What does LED mean?

The abbreviation LED (or L.E.D.) means light emitting diode.

An LED is usually a small area (less than 1 mm²) light source. This is an electronic device made from a tiny chip of semiconductor material that emits light when an electric current passes through it.

LEDs colors

The color of a LED is determined by the semiconductor material, not by the coloring of plastic jacket (the plastic body). The plastic jacket may be colorless (clear, the standard type or transparent), milky or colored.

Depending on the composition and condition of the semiconductor material, used in the light-emitting chip, the color of the visible LED light might be different: red, orange, amber, yellow, green, blue, cold white, and warm white. The emitted LED light is so bright that it is visible even in sunlight.

The most popular type of tri-color LED has a red and green LEDs combined into one package with three leads. They are called tri-color, because by lighting up both the red and the green a yellowish-brown color can be displayed. There are also many other color combinations available nowadays.

A bi-color LED consist of two LEDs wired in “inverse parallel” (one forwards, one backwards) combined in one package with two leads. Only one of the LEDs can be lit up at a time. That type of LEDs is not so widely used as the tri-color LEDs described above.

LED’s history and development

The first LEDs were created in the beginning of the 20th century, but the first practical visible-spectrum LED was developed in the 1960s and was red. Through the years the steady progress in efficiency of Led technology made today’s variety of colors possible. The color range was extended from red to orange, yellow, yellow-green, blue and white.

The relatively recent development of light emitting diodes is proving to have significant impact in lighting technology and is considered as the lighting of the future.

LED light applications

Today, LEDs are everywhere, in many shapes and forms, and cover a wide range of applications. They can be used indoors and outdoors, as practical lighting or as a design feature: in general illumination, automotive lighting, indicator lights on electronic devices, signaling, traffic lights, exit ramp lighting applications, accent lights indoor/outdoor illumination, small displays, large outdoor displays, architectural lighting decorative illumination, stairway accent lighting, concealed lighting, stage light, auditorium walkway lighting, outdoor path lights, backlight for signage letters, cove lighting, solid-state lighting, shelf lighting, outdoor glowing wall paper, ceiling illumination, recessed lighting, bar and disco lightning, amusement, under cabinet, counter lighting etc.

Curious LED’s facts

Besides the main application: lightning, some kinds of LEDs, as example the UV-LEDs, can be used for sterilization of water and disinfection of devises, and as a grow light to enhance photosynthesis in plants.

A few words about LEDs operating life...

LEDs Operating Life usually refers to the number of hours a specific type of LED is expected to be operational. With high powered LEDs that usually means, life after it loses 10-15% or more rated output after 1000 or more hours of run time. LEDs have a much longer life than conventional light bulbs and also use less power. This makes them more economical. How well LED products are able to retain their intensity when compared to new? Typically LED products will retain 70% of their intensity for 40,000 – 50,000 hours. That means a good quality LED lighting will run 8 hours a day for 13 years at 70% of their new condition. No other light source can do this. The lifetime of the new generation of LEDs is in the range of 100,000 hours of use. Could this statement be true or false? The answer is: “Yes” and “No”. Let’s see why. Advertised lifetime of a package of regular bulbs is “Life: 1000 -1120 hours” (This is defined as the time it takes for 50% of test samples to burn out). LEDs don’t burn out, after 100 000 hours of use they became completely dark because their brightness gradually fade out. Since an LED is a diode, even after it ceases to produce light, it will continue to consume power. According to the information mentioned above, the LEDs life can be expected to last on average between 50,000 – 80,000 hours before brightness begins to reduce substantially. With some calculations, if the LED operates for 8 hours every single day it will emanate light for more than 27 years.

LED’s advantages and features

As solid state light (SSL) the LED light has been described as a pivotal emerging technology that promises to alter lighting in the future. With its energy efficiencies and cost savings, LED lighting has the potential to gain a huge marketplace as well.

