Bright LEDs: design and principle of operation, where they are used, types of superbright lamps

Thanks to modern technologies, there has been a major modernization of lighting fixtures in recent years. The usual incandescent lamps have been replaced by more economical and durable ones. A special stage is the emergence of high-brightness LED lamps. Bright LEDs have found applications in various fields.

Varieties of lamps

Today the range of lamps for lighting is presented in various models from standard to ultra-modern. They all have different characteristics:

• Incandescent lamps. For a long time, they were the only light sources, had a power of 15 to 300 watts. Modern lamps are divided into two types. In krypton, the inert gas krypton is used, which provides good light output. Their minimum power is 40 W, the maximum is 100 W. Bispiral models function due to an arcuate tungsten filament, can have a mirror, transparent or opal surface.
• Luminescent. They emit light thanks to the phosphor coating, which is exposed to the ultraviolet rays of the gas discharge. Provide soft diffused light of different power (from 8 to 80 W). They give 7-8 times more luminous flux than incandescent lamps, last 10-20 times longer. They are distinguished by flickering light and sensitivity to temperature extremes.
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• Halogen. Available in different shapes and sizes. The light emitted by them can be scattered or in the form of concentrated beams. Due to the ability to shine in very bright saturated colors, halogen lamps are widely used in a modern design to create original lighting solutions in residential and outdoor spaces. Halogen lamps have a variety of installation options. They can be hung at the top or on the walls, embedded in the suspended ceiling in the form of point fixtures, or fixed to furniture. The swivel models have a special rotating holder that allows you to direct the light beams in the desired direction.

Among the entire range of lighting lamps, LEDs stand out for the lowest energy consumption, therefore they are very popular among consumers. They are characterized by high brightness, light transmission of the order of 60 - 80 lm / W. The service life of devices with a power from 7 to 21 W / h can reach 100 thousand hours.

A separate type of LEDs are stand-alone lamps powered by rechargeable and solar batteries. Such lamps are effective both at high (+50) and low (-30) temperatures. They tend to turn on independently with the onset of darkness, therefore they are successfully used for street lighting.

LED construction

The LED luminaire has a rather complex structure. Its design includes several elements, each of which performs a specific function:

• LED chips. They act as the main parts that provide the glow. Depending on the size of the luminaire and the desired power, it can contain from one to several dozen interconnected chips. If one of them breaks down, the others also stop working. The characteristics of the lamp and its service life depend on the quality of the chips.
• Printed circuit board. It is made of aluminum alloys that dissipate heat well and provide the temperature necessary for the functioning of the chips.
• Radiator. It dissipates heat from the printed circuit board with chips. They are made of aluminum alloys and molds with many individual plates. With the help of these plates, the heat dissipation area of ​​the radiator is increased.
• Driver. Smoothes, reduces and stabilizes the voltage at the input of the electrical circuit. It can be remote or built-in. The second type is used more often.
• Capacitor. Eliminates the ripple voltage that comes from the driver to the LED crystals.
• Base / plinth. Serves for connecting cartridges. Nickel plated brass is used for its production. These materials provide good bonding and long-term corrosion protection.
• Polymer base. Fitting tightly to the base, it guarantees protection of the case against electrical breakdowns. Also, the base protects users from electrical injuries when replacing bulbs.
• Diffuser. It has the shape of a hemisphere, made of frosted polycarbonate or transparent plastic, which eliminates the risk of damage if dropped. Designed to increase the angle of uniform scattering of the light beam. Practically does not heat up when the lamp is on.

The peculiarity of LEDs is the location of the area of ​​maximum heating. If in other types of lighting lamps, thermal energy is distributed from the outside of the surface, then in diode lamps the printed circuit board heats up from the inside. Therefore, regular heat dissipation from the lamp is necessary to ensure efficient and safe operation.

Types and characteristics

With the development of technologies based on conventional LED bulbs, the production of semiconductor devices, characterized by a very high luminous intensity, began. Superbright LEDs have a specific classification.

The lamps of the Taiwanese manufacturer Epistar are characterized by compact dimensions and high quality indicators. They have a very long service life.

Smd brand products have several series (3528,3014, 3020, 2835, etc.) R.). The most demanded are bright LEDs of the SMD 5050 series, characterized by a powerful white glow (power reaches 1 W). Often used in conjunction with special power supplies that reduce the operating voltage to 12 V.

