LED LIGHTING TERMINOLOGY

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LED LIGHTING TERMINOLOGY

An LED lamp is a light-emitting diode (LED) product that is assembled into a lamp (or light bulb) for use in lighting fixtures. LED lamps have a lifespan and electrical efficiency that is several times better than incandescent lamps, and significantly better than most fluorescent lamps, with some chips able to emit more than 100 lumens per watt. The LED lamp market is projected to grow more than 12-fold over the next decade, from $2 billion in the beginning of 2014 to $25 billion in 2023, which is a compound annual growth rate (CAGR) of 25%.

Like incandescent lamps and unlike most fluorescent lamps (e.g. tubes and compact fluorescent lamp (CFL)), LED lights come to full brightness without need for a warm-up time; the life of fluorescent lighting is also reduced by frequent switching on and off. Initial cost of LED is usually higher. Degradation of LED dye and packaging materials reduces light output to some extent over time.

With research into organic LEDs (OLED) and polymer LEDs (PLED), cost per lumen and output per device have been improving rapidly according to what has been called Haitz’s law, analogous to Moore’s law for semiconductor devices.

Some LED lamps are made to be a directly compatible drop-in replacement for incandescent or fluorescent lamps. An LED lamp packaging may show the lumen output, power consumption in watts, color temperature in kelvins or description (e.g. “warm white”) and sometimes the equivalent wattage of an incandescent lamp of similar luminous output.

LEDs do not emit light in all directions, and their directional characteristics affect the design of lamps. The light output of single LEDs is less than that of incandescent and compact fluorescent lamps; in most applications multiple LEDs are used to form a lamp, although high-power versions (see below) are becoming available.

LED chips need controlled direct current (DC) electrical power; an appropriate power supply is needed. LEDs are adversely affected by high temperature, so LED lamps typically include heat dissipation elements such as heat sinks and cooling fins.

