Halogen Lamps

A halogen lamp is an ordinary incandescent lamp with a few modifications. The fill gas includes traces of a halogen as well as an inert gas. Halogens are a group of gas molecules. The purpose of the halogen is to return evaporated tungsten to the filament.

As tungsten evaporates from the filament, it usually condenses on the inner surface of the bulb. The halogen is chemically reactive, and combines with the tungsten deposit on the glass to produce tungsten halides which then evaporate easily. When tungsten halide reaches the filament, the intense heat of the filament causes the halide to break down, releasing tungsten back to the filament. The halogen cycle keeps the inner surface of the bulb clean. This lets halogen lamps stay close to full brightness as they age.

In order for the halogen cycle to work, the bulb surface must be very hot, generally over 480 degrees Fahrenheit. The halogen may not adequately vaporize or fail to adequately react with condensed tungsten if the bulb is too cool. This means that the bulb must be small and made of either quartz or a high strength, heat resistant glass.

It is for these reasons that halogen lamps should burn at full brightness. This is not to say that you cannot dim halogen lamps, however if the lamp is dimmed, the halogen cycle is inefficient thus shortening lamp life considerably.

Since the bulb is small and fairly strong, the bulb can be filled with gas to a higher pressure than usual. This slows down the evaporation of the filament. The higher pressure and better fill gases can extent the life of the lamp and/or permit a higher filament temperature that results in higher efficiency.

A halogen lamp is often 10 to 20 percent more efficient than a similar incandescent lamp. Halogen lamps may also have two to three times as long a lifetime as ordinary lamps, sometimes with an improvement in efficiency of up to 10 percent.

The construction and principle of operation of incandescent filament and tungsten-halogen lamps are similar; however, the halogen regenerative cycle enables a tungsten-halogen lamp to provide the following benefits compared to a traditional incandescent lamp:

• Halogen lamps have longer life.
• Halogen lamps have a higher correlated color temperature (CCT) thus makes colors appear rich, vibrant, and natural.
• Halogen lamps have higher efficacy.
• Halogen lamps do not produce bulb blackening.
• Halogen offers crisp white light that allows dramatic accents and is excellent for accenting.

Bi Pin Halogen Lamps

All low voltage Ambiance® Lighting Systems use bi-pin halogen lamps. The T3 G4 Bi-Pin halogen lamp is available from 5-20 watts and the T3 or T4, GY6.35 lamp (available in either 12 volt or 24 volt versions) is available from 20-50 watts. This lamp is used for general and accent lighting providing an efficient source for enhancing color and texture. Some familiar uses of the T3 and T4 bi-pin halogen lamp are seen in recessed lighting and pendants.

Some lamp manufacturers are producing bi-pin halogen lamps with built in reflectors. Also, technology is available to allow halogen, bi-pin lamps to be used without shielding.

Mirror Reflector Lamps (MR)

For over two decades, the MR16 (Mirror Reflector) lamp has revolutionized low voltage lighting. With the onset of this lamp, which had been used extensively in Europe, it allowed domestic manufacturers to design smaller fixtures for residential and commercial use. The popularity grew as the technology expanded to allow lighting designers more latitude in their designs for recessed and track lighting. Today, the MR16 and related lamps is an integral, if not essential, part of most lighting designs. The Ambiance® Lighting System uses MR16 lamps in track lampholders as well as in recessed fixtures.

The following represents the features and benefits of the standard MR16 family of lamps:

• Standard Dichroic Reflector
• Superior beam performance
• Cost effective display and accent lighting
• Choice of six beam angles and consequential CBCP (Center Beam Candlepower)
• 4000-hour lamp life

"Dichroic" is defined as the property of having more than one color, especially when viewed from different angles. Dichroic glass is a high-tech spin-off of the space industry. Thin layers of metallic oxides are deposited upon the surface of the glass in a high temperature, vacuum furnace.

Dichroic coatings transmit certain wavelengths of light, while reflecting others, thus creating an interference-effect that is iridescent in nature. Improvements in dichroic technology have often eliminated the iridescent colors once found emanating within and from the dichroic reflectors of MR lamps.