The LED products are highly energy efficient, long lasting and environmentally friendly. Choosing LED products for lighting solutions will not only reduce costs and save energy but it will also preserves our environment for the coming generations.

LED’s abbreviations and terminology

Cree LED – Cree LEDs are solid state LED high-brightness emitters.

Energy Efficient LED products – Energy efficient LED products are designed to consume less electricity, therefore they reduceelectricalcosts.

IP – International Protection or Ingress Protection Rating.

IP Code – International Protection Code or Ingress Protection Rating consists of two numbers and an optional letter, for example IP65. The larger each digit is, the greater the protection is. The first digit represents the level of protection against solid objects. The second digit in the IP code represents protection against liquid ingress.

LED – LED is an abbreviation for Light Emitting Diode.  The LED is a semiconductor diode that emits light when an electric current is applied in the forward direction of the device, as in the simple LED circuit. Light emitting diodes produce more light per watt than incandescent bulbs. LEDs are not bulbs or lamps in the true sense of the word and application. They need to be placed on a circuit board or other material that will allow electricity to pass through it, at a specific voltage and current, and with components required to operate them at those specific voltages, such as: 12vdc, 24vdc or 120vac. They do not come ready to plug into a 12 volt or 120 volt power sources.

LED Bar –LEDs soldered to a solid strip along with resistors and other components, that a specific product requires to make them operate at the stated operating voltage, is called LED Bar. These Bars are usually an enclosed strip of LEDs. Enclosures are plastics, aluminum, or metal composites with various types of lens/cover plates.

LED Cluster or Array – LED Clusters or Arrays are group of LEDs set in square, rectangular or linear pattern, and designed to operate at a specific voltage. They include two wires called leads, one positive, and the other negative.

LED Controller – Computer or computer-type device used to program and operate LEDs and LED devices.

LED Daisy Chain – Multiple LED products connected in series are known as LED daisy chain. For example, device A is wired to device B, device B is wired to device C, device C is wired to device D, et cetera. Device D cannot be directly connected to device A, nor are they wired back from the last device to the first.

LED Degradation – Standard method used to express the life of LED product is the time it takes to reach 50% of its day one brightness.

LED Dimming – LED dimming is a process of changing the brightness of a LED lighting through increasing or decreasing the overall LED intensity.

LED Driver – LED Driver is an electronic device used to operate LED lighting. The LED Driver functions as a current regulator that controls the brightness, the color and the intensity of the LED product. The use of LED Driver replaces the need for resistor. LED Drivers respond to the changing input voltage, while maintaining a constant amount of current (output power) to the LED as its electrical properties change with temperature.

LED Lighting – LED Lighting uses LEDs (Light Emitting Diodes) as a light source. LED Lighting is a general term and includes LED products as LED bulbs, fixtures, flashlights, strips, bars, clusters, and other LED light sources.

LED lighting system – LED lighting system uses LEDs as source of illumination and includes the following components: power source, electronic power regulator (driver) and LED.

LED low voltage transformer/adapter – LED low voltage transformer/adapter is a device that reduces high-voltage electricity (110/120, 220, 240/250V) to low voltage (12 V, 24V) so that it can be safely to run a LED lighting system.

LED power supply – The LED power supply is an electrical or electro-mechanical device. Its function is to convert 110/120/240vac line power into 12vdc.

LED Strip – LED Strips are usually printed circuit boards with LEDs soldered to the board. The strip can be rigid, or flexible and without any enclosure to protect the LED and circuit.

LM – The lumen (lm) is the SI measurement unit of luminous flux (measurement of light outputlight output), a measure of the perceived power of light. The unit indicates how much light actually falls on a surface or how much light is contained in a certain area.One lumen is equal to the amount of light emitted by one candle that falls on one square foot of surface located one foot away from one candle.

Light output indicates how much light it will generate. The unit of measure for light output is the lumen. One lumen equals the amount of light emitted by a single standard candle.