XLamp's lineup consists of three ultra-bright LEDs - XR, XP and MC. Each is individually sized and shaped, but all use a large operating current in excess of 350mA and have a highly efficient heat dissipation system. They are used for indoor and outdoor lighting of modern cars.

One of the striking examples of high-power LEDs is the lamps of the American company Cree. It produces lighting fixtures in different housings:

• With STD leads (374, 512, 503, 4SM, 5SM, etc.) R.). Standard enclosures have a circular cross-section of 3 and 5 mm and an oval cross-section of 4 and 5 mm.
• In the "Piranha" housing of the P4 type (series P41, P42, P43).
• In a PLCC type package (LM1, LM3, LM4, LP6, LN6, LA1 series, etc.) ). Suitable for surface mounting.

Regardless of the type, superbright LEDs operate according to the same principle of a directed electron flow from the p-anode to the n-cathode. To form a junction, the LED chips inside the lamp are coated with dopants. The shade and wavelength of the luminous flux in each high-brightness lamp are determined by the width of the working p-n zone.

The quality of the diodes is determined by the brightness of the luminous flux and the angle of dispersion. Depending on the temperature, the glow can be orange, amber, green, blue, red or white. White light is divided into cold (5000 - 7000K) and warm (2700-3500K).

The scattering angle also varies from 15 to 120 degrees. Due to bulbs with different scattering angles, original lighting solutions are created with highlighting of different zones.

Installation features

Before installing an ultra-bright LED, you should pay attention to what current characteristics it has. The main quantity is its constant operating current. The average for most ultra-bright devices is in the 15-20 mA range. The maximum values ​​of ultrabright lamps are up to 1 A.

The next important indicator - operating voltage - depends on the shade of the emitted light. Infrared color is characterized by a minimum value from 1.5 to 1.9 V, for white - a maximum value, reaching 3.7 V. One driver with a constant output voltage of 12 V can be connected to 4 bright diodes with a voltage of 3 V or 12 diodes of 1 V each. A driver with an output voltage of 12 V should be connected to a 220 V.

The main condition for installing any diode lamp is the observance of the polarity of the power supply. Since luminaires with high brightness heat up the light crystals strongly, an efficient cooling system must be provided. In most super-bright models, it is implemented using heat sinks. If such radiators are not provided by the manufacturer, you need to take care of the cooling yourself. During the installation process, it is necessary to provide high-quality electrical insulation.

A properly installed LED lamp can work for at least 50 thousand hours. At the same time, its use will be economically profitable and will not harm the environment due to the absence of gas vapors, mercury and other hazardous components. Bright LEDs are characterized by such qualities as immunity to voltage and temperature surges, vibration resistance and shock resistance. Compact lamps are capable of withstanding a large number of starts.

All the advantages that superbright diodes have are reflected in their cost. Their price is quite high, but their long service life and high-quality characteristics make it possible to achieve a payback of the devices.

Each LED luminaire has its own characteristics. Therefore, with the help of several diode lamps, it is difficult to achieve uniform illumination (even if they are made by the same manufacturer and belong to the same series). The declared color rendition also does not always correspond to the real one. Not all lighting fixtures are equipped with dimmers.

Application area

High technical and operational indicators allow widespread use of super-bright LEDs. The most common applications are:

• Mobile devices. They play the role of a backlight in both single-color and multi-color displays operating on liquid crystals.
• Road signs. They are used in traffic lights, street signs, since they do not require frequent maintenance after installation.
• Illuminated advertising. Used to illuminate volumetric letters, light boxes, advertising signs and ultra-thin light boxes. White light emitted by diodes is a more efficient alternative to the previously used neon.
• Alphanumeric scoreboards. Direct light serves as a tool for conveying information on single-color boards and full-color video displays in shopping malls and sports stadiums.
• Transport. Due to their small size and ultra-high brightness, they ensure the operation of external signaling devices (turn indicators, brake lights) and dashboards installed in the interiors of vehicles (cars, buses, motorcycles, aircraft).
• Architecture and landscape. They show high efficiency when illuminating building facades and various landscape compositions.

High brightness diodes are used not only in general use, but also in everyday life. For example, they are increasingly replacing traditional lighting when installing stretch ceilings.