The development of the IR (infrared) MR16 lamps represents the latest innovation and improvement to low voltage halogen technology that increases lamp efficacy (LPW) up to 25% more than standard MR16 lamps. These lamps are coated with an infrared reflective film on a precisely formed halogen capsule that redirects waste heat back to the lamp filament and reducing the energy needed to deliver light. Originally introduced in 37-watt versions that yield the same light output as standard 50-watt MR16 lamps, the IR product family has been expanded to include 50-watt IR versions, which replace up to 71-watt standard MR16s. The new 50-watt lamp is available in a variety of distribution patterns (NSP, SP, FL).

Infrared (IR) lamps also feature a hard-coated, dichroic reflector that delivers consistent, white light throughout their 4000-hour average rated life. All lamps have a UV-control capsule to eliminate UV-B and UV-C radiation.

Other earlier improvements to the MR16 family of lamps include "Constant Color" where the consistency of color (no color shift) is important, long life lamps up to aluminized reflector lamps where finish coordination is a consideration, and covered lamps for use in open fixtures. Each manufacturer has their own trade names for the different versions of MR16 lamps on the market today. Gaining some popularity are the 120 volt versions of the MR16 lamp, but the lamp life can be less than the low voltage versions and some color temperature issues might still remain.

The MR11 and MRC11 lamps are part of the bi-pin family of halogen lamps. This series provides precise beam control while also emitting a cool beam to reduce heat while lighting sensitive objects.

Ambiance® Lighting System fixtures using MR11 series lamps accept a maximum of 20 watts each. A variety of beam spreads are available including narrow spot (NSP), spot (SP), and narrow flood (NFL). Use different beam spreads to achieve desired effects to highlight a variety of sizes and objects.

Depending upon the fixture used, MR11 lamps come with an open front (MR11) or a glass cover (MRC11). The MR11 is for use in an enclosed fixture while the MRC11 is for use in an open fixture. The glass cover helps to keep the lamp from becoming dirty as well as preventing incidental contact while the lamp is functioning and prevents injury should the lamp experience non-passive end of life.

The following represents some features and benefits of the standard MR11 family of lamps:

• Standard Dichroic Coating
• Maximum light output from ultra compact fixtures
• High CRI in merchandise display case
• A choice of spot or flood versions with good CBCP (Center Beam Candle Power)
• 3000-hour lamp life

MR8 lamps (one inch in diameter) allow for even smaller fixture designs than MR11 and MR16 lamps. Having similar characteristics to other MR lamps, the MR8 is as tiny as they come for any application within the Ambiance® LX Lighting System.

These miniature lamps are perfect for applications requiring task lighting, display lighting or accent lighting where the lamp needs to be as inconspicuous as possible.

The following represents some additional features and benefits of the standard family of MR8 lamps:

• 1 inch diameter
• Standard bi-pin GZ4 base
• 3050° K Color temperature
• 2,000 average life
• Integrated cover glass
• Cool Beam Dichroic Reflector

"Xelogen" lamps

A recent "buzzword" promotes the use of Xelogen lamps in low voltage fixtures. A Xelogen lamp is basically a Xenon lamp either in wedge base or bi-pin form. For further information regarding Xenon lamps, refer back to the xenon section as the characteristics of Xelogen are very similar.

120 volt, G9 Base Halogen Lamps

Ambiance® Transitions kits and component fixtures, and their 120 volt pendants, use a lamp that has been popular in Europe and Canada for years. Similar in operation to the 12 volt versions, these lamps are excellent for general and accent lighting. The innovative G9 pinched quartz lamp structure eliminates arcing sources and creates a self-fusing lamp. It combines a bright, compact source with UV-Filter quartz, which means the G9 allows small, sleek fixtures to be designed without the need for expensive transformers and heavy glass shields.

The "G9" in G9 is the base designation. The new base is a simple snap in / pull out design that is perfect for getting lamps into and out of small fixtures. The long life and energy efficiency of G9 lamps make them ideal for use in residential, commercial and industrial buildings.