An LED is a semiconductor element that converts electrical current into light radiation. The principle of operation of an LED is based on luminescence. The LED has two terminals – plus and minus. The Plus is fed to the anode, and the minus to the cathode. Therefore, the polarity must be observed when connecting the LEDs.
LED stands for Light-emitting-diode. It consists of a semiconductor crystal mounted on a copper and aluminum substrate, along with contact leads and an optical system.
The light color is determined by the wavelength of light emitted by the LED crystal and depends on the chemical composition of the semiconductor. Currently, LEDs are produced in the visible, ultraviolet and infrared ranges.
There are several types of LEDs:
- DIP – LEDs are the first mass-produced LEDs. The crystal is installed in a housing with a lens. They have two contacts. Mainly used in light displays.
- Piranha or Superflux LEDs have a similar design, but not two, but four leads.
- SMD – LEDs (surface mounted device) are manufactured using surface mounted technology (TMP). The chip is mounted on the board surface through a ceramic substrate, which provides a small size and good heat dissipation. SMD – LEDs are the most common.
- COB – technology (Chip-On-Board) – a chip of a crystal or several crystals are mounted on a board without a ceramic substrate and covered with a layer of phosphor, which provides high reliability, compactness and heat dissipation.
Application over the crystal of the phosphor allows you to get any glow of the LED. A phosphor LED absorbs the non-visible spectrum of light to convert them and emit a visible spectrum of light which is markable by a bare human eye.
A phosphor is a substance that has luminescence – the ability to convert absorbed energy into light radiation. The term “phosphor” comes from the Latin lumen – light and the Greek phoros – carrier. The high efficiency phosphor provides different ranges of color lighting to the LED. The evolving technologies of phosphor in LEDs have increased the supply, demand, light efficiency and business opportunities with an overall LED market growth.
The following phosphors are common in LED production: yttrium-aluminum garnet (YAG) doped with trivalent cerium, and alkaline earth metal silicates doped with europium. For example, a blue LED covered with a yellow phosphor will glow white.
The main advantages of LEDs:
- high lighting performance. They can produce different color lighting effects without bringing much changes in their components
- low heat emission. They have heavy-duty heat sinks;
- no harmful radiations;
- low power consumption and high energy efficient. Most of the electric energy is converted into light energy because of their high lumen and less conversion to heat energy;
- long service life. They do not have filaments to melt and burn like traditional bulbs; instead they have lumen depreciation over time. This also makes them safer to use.
- compactness and ease of installation;
- wide temperature range of application;
- mechanical strength;
- environmental friendliness;
- Availability and price.
The applications of LEDs:
- LED signals and indicators – They are used in small to large signaling instruments like traffic signals, directional signages, and entry and exit signs. They are also used on keypads of your laptop and TV remotes. They are also used as indicators in light to heavy vehicles due to their long lifespan and high intensity that makes them visible clearly even on a foggy night.
- LED lighting appliances – They are used for lighting purposes in residential, commercial and healthcare services. It is due to their durability, energy efficiency and no harmful radiations.
Due to their advantages, LEDs are widely used in various fields: in outdoor and indoor advertising (boxes, letters, LED boards, “Creeping lines”, video screens, unique lighting effects and design solutions), in architectural lighting, in household, office and industrial lighting , landscape lighting, window lighting, interior lighting, festive illumination, in the production of LED screens for monitors and televisions, in instrument making as indicators, in road signs, decorative lighting, in light and New Year decorations.
As mentioned above, LEDs offer many advantages in terms of cost, lighting and efficiency. Choosing to use LEDs would be a wise and economical choice. In addition to being efficient in use, LEDs are very easy to find in case of purchase. In addition, they are also suitable for industrial use as mentioned above. For more LED information, visit https://www.ledlightexpert.com/LED-Learning-Center_ep_42-1.html