Information & images are courtesy of WikiPedia

lighting_facts

ACCENT LIGHTING
Technique that emphasizes a particular object or draws attention to a particular area.
Accent Lighting usually utilizes a tight beam angle PAR, MR or GU light source.
ALTERNATING CURRENT (AC)
Electrical current in which the flow of electric charge continually reverses direction.
AMBIENT
The surrounding light level in a given area. It is also the temperature in which a LED light source is expected to operate in. Referring to light, it is the light given off by the Sun, Moon, other light fixtures nearby or even within the same space.
AMBIENT LIGHTING
Lighting designed to provide uniform light levels throughout and area.
BACKLIGHTING
Use of light source to illuminate from behind without protrusion through the panel.
BALLAST
The device that limits amount of current in an electrical circuit.
BEAM ANGLE
Size of the cone of light produced by lighting source measured in degrees.
BULB BASE
The part of the bulb that is used to set it into place and to make contact with electricity. There are many types and sizes. Most common are E26/27, USA and European standard household size, or medium base as it often is called. The 26 or 27 equates to the diameter measurement in millimeters of the threads of a screw-in bulb base. This type of bulb also includes the PAR 20, PAR 30 and PAR38 types, and a few others. There are MR16 and MR11 type base LED bulbs as well as GU10s. There are also E12 candelabra base led light bulbs.
CAN LIGHT
Short for Canister Light. Another name for a recessed light or down light which is a fixture installed into a hollow opening in a ceiling.
CE
Certifies product has met EU (European) consumer safety, health and or environmental requirements.
CFL
Compact Fluorescent which consume less energy than Incandescent with the negative aspect of Mercury/Poison content.
CORRELATED COLOR TEMPERATURE (CCT)
This is a measurement of the Yellowness or Blueness of a White light source based on a Kelvin number. Yellowish White described as Warm White is comparable to Incandescent Lamps which have a lower Kelvin temperature number around 2700-3000 range. White and Bluish White described as Natural White and Cold White have a higher Kelvin Temperature of 5000-7000.
COOL WHITE
Kelvin color temperature of 5500-7000
COLOR RENDERING INDEX (CRI)
Color Rendering international system to rate lighting device ability to render object colors. The higher the CRI (based on a 0-100 scale), the greater the color fidelity of the lighting source. Natural outdoor light has a CRI of 100.
DIE-CAST
A term that refers to the process of forcing molten metal, under great pressure, into a die or form to give it a specific shape. A very efficient process, excess material can be reused for future casting.
DIFFUSER
Optical element used to mix light ray to improve uniformity of light.
DIMMER
12vdc only. Used with LED lights powered by 12vdc – never 110/120vac. PWM built-in, as is an On/Off Switch. Will dim majority of 12vdc LED lights and a few 12vdc LED bulbs such as MR16s with the proper transformer/power supply. Dimmers are part of our LED control products.
DIODE
Semi-conductors similar to a computer chip that emit light when electricity is applied to them.
DIRECT CURRENT (DC)
Electrical current which the flow of electric charge moves in one direction only.
DOWN LIGHT
Light source set in a metal cylinder. Mounted or recessed into the ceiling so the beam of light is directed downward.
DRIVER
Auxiliary device(s) needed to operate and vary the intensity of light output from LED lamp source(s) by regulating the voltage and current powering the source.LED power supply providing either a constant level of current or a constant level of voltage.
DRIVER RATING
Parameters that define the operating power level output. The rating also includes both input and output specifications (voltage, current, frequency, etc.).
E26/E27
Edison Screw fitting system designated at standard screw-in bulb bases. Also referred to as a “Medium” or “Standard” Base. E26 Base is U.S. standard. E27 is European standard. The number after the E refers to the number of millimeters of the base.
ENERGY STAR
A United States government program created in 1992 by the US Environmental Protection Agency in an attempt to reduce energy consumption and green house gases. What began as a voluntary labeling program has grown into one of the largest efforts worldwide to promote energy efficient consumer products with ES certifications.
ETL
Originally a mark of ETL Testing Laboratories, now a mark of Intertek Testing Services.
FLICKER
Noticeably unstable light output, usually involving large, quick changes in light intensity.
FLOOD LIGHT
A lamp that provides a broad beam intended to light a general area.
FLUORESCENT TUBE
Light source consisting of a glass tube filled with low pressure mercury vapor. Electrical discharge through the vapor produces ultraviolet light that excites phosphor materials on the inside of the tube which emit visible light.
FLUX
Sum of Lumens emitted by a light source.
FOOT-CANDLE (FC)
Unit of light falling onto a surface. One foot-candle is the light level on a surface one foot from a standard candle.
GU
A bipin base code. Each Pin has two diameters. Being larger near the ends in order to twist and lock into position in the socket. GU10 Being one of the most common base products almost always 110/120V AC.
HEAT DISSIPATION
This is the transition of thermal energy form a hotter object to a cooler object. With LED heat sinks made from high quality aluminum and other alloys accomplish this.
HEAT SINK
A device or substance used for absorbing and dissipating excessive or unwanted heat.
HIGH INTENSITY DISCHARGE (HID)
Electrical lamp filled with gases and other compounds in which an electric arc is passed between tungsten electrodes to produce light.
HIGH PRESSURE SODIUM (HPS)
High Intensity discharge lamp offering a warm Correlated Color Temperature (CCT) high levels of efficiency, long life with very modest levels of CRI.
INCANDESCENT LIGHTING
Light produced when a filament is heated to incandescence using electrical current. Incandescent lighting is very inefficient since most of the energy is wasted as heat rather than light.
KELVIN (K)
Unit of temperature starting from absolute zero.
