Alternating current (AC) Electrical current whose movement periodically reverses direction.
Ampere Unit of measure of the rate of electrical current flow.
Ballast Any electrical component used to reduce the current in an electrical circuit.
Candela The luminous intensity of a light source that emits monochromatic rays in a particular direction. It measures the brilliance of a light source as perceived by the human eye.
Colour Rendering Index (CRI) The capacity of a light source to reconstitute the different colours in the visible spectrum without changing the shade of colour. The general colour rendering index “Ra” determines the quality of light from a rendering index of 8 standard colours. The maximum index, Ra=100, corresponds to white light with the same spectrum as sunlight.
Colour temperature Determines the (actual or “virtual”) temperature of a light source from its colour. Colour temperature is measured in Kelvins (K).
Compact fluorescent Fluorescent light, or the compact fluorescent bulb (CFB), is an adaptation of the industrial fluorescent tube for household use. It’s a miniature light-emitting tube folded in two, three or four, or rolled up, with a rounded base containing electrical ballast.
Contrast The manner in which light is distributed throughout an image or between two specific points in an image (“pixels” in digital photography).
Diode A specialized electronic element that allows current to pass through in a single direction
Direct current (DC) Electrical current that does not change direction and keeps a constant intensity.
Electricity A form of energy resulting from the flow of charged particles (electrons, ions) through a conductor.
Energy A stored or usable entity (a force) that can carry out work.
Halogen Any of the chemical elements in the chlorine family whose silver salts are photosensitive.
Incandescence A universal physical phenomenon in which light is produced from heat.
Ion An atom with an electrical charge.
LED A diode that emits visible light when electrons and holes are recombined as the current passes through a junction.
Light Periodic electromagnetic wave with an extremely short width, producing a chemical and thermal effect, and generally perceived by the eye.
Lumen A unit of measure of energy efficiency. A lumen is a subjective unit that depends on perception by a human being. It quantifies the amount of light perceived by the “average person” in the presence of a source of electromagnetic radiation.
Luminance Luminous intensity radiating from a light source in a particular direction, per unit area of the source in the same direction.
Lux The unit measuring luminance. It quantifies the light flow received per unit surface area.
Power The watt is the unit measuring power, energy flow and thermal flow.
1 watt = 1 joule per second
1 kilowatt (KW) = 1000 W
1 megawatt (MW) = 1000 KW
Renewable energy (REN) Energy flow produced by different natural processes (solar radiation, wind, plants, waterfalls, etc.) Contrary to fossil fuels, renewable energy cannot be depleted and does not produce greenhouse gas emissions.
Resistance A material’s opposition to the flow of electrical current. It is measured by the quotient of the tension divided by the current passing through.
Transformer A device that transforms one form of energy into another.
Ultraviolets Electromagnetic radiation (UV) of an intermediate wavelength between visible light and X-rays.
Volt The unit of measure of tension.
Watt The unit of measure of the quantity of energy produced. (Watt = ampere x volt).