Common Terms In The LED Industry
Ambient Light:It is the combination of light reflections from various surfaces to produce a uniform illumination called the ambient light.
Ampere: (symbol: A)
The SI unit of electric current. the basic unit of electric current adopted under the Systeme International d'Unites; "a typical household circuit carries 15 to 50 amps.” In practical terms, the ampere is a measure of the amount of electric charge passing a point in an electric circuit per unit time.
Beam Angle:
The angle at which the light is distributed from it’s source.
Chromaticity: Color Temperature Current Regulator: DIALux: Efficacy: Foot-Candle: Full-spectrum light IP Rating Colour temperature L.E.D.: LED Drivers: Lifetime: (LED) Light Meter Lumen Maintenance: Lumens: Luminaire Lux: NEMA Operating Life: Operating Temperature: Optics: Photometry: Power Supply: Prescription A unique and exlusive Optilume-coined term Solid-state lighting (SSL) Voltage: Voltage Regulator: Volts: Watts Source: http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License
The aspect of color that includes consideration of its dominant wavelength and purity.
The color rendering index (CRI) (sometimes called color rendition index), is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications such as photography and cinematography.
Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that of the light source. Color temperature is conventionally stated in the unit of absolute temperature, the kelvin, having the unit symbol K. Color temperatures over 5,000K are called cool colors (blueish white), while lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red).
The Canadian Standards Association, also known as the CSA, is a not-for-profit Standards organization. CSA is a provider of print and electronic standards, related training and elearning, as well as Advisory Services. Their registered mark shows that a product has been independently tested and certified to meet recognized standards for safety or performance.
A current source is an electrical or electronic device that delivers or absorbs electric current to maintain a constant current to a load. A current source is the dual of a voltage source.
DIALux is a lighting design software. It is available free of charge and can be used to work with the luminaires of any luminaire manufacturer. DIALux is the most efficient lighting calculation software to be found on the market. It covers all the requirements of modern lighting design and lighting calculation. So that this remains so, DIALux is continually being developed.
Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power. Depending on context, the power can be either the radiant flux of the source's output, or it can be the total electric power consumed by the source. Which sense of the term is intended must usually be inferred from the context, and is sometimes unclear. The former sense is sometimes called luminous efficacy of radiation, and the latter luminous efficacy of a source.
The unit is defined as the amount of illumination the inside surface of a 1-foot radius sphere would be receiving if there were a uniform point source of one candela in the exact center of the sphere. Alternatively, it can be defined as the illuminance on a 1-square foot surface of which there is a uniformly distributed flux of one lumen. This can be thought of as the amount of light that actually falls on a given surface. The foot-candle is equal to one lumen per square foot.
The SI derived unit of illuminance is the lux. One footcandle is equal to approximately 10.764 lux, although in the lighting industry, typically this is approximated as 1 footcandle being equal to 10 lux.
Light that covers the electromagnetic spectrum from infrared through near-ultraviolet, or all wavelengths that are useful to plant or animal life; in particular, sunlight is considered full spectrum, even though the solar spectral distribution reaching Earth changes with time of day, latitude, and atmospheric conditions.Intensity:
The IP Code (or Ingress Protection Rating[1], sometimes also interpreted as International Protection Rating[2]) consists of the letters IP followed by two digits or one digit and one letter and an optional letter.
A characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The colour temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that of the light source. Colour temperature is conventionally stated in the unit of absolute temperature, the kelvin, having the unit symbol K.
Colour temperatures over 5,000K are called cool colors (blueish white), while lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red).
Light-emitting diode, a semiconductor diode that glows when a voltage is applied
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.
The lifetime in hours expressed as the point in time in which the lumen output of an LED has degraded by 30%, leaving 70% of initial lumen still available.
Example: L70 for a particular LED had reached 70% of its initial lumens at 50,000 hours.
A light meter is a device used to measure the amount of light.
A measure of the level of lumen output produced by a lamp or luminaire over time compared to the initial level of lumen output.
The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power (radiant flux) in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all light emitted, independent of the eye's ability to perceive it.
The lumen is defined in relation to the candela as 1 lm = 1 cd·sr
A light fixture, light fitting, or luminaire is an electrical device used to create artificial light and/or illumination. All light fixtures have a fixture body, the direct device that produces the light, it may also have a switch to operate the fixture, and also require an electrical connection to a power source, often by using electrical connectors (e.g. plugs) with portable fixtures. Light fixtures may also have other features, such as reflectors for directing the light, an aperture (with or without a lens), an outer shell or housing for lamp alignment and protection, and an electrical ballast and/or power supply.
Typically used to measure the light intensity produced by a lighting fixture. The higher the lux reading the more light the lighting fixture is producing over a given area. Known as lumens per square meter.
Is a measure of the time-averaged energy flux or amount of light striking a given area. For bulbs alone this is measured in terms of lumens while for lighting fixtures it is measured in lux (lumens/sq. meter).
NEMA stands for National Electrical Manufacturer Association. Their website is at www.nema.org. NEMA ratings are standards that are useful in defining the types of environments in which an electrical enclosure can be used. The NEMA rating system is defined by the National Electrical Manufacturer Association, and frequently signifies a fixed enclosure's ability to withstand certain environmental conditions.
In the LED industry, it is 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. The Cree and Luxeon LEDs are rated for 50,000 at 75% maintenance for 50,000 hours.
An operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the maximum operating temperature (or peak operating temperature).
Primary Optics are the optics that form part of the LED and serve to protect and to shape the light output of the diode.
Secondary optics are optical elements used in addition to the LED’s primary optic to shape the LED’s light output’s intended distribution pattern.
The measurement of the properties of light, especially luminous intensity.
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, such as AC to DC voltage). A regulated power supply is one that controls the output voltage or current to a specific value; the controlled value is held nearly constant despite variations in either load current or the voltage supplied by the power supply's energy source.
In the LED industry, a power supply typically converts 110/120/240/347VAC line power into in a lower DC voltage that will then be applied directly to the LED light product.
A prescription is the name given to the unique combination of direction, pitch and reflector angle for each LED unit in Optilume's luminaires. Each fixture is given it's own prescription based on the requirements of the clients application in the same manner that a unique prescription is given by an optometrist for a pair of eye glasses.
Solid-state lighting refers to a type of lighting that uses semiconductor light-emitting diodes (LEDs)current passing through a chemical that will get excited and thus emit light.
When a light-emitting diode is forward biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor.
Otherwise known as electrical potential difference or electric tension (denoted ∆V and measured in volts, or joules per coulomb) is the difference in electric potential between two points -- or the difference in electric potential energy per unit charge between two points.
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.
The volt is defined as the value of the potential difference (voltage) across a conductor when a current of one ampere dissipates one watt of power in the conductor.[2] It is also equal to the potential difference between two points 1 meter apart in an electric field of 1 newton per meter.
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 PowerFactor = Watts.