A multifaceted reflector (usually abbreviated MR) light bulb is a reflector housing format for halogen as well as some LED and fluorescent lamps. MR lamps have been originally designed to be used in slide projectors, but see use in residential lighting and retail lighting as nicely. They are suited to functions that require directional lighting corresponding to observe lighting, recessed ceiling lights, desk lamps, pendant fixtures, landscape lighting, EcoLight products retail display lighting, and EcoLight products bicycle headlights. MR lamps are designated by symbols equivalent to MR16 where the diameter is represented by numerals indicating units of eighths of an inch. Common sizes for common lighting are MR11 (11⁄8 inches, 35 mm) and MR16 (16⁄8 inches, fifty one mm), with MR8 (8⁄8 inch, 25 mm) and MR20 (20⁄8 inches, sixty four mm) utilized in specialty functions. Many run on low voltage moderately than mains voltage alternating current so require a energy provide. 3,314,331 for a miniature reflector lamp in 1967. The innovation was utilizing the lamp rim, somewhat than the base, as the reference plane for EcoLight products focusing.

This allowed extra flexible electrical mounting preparations and more exact focusing. Most MR lamps encompass a halogen capsule (or, bulb) built-in with a pressed glass reflector with a base conforming to bi-pin GU5.Three normal. The reflector controls the route and spread of mild cast from the lamp. Some lamps use an aluminum coating as a reflector. Others use selective dichroic coating that reflects seen light and permits infrared radiation to cross through. This kind reduces heating of illuminated objects since less infrared radiation is current in the sunshine beam. Nevertheless, EcoLight products dichroic lamps must only be used in compatible fixtures that can dissipate the heat. Dichroic lamps must not be fitted to recessed or enclosed luminaires with the IEC 60598 No Cool Beam symbol. The brightness of MR lamps could be adjusted when used with acceptable mild fixtures and dimmers. Nonetheless, the shade temperature changes considerably when the lamp is dimmed, shifting dramatically to the hotter finish of the spectrum.

Like all halogen lamps, MR lamps produce significant heat and care should be taken to avoid contact with pores and skin or proximity to flammable materials when the lamp is on or has been on just lately. Halogen lamps (18 lm/W typical) are more power efficient than regular incandescent lamps (15 lm/W typical) however nonetheless fall far behind other more-recent sorts akin to fluorescent lamps (80-one hundred lm/W), gasoline discharge lamps (100-200 lm/W depending on types), and LEDs (125-a hundred and fifty lm/W typical in vibrant white depending on type). With both types of incandescent bulbs, helpful life can be significantly shortened if their filaments experience mechanical shock or vibration. Using an electronic transformer with a smooth start function can considerably lengthen life, as it reduces the characteristically high inrush present that occurs initially when the lamp is chilly. Dimming also extends life significantly. MR lamps, like all quartz-halogen lamps, produce some undesirable ultraviolet gentle. Often, this should be filtered out.

Additionally, the quartz capsules of the lamps could rupture or explode upon failure of the lamps. For these two causes, some MR lamps include a cowl glass that serves as an integrated ultraviolet filter and explosion shield. MR16 lamps lacking this cover require using a fixture that incorporates an external piece of glass particularly designed to provide both ultraviolet and bodily protection. MR lamps are available in 10-75 watt energy rankings (150-800 lumens). MR lamps most frequently operate at 12 volts, though they are additionally obtainable in different voltages. These lamps use a bi-pin connector for energy: 12-volt MR11 bulbs normally use a GU4 base, and 12-volt MR16 bulbs often use a GU5.3 base. The frequent 12-volt MR16 lamps, therefore, require a ferromagnetic or digital transformer-generally misnamed as a ballast-to transform the 120- or 230-volt mains voltage to the extra-low voltage required by the lamp. Certain MR lamps can operate immediately on the mains voltage. These lamps sometimes use a GU10 turn-and-lock base, so they cannot be unintentionally interchanged with low-voltage lamps.

GU10 is distinguished from the decrease-voltage MR lamps by the