Max-Min Rated Temperature or Operating (working) Temperature of LEDs is the ambient temperature where the LED light source is installed at and should be maintained at. In most cases that is from - 20° C to + 40° C (Celsius). That is comparable from -4° F to + 104° F (Fahrenheit). Operating LED light source beyond the operating temperature will lower the LED's life span or damage it.

mA – mA is the abbreviation for milliampere. One milliampere is one thousandth of an ampere (1000mA = 1amp). The ampere is a basic unit of electric current in a circuit. Contrast with "volts," which is a measure of force, or pressure, behind the current. Multiplying amps times volts derives "watts," the total measurement of power. All LEDs run on current and the current is measured in milliamps. All LED products have a mA rating on which they are to be powered at.

MCD – Millicandela: The intensity or brightness level of an LED is measured in millicandelas (mcd). Higher the mcd number is, brighter is the light the LED emits. 1000mcd is equal to 1 candela. Candela (cd) is unit of luminous intensity and measures how much light is produced as measured at the light source. The materials used to manufacture the LED determine the brightness of the LED.

PCB – A Printed Circuit Board (PCB) is an insulated board on which interconnected circuits and components such as microchips, diodes are mounted. The circuits are formed by a thin layer of conducting material deposited, or "printed," on the surface of an insulating board. Individual electronic components are placed on the surface of the substrate and soldered to the interconnecting circuits. One or more edges of the substrate act as connectors to other PCBs or to external electrical devices such as on/off switches. A printed circuit board can be rigid or flexible.

PWM technology – Pulse Width Modulated technology of a signal or power source involves the modulation of its duty cycle, to either convey information over a communications channel or control the amount of power sent to a load.

RGB – RGB stands for Red, Green, Blue, tri-color LEDs or RGB.

Semiconductor diode – A semiconductor diode is also known as crystal diode; crystal rectifier. Today the most common diodes are made from semiconductor materials such as silicon, germanium or crystalline and consist of p-n junction or a point contact. These materials are used especially as a base component for computer chips and other electronic devices.
SI – International System of Units, System of measurement.

SMC – Surface Mounted Components are electronic components mounted directly, at only one side of the PCB (Printed Circuit Board).

SMD – Electronic devices, mounted directly onto the surface of printed circuit boards (PCBs), are called surface-mount devices or SMDs. The light, emitted from SMD LEDs, is very bright.

SMT – Surface-Mount Technology is type of method for constructing electronic components (SMC, Surface Mounted Components), which are loaded and soldered on the same side of the PCBs (printed circuit boards). In the industry this type of technology has largely replaced the through-hole technology (THT) (construction method of fitting components with wire leads into holes in the circuit board). Through-hole components (THC) have been used for many years and are designed to be loaded on one side of a printed circuit board (PCB) and soldered on the other.

SSL – SSL means Solid State Lighting. It is a type of lighting emitted from LEDs. The light is emitted from a solid object — a block of semiconductor — rather than from a vacuum or gas tube, as is the case in traditional incandescent light bulbs and fluorescent lamps, or glass neon. Unlike traditional lighting, however, SSL creates visible light without emitting heat or parasitic energy dissipation. In addition, its solid-state nature provides greater resistance to shock, vibration, and wear, thereby increasing its lifespan significantly.

7 reasons to use LED products:

• Solid state light source. Smaller, and more reliable source of light;
• Effective and efficient light source, LED products save energy (substantial savings in electrical energy consumption), have low maintenance cost and produce relatively no heat;
• Higher brightness. LEDs have higher brightness at lower cost, ideal replacement for halogen lamps;
• Long-lasting and durable. Extended life: more than 50,000 hours, they don’t burn out like regular incandescent light bulbs;
• Environmentally friendly. In contrast to glass neon, LED soft neon does not contain mercury, or other pollutants, produce no UV, and is not affected by the UV rays of the Sun;
• Attract attention. Visible even in sunlight, LEDs can produce variety of bright colors and controllable RGB effect changes using wireless remote control;
• Easy Installation.