Sample:

Created by: Linva

Elintech International electronics Limited

Attn: Linva

Tel: 0086 755 61672078

Fax：0086 755 33902139

Mobile: 0086-13510577072

E-mail:Linva07072008@hotmail.com

1. LED Electronic Display System is a multimedia hi-tech product that blended optical, electronic and acoustic signal processing technologies. It includes the followings devices:
☆ Display screen
☆ Control computer and communication system
☆ Computer and its related peripheral
☆ Video peripheral
☆ System software
2. System Features:
☆ Available for connection to an external scanner, and accepting various pictures, graphs and handwriting inputs.
☆ Accepting video signal (TV, VCR, DVD), and showing dynamic images as well as graphs and animations.
☆ The control computer can act as a workstation on network, and read real-time data from specified computer, then show them on its display.
☆ Various methods for images display, and easy replacement for arranged programs whenever (including play sequence, time length, etc.)

Module

Pixel Pitch: 10mm; Pixel density: 10000dots/ m2
Size of Module (mm): 320(W)*160(H); Pixels of Module: 32 * 16;

This quotation includes LED modules(OPTO/Silan chips), 20pcs waterproof cabinets, power supplies, software, 1pcs sending card, 8pcs receiving cards, 1pcs DVI card, some spare parts and also wooden packaging boxes.

◆ Main Spare Parts (Free of Charge)

●Please pay attention to the followings:
1、Trade term: FOB Shenzhen
2、Payment Terms: By T/T, 30% down payment, balance to be paid before delivery
3、Quotation validity time: 1 month
4、Packing details: Packed by plywood case, 2 cabinets per case
5、Production lead time:20 working days after receipt of down payment, balance to be paid before delivery
6、After sales services:2 years warranty is offered. Within the period, if failures occur due to quality problem of the screen body, send the defective parts to us and we will repair them for free. However, half of freight should be borne by our customers. Once the warranty period expires, only materials cost will be charged if defective parts are sent back to us.

Overall of whole LED Display System

Tungsten-halogen lamps are frequently used as a near-infrared light source in Infrared spectroscopy.

Halogen lamps were used on the Times Square Ball from 1999 to 2006. However, from 2007 onwards, the halogen lamps were replaced with LED lights. The year numerals that light up when the ball reaches the bottom still use halogen lights.

Normally available in 12 V, with many also in 6 V and/or 24 V versions.

• Single filament, in 55 W and 100 W versions:
  • H1 axial filament, older style base
  • H2 axial filament
  • H3 transverse filament, heat-resistant cable for “hot” lead
• H4 dual-filament headlamp, 55 W to 100 W low beam, high beam varies from 60 W to 130 W
• H5 (similar to H4 but it have larger connector)
• H7

Architectural

• Linear in various sizes and power
  • R7S: linear halogen lamp measuring 118mm. Also known as a double ended halogen lamp.

• Dichroic reflector spots

Home use

With the help of some companies such as Philips and Sylvania, halogen bulbs have been fitted for use with standardized household fittings, and can be another choice as a replacement for incandescent light bulbs.

Stage lighting

• PAR light

Additionally, it is possible to get a sunburn from excess exposure to the UV emitted by an undoped quartz halogen lamp. To reduce unintentional UV exposure, and to contain hot bulb fragments in the event of explosive bulb failure, general-purpose lamps usually have a UV-absorbing glass filter over or around the bulb. Alternatively, lamp bulbs may be doped or coated to filter out the UV radiation. When this is done correctly, a halogen lamp with UV inhibitors will produce less UV than its standard incandescent counterpart.

Handling precautions

Any surface contamination, notably fingerprints, can damage the quartz envelope when it is heated. Contaminants will create a hot spot on the bulb surface when the bulb is turned on. This extreme, localized heat causes the quartz to change from its vitreous form into a weaker, crystalline form that leaks gas. This weakening may also cause the bulb to rapidly form a bubble, thereby weakening the bulb and leading to its failure or explosion, and creating a serious safety hazard. Consequently, manufacturers recommend that quartz lamps should be handled without touching the clear quartz, either by using a clean paper towel or carefully holding the porcelain base. If the quartz is contaminated in any way, it must be thoroughly cleaned with rubbing alcohol and dried before use.

