 Hour
Fluorescent 1939年,75~100LPW, 12~24K Hour
Mercury 50~60LPW, 12~24K Hour
6. CRI: Color Rendering Index — a lamp’s ability to render object colors.
Incandescent CRI = 100
Halogen CRI = 100
CFL CRI < 83
7. Color Temperature — expressed in Kelvins (K), is one way to describe this color tone.
2700K~3000K warm white
3500K neutral white
4100K cool white
6400K daylight
8. Current crest factor (CF) < 1.7
9. U type lamp
2U
Triple U/3U
Quad
4 U
5U….9U
10. Spiral — T4 spiral (Φ12)
T3 spiral (Φ 9) – Slim spiral
11. Candle Lamp
12. Globe Lamp
13. Bullet Lamp
14. Household -A lamp
15. PAR & R lamp
16. Frosted Lamp
17. Pilot lamp
18. Neon tubing
19. Cold cathode fluorescent lamp (CCFL)
20. Incandescent lamp
21. fluorescent lamp
22. High pressure sodium lamp
23. Metal halide
24. Spot lighting
25. Flood lighting
26. Bactericidal lamp -Ultraviolet lamp
27. Base E26, E27……
28. Lamp holder
29. Plastic housing
30. Lighting source
32. Luminous flux
33. Luminous intensity
34. Spectrum
Continuous spectrum
Line spectrum
Full spectrum
35. Lumens depreciation (evanescence)
36. Initial lumens
37. Lamp flicker
38. Wire jumper
39. Enamel-covered wire
40. Component
41. Toroidal ring
Toroidal base
42. Resistor
Metal film resistor
Carbon film resistor
43. Capacitor
Electrolytic capacitor
Metallized polypropylene film capacitor
Polypropylene film capacitor
Metallized polyester film capacitor Polyester film c
apacitor
44. Diode
Rectifier diode
45. Transistor
46. MOS
47. IC – integrate circuit (MCU）
48. Tube
Electrode
Cathode
Cathode activation
Cathode breakdown
Cathode coating
Cathode contamination （poisoning)
Cathode emission
Cathode evaporation
Cathode glow
Cathode potential
Cathode region
Cathode sputtering
Cathode –voltage drop
Anode
Anode bar
Anode current
Anode dark space
Anode potential
Anode sputtering
Anode terminal
Distance between anode and cathode
Filament
Tube’s lead wire
Filament voltage
Phosphor
Amalgam
Argon
Neon
Exhaust tube
Maximum overall diameter (MOD)
Maximum overall Length （MOL）
49. Plastic housing
Sandy finish
Gloss finish
50. Silk screen
51. Soldering dip
Solder temperature
52. Hot melt glue
50. Aging test

In this table contrasts blue led with white led