The special energy that can be propagated in the form of waves and forms the visible part of the electromagnetic spectrum, can be perceived by the human eye and forms the part between 380 nm and 780 nm wavelength is called "Light". This special energy propagates in the form of waves or photons and is known as the fastest matter in the universe.
Luminous intensity is generally defined as the light intensity per unit of time emitted in a certain direction at a certain time. This light intensity is defined for point light sources and grows depending on the direction of the light. The symbol of this term is "I" and its unit is "Candela".
The amount of light emitted by a light source in unit timeis also known as “Lm” and its unit is “Lumen”. This luminous flux, also known as energy flux, is evaluated according to the spectral sensitivity curve of the eye’s daytime vision, coming from the light source.
It is the unit of average illuminance level. This unit is the ratio of the vertical component of the light flux falling on the surface to the surface. This ratio is shown as lx and its unit is lm/m2 = lux.
There are many differences in lighting levels between illuminated areas. For example; The brightness level of the work area should be different from the lighting levels in other areas. Otherwise, distraction may occur.
It is the effect of a bright light source on the human eye. This effect makes it difficult to see objects and the work area in the environment. In order to avoid the glare problem, instead of a high-power product, several different products should be used in the area to be illuminated. In this way, the glare problem is eliminated.
The value obtained by dividing the luminous flux emitted by the light source by the power it consumes is called luminous efficiency.This value is also called “efficiency factor”. It is expressed by “η” and its unit is lumen/watt (lm/w).
The efficiency factor, which means the same as luminous efficiency, is the ratio of the luminous flux coming from a particular light source or luminaire to the total power of its source. In short, it is the luminous flux value that the light source or luminaire reflects in response to the 1W power it draws from the network.
Luminance is generally a concept related to light intensity, depending on any point and direction of the surface. This concept is indicated by the letter "L" and its unit is cd/m2. Luminance can be a lighting system or fixture that produces light, or it can be a secondary light source that reflects light from another lighting system.
It expresses the ratio of reflected light. The higher this ratio is, the brighter and smoother the surface is. This ratio is expressed with "ρ".
It is the name given to the lights that lighting systems generally produce. These lights are generally divided into three groups: luminescent, electroluminescent and thermal.
It is the ratio of the luminous flux coming from the luminaire to the total luminous flux inside the luminaire.
Thermal light production is the state of solids or liquids when they pass to high temperatures. For example; Incandescent (glow wire) lamps produce light according to this principle. The light spectrum they produce is continuous.
When molecules pass from the excited state to the ground state, they give back the energy they receive. In this case, it occurs when the 2 solid electrodes become conductive and the electron flow excites the gas atoms. If these electrons are large enough, radiation occurs. For this reason, they emit light at certain wavelengths according to the type of gas and their partial pressure. Thus, lamps that work according to the production of luminescent light are called high-pressure or low-pressure due to the pressure of the gas inside.
It refers to the resistance of all lighting fixtures against dust, water, solid objects and moisture. This resistance term is shown with the code IPX1X2, according to international acceptance. In this code, (X1) represents resistance against solid objects and (X2) represents resistance against water.
It is the name given to the type of lighting fixture whose maximum light intensity is limited to an angle of 65° in the vertical area. Such lighting fixtures do not emit any light to the upper half space.
It is a type of lighting fixture whose maximum light level is limited to an angle of 75° in the vertical area. Semi-screened lighting fixtures do not send more than 10% of the light flux to the upper half space.
It is a type of lighting fixture whose maximum light level is not limited to a certain angle. This type of lighting fixture reflects light intensity at a 90° angle in the vertical. In addition, regardless of the screenless fixtures, the light flux of the lamp does not exceed 1000 cd.
Electroluminescence is generally based on the conversion of electrical energy into light energy. This light production is light sources that have unidirectional movement of electronsand emit light when an electric current passes through them.Thus, LED chips, which are formed by the combination of a P-type semiconductor with an N-type semiconductor, pass from the negative side to the positive side and combine with holes and emit photons. LED Lighting, which has increased its efficiency especially after 1999 They stand out with their high efficiency, high quality color features and long life. The most common LED chips are;
Electroluminescence is generally based on the conversion of electrical energy into light energy. This light production is light sources that have unidirectional movement of electronsand emit light when an electric current passes through them.Thus, LED chips, which are formed by the combination of a P-type semiconductor with an N-type semiconductor, pass from the negative side to the positive side and combine with holes and emit photons. LED Lighting, which has increased its efficiency especially after 1999,LEDs are basically obtained in 2 ways. These are;
If a luminaire design is to be made with LEDs, optical designs, thermal and electrical current should be taken into consideration. Especially for high power LEDs.e, a little light comes out. Therefore Mixing problems that may occur can be prevented with good optics. When we consider the rate of converting electrical energy into light energy of LEDs, we can observe that it varies between 20-40%. However, the remaining 60-90% is converted into heat. Accordingly, the thermal design is well done. In LED fixture, heat accumulates and light is produced at the junction point temperature increases. In addition, the LED junction temperature the increase is, It reduces the luminous efficiency of the LED and reduces the efficacy factor value, which indicates the amount of luminous flux obtained per unit power. LED chips generally work with direct current. For this reason, they need to have a power supply to receive energy from the network. with driver They are used. The second driver they use is benefit is to create the nominal current required by the LED. Thus, The efficiency rates of LED drivers are decreasing.Lamps stand out with their high efficiency, quality color features and long life. The most common LED chips are:;
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