KELVIN TEMPERATURE
Color measure as to Yellowness or Blueness of the color white. The higher the Kelvin temperature the more Blue than White.
KILOWATT (KW)
Measure of electrical power equal to 1000 Watts.
LED
Light Emitting Diode solid state semiconductor device that converts electrical energy directly into light. LEDs are a solid state device and do not require heating of a filament to create light. Rather, electricity is passed through a chemical compound that is excited and that generates light. LEDs are not bulbs or lamps in the true sense of the word and application. LEDs require a lot of work to make them ready to be used by the consumer. 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 specific voltages such as 12vdc, 24vdc or 120vac. They do not come ready to plug into a 12volt or 120 volt power source.
LED array (also called an LED light engine)
A device that incorporates LEDs into a package that may then be integrated into a fixture. It typically integrates multiple LEDs onto a PCB (printed circuit board) and may be replaceable.
LM-79
IESNA approved method for the electrical and photometric test of solid state lighting devices. Specifies procedures for measuring total luminous flux electrical power, luminous efficacy.
LM-80
IESNA approved method of measuring Lumen depreciation of LED Light sources. It is related to the effective useful life of the product.
LUMEN
Measurement of luminous flux of quantity of light emitted by a source. Specifically, lumens measure the amount of light an electric source (lamp) produces in all (360 degrees) directions (e.g. a candle gives off ~12 lumens, while a 100 W A19 incandescent lamp gives off ~1,650 lumens and a 4 ft 32 W T8 fluorescent lamp gives off ~3,100 lumens). Higher the Lumen, the Brighter the Light.
LUMEN MAINTENANCE
Describes how long a light source will retain a certain percentage of its initial Lumen output.
LUMINARIES
Lighting fixture complete with lamp, housing, power supply and optical components used to direct light.
LUMINOUS EFFICACY
Measurement of how effective the light source is in converting electrical energy to Lumens of visible light. Usually expressed in Lumens per watt (LPW)
LUX
Unit of luminance or density of light falling onto a surface. One lux is equal to one lumen per square meter.
METAL HALIDE (MH)
High Intensity light source produced by the radiation from mercury, plus halides of metals such as sodium, scandium, indium, and symposium.
Mp
Stands for milliamp. 1000Ma equals 1.0 amp. All LEDs run on current and current is measured in milliamps. All LED products have a Ma rating at which they are to be powered at.
MR
A bipin base code for a 2 sharp pin push in base. Almost always 12V Product. The MR16 LED lamps are a very popular replacement for Halogen.
NATURAL WHITE
Light with a Kelvin Temperature between 4500 and 5500.
OPTICAL PERFORMANCE
Optical performance is measured by photometric data covering the efficiency, output, quality and life of a light source.
PAR LAMP
Acronym for a Parabolic Reflector. PAR20, PAR30, PAR38 are Most Common.
PCB
Printed Circuit Board are made from various materials including fiberglass and aluminum. The PCB has an electrical circuit imprinted in silver etching. That circuit says how the LED will operate. The PCB is also the platform by which LEDs are employed in various applications. It can be a rigid board or flexible to twistable.
PHOTOMETRIC
Measurement of light intensity. Photometric parameters including lumens, intensity, luminance, illuminance, CRI etc.
POWER SUPPLY
Device that supplies electricity for energy. Most LED Power Supplies Convert Line Voltage (110AC) to 12 & 24V DC.
RGB
Acronym for Red, Green, and Blue. These are the 3 primary colors of light. Combinations of these 3 colors to create wide variety of other colors.
RoHs COMPLIANCE
LEDs that are soldered to the surface of the circuit board. The LED Die is integrated into the package design. Surface Mounted LEDs can be assembled faster and with better quality than Dip through-Hole Components.
SMPS
A switched-mode power supply (switching-mode power supply, SMPS, or switcher) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently.
SOLID STATE LIGHTING
A type of lighting that uses semi-conductor light emitting diodes (LEDs) or organic light emitting diodes (OLED) as sources of illumination rather than incandescent, plasma or gas lamp sources.
SPOTLIGHT
A lamp that produces a narrow beam angle designed to illuminate a specific targeted area.
TUBE LIGHT
Term used to describe a fluorescent tube. Most typical sizes are T5, T8, T10 and T12. T indicates the shape of the bulb is tubular.
Typical diameters T5 =5/8 " T8 =1" T12=1 1/2" Traditionally the T8, T10, and T12 use the dual pin G13 Socket.
UL LISTED
A product adhering to the standards of Underwriters Laboratories, a company nationally recognized for product safety testing (the product is not "approved" nor tested for performance). Underwriters Laboratories was initially created by insurance companies to reduce fire risks. In Canada, CSA is the listing required.
ULTRAVIOLET (UV)
Invisible radiation that is shorter in wavelength and higher in frequency than visible violet light. UV rays are light waves that are similar to the light from the sun. UV radiation can cause oxidation, fading of colors of furniture, carpet, draperies and art work.
VOLTAGE
The rate at which energy is drawn from a source that produces a flow of electricity (amperage) in a circuit. The difference in electrical charge between two points in a circuit is expressed as volts.
WARM WHITE
White color with a Kelvin temperature between 2800-3200.
WATTAGE
The unit for measuring electrical power. It defines the rate of energy consumption by an electrical device when it is in operation. The energy cost of operating an electrical device is calculated as its wattage times the hours of use. In single phase circuits, it is related to volts and amps by the formula: Volts x Amps x Power Factor = Watts.
WAVELENGTH
Distance between two points of corresponding phase and is equal to waveform velocity divided by frequency.
WEATHERPROOF
Weatherproof meaning the product will take water splashing and high humidity without deterioration to the LED or circuit. LED product cannot be submerged into water.