Halogen lamps are manufactured with enough halogen to match the rate of tungsten evaporation at their design voltage. Increasing the applied voltage increases the rate of evaporation, so at some point there may be insufficient halogen and the lamp goes black. Over-voltage operation is not generally recommended. With a reduced voltage the evaporation is lower and there may be too much halogen, which can lead to abnormal failure. At much lower voltages, the bulb temperature may be too low to support the halogen cycle, but by this time the evaporation rate is too low for the bulb to blacken significantly. There are many situations where halogen lamps are dimmed successfully. However, lamp life may not be extended as much as predicted. The life span on dimming depends on lamp construction, the halogen additive used and whether dimming is normally expected for this type.

The function of the halogen is to set up a reversible chemical reaction with the tungsten evaporating from the filament. In ordinary incandescent lamps, this tungsten is mostly deposited on the bulb. The halogen cycle keeps the bulb clean and the light output remains almost constant throughout life. At moderate temperatures the halogen reacts with the evaporating tungsten, the halide formed being moved around in the inert gas filling. At some time it will reach higher temperature regions, where it dissociates, releasing tungsten and freeing the halogen to repeat the process. In order for the reaction to operate, the overall bulb temperature must be higher than in conventional incandescent lamps. The bulb must be made of fused silica (quartz) or a high melting point glass (such as aluminosilicate glass). Quartz being very strong, the gas pressure can be higher, which reduces the rate of evaporation of the filament, permitting it to run a higher temperature (and so efficacy) for the same average life. The tungsten released in hotter regions does not generally redeposit where it came from, so the hotter parts of the filament eventually thin out and fail. Regeneration of the filament is also possible with fluorine, but its chemical activity is so great that other parts of the lamp are attacked.

It is possible to see a live demonstration of the Tungsten-Halogen cycle in this accelerated video.[8] The lamp is equipped with an open tube that permits the halogen gas to be withdrawn and re-introduced as desired. When switched on, the filament is operating in a vacuum. After a few seconds the bulb is observed to blacken; this is caused by tungsten atoms that evaporate from the filament and condense on the bulb wall. Once completely blackened, the halogen gas is re-introduced back into the bulb. It quickly begins to react with the tungsten that has been deposited on the relatively cold bulb wall, and transports it back to the hot filament. The result is that the wall is returned to its original clarity. In this experiment the concentration of halogen gas used is higher than normal so as to achieve the rapid clean-up. In a standard lamp, the speed of the halogen regenerative cycle is much slower, but it operates continuously to prevent the bulb from blackening and thus maintaining a constant light output during lamp life.

Quartz Iodine Lamps, which used elemental iodine, were the first commercial halogen lamps, and were launched by GE in 1959. Quite soon, bromine was found to have advantages, but was not used in elemental form. Certain hydrocarbon bromine compounds gave good results. The first lamps used only tungsten for filament supports, but in some designs it has been possible to use molybdenum — an example being the molybdenum shield in the H4 twin filament headlight for the European Asymmetric Passing Beam.

High temperature filaments emit some energy in the UV region. Small amounts of other elements can be mixed into the quartz, so that the doped quartz (or selective optical coating) blocks harmful UV radiation. Hard glass blocks UV and has been used extensively for the bulbs of car headlights.Alternatively, the halogen lamp can be mounted inside an outer bulb, similar to an ordinary incandescent lamp, which also reduces the risks from the high bulb temperature. Undoped quartz halogen lamps are used in some scientific, medical and dental instruments as a UV-B source.

For a fixed power and life, the efficacy of all incandescent lamps is greatest at a particular design voltage. Halogen lamps made for 12 to 24 volt operation have good light outputs, and the very compact filaments are particularly beneficial for optical control (see picture). The range of MR-16 (50 mm diameter) reflector lamps of 20 W to 50 W were originally conceived for the projection of 8 mm film, but are now widely used for display lighting and in the home. More recently, wider beam versions are available designed for direct use on supply voltages of 120 or 230 V.

It also gives light of a higher color temperature (see below) that increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament. The halogen lamp can operate its filament at a higher temperature than a standard gas filled lamp of similar power without loss of operating life. This gives it a higher compared to a non-halogen incandescent lamp.

Alternatively, it may be designed to have perhaps twice the life with the same or slightly higher efficacy. Because of their smaller size, halogen lamps can advantageously be used with optical systems that are more efficient.

For a supply voltage V near the rated voltage of the lamp:

• Light output is approximately proportional to V ^3.4
• Power consumption is approximately proportional to V ^1.6
• Lifetime is approximately proportional to V ⁻¹⁶
• Color temperature is approximately proportional to V ^0.42

This means that a 5% reduction in operating voltage will more than double the life of the bulb, at the expense of reducing its light output by about 20%. This may be a very acceptable trade off for a light bulb that is in a difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings). “Long-life” bulbs take advantage of this tradeoff. Since the value of the electric power they consume is much more than the value of the lamp, general service lamps emphasize efficiency over long operating life. The objective is to minimize the cost of light, not the cost of lamps.

The relationships above are valid for only a few percent change of voltage around rated conditions, but they do indicate that a lamp operated at much lower than rated voltage could last for hundreds of times longer than at rated conditions, albeit with greatly reduced light output. The Centennial Light is a light bulb which is accepted by the Guinness Book of World Records as having been burning almost continuously at a fire station in Livermore, California, since 1901. However, the bulb is powered by only 4 watts. A similar story can be told of a 40-watt bulb in Texas which has been illuminated since September 21, 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, but is now in an area museum.^[69]

In flood lamps used for photographic lighting, the tradeoff is made in the other direction. Compared to general-service bulbs, for the same power, these bulbs produce far more light, and (more importantly) light at a higher color temperature, at the expense of greatly reduced life (which may be as short as 2 hours for a type P1 lamp). The upper limit to the temperature at which metal incandescent bulbs can operate is the melting point of the metal. Tungsten is the metal with the highest melting point, 3695 K (6192°F). A 50-hour-life projection bulb, for instance, is designed to operate only 50 °C (90 °F) below that melting point. Such a lamp may achieve up to 22 lumens/watt, compared with 17.5 for a 750-hour general service lamp.

Lamps designed for different voltages have different luminous efficacy. For example, a 100-watt, 120-volt lamp will produce about 17.1 lumens per watt. A lamp with the same rated lifetime but designed for 230 V would produce only around 12.8 lumens/watt, and a similar lamp designed for 30 volts (train lighting) would produce as much as 19.8 lumens/watt. Lower voltage lamps have a thicker filament, for the same power rating. They can run hotter for the same lifetime before the filament evaporates.

The wires used to support the filament make it mechanically stronger, but remove heat, creating another tradeoff between efficiency and long life. Many general-service 120-volt lamps use no additional support wires, but lamps designed for “rough service” or “vibration service” may have as many as five. Low-voltage lamps have filaments made of heavier wire and do not require additional support wires.

Very low voltages are inefficient since the lead wires would conduct too much heat away from the filament, so the practical lower limit for incandescent lamps is 1.5 volts. Very long filaments for high voltages are fragile, and lamp bases become more difficult to insulate, so lamps for illumination are not made with rated voltages over 300 V. Some infrared heating elements are made for higher voltages, but these use tubular bulbs with widely separated terminals.

Lamp bases may be secured to the bulb with a cement, or by mechanical crimping to indentations molded into the glass bulb.

Miniature lamps used for some automotive lamps or decorative lamps have wedge-bases which have a partial plastic or even completely glass base. In this case, the wires wrap around to the outside of the bulb, where they press against the contacts in the socket. Miniature Christmas bulbs use a plastic wedge base as well.

Lamps intended for use in optical systems (such as film projectors, microscope illuminators, or stage lighting instruments have bases with alignment features so that the filament is positioned accurately within the optical system. A screw-base lamp may have a random orientation of the filament when the lamp is installed in the socket.