Embedded Interface – LED

LED (Light Emitted Diode)

Symbol

How to Identify the LED’s Positive and Negative Leads ?

• Long lead is positive(+) and small lead is negative(-)
• Round circle lead is positive(+) and flat lead is negative(-)

LED Chemical Substance

Summary of LED’s Colors and Common Chemistries

Color	Wavelength	Materials
Amber	605-620 nm	Gallium arsenide phosphide, Aluminum gallium indium phosphide
Blue	430-505 nm	IInGaN (Indium Gallium Nitride), Gallium nitride, Silicon carbide, Sapphire, Zinc selenide
Green	550-570 nm	Aluminum gallium phosphide, Gallium nitride
Infra-Red	850-940 nm	Gallium arsenide, AL GaAs (Aluminum Gallium Arsenide)
Red	630-660 nm	AL GaAs (Aluminum Gallium Arsenide), Gallium arsenide phosphide, Gallium phosphide
Ultraviolet	370-400 nm	Indium gallium nitride, Aluminum gallium nitride
Violet	410-420nm
Yellow	585-595 nm	Aluminum gallium phosphide, Gallium arsenide phosphide, Gallium phosphide

Light wave length

WaveLenth	LED APPLICATION
410nm-420nm(violet)	Skin therapy
430nm-470nm(blue)	Dental curing instrument
470nm(blue)	White LED’s using phosphor, blue for RGB white
520nm-530nm(green)	Green traffic signal lights, amber for RGBA white lights
580nm-590nm(amber)	Red signal lights, red for RGBA white lights
630nm-640nm(red)	Blood oximetry
660nm(deep red)	Skin therapy
680nm(deep red)	Night vision illuminators and beacons for use with night vision goggles or CCD’S
800nm-850nm(near IR)	Photo electric controls
940nm(near IR)	Convert illumination CCD based systems

Reference  : http://www.goldwynled.com/knowledge-bank/leds-basics

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GLOW LEDs

Application

• Status Indicator
• WiFi Router Status Indicator (Blink LEDs-Internet Status)
• Charge level Indication in mobile power-bank [Blink LEDs – Single RGB LEDs or Multiple Color LEDs)
• Bike Automation
  • Bike Turn Indicator (LED Blink – while turned)
  • Bike Side stand indicator (LED Glow -if Side stand is not took)
• Car Automation
  • Car Turn Indicator (LED Blink – while turned)
  • Car Door Status indicator(LED Glow -if Door is not close or opened)

LED Examples

• ON/OFF
• Blink using the Delay Function
• Blink using the Timer Function
• Status Indicator(Using condition Check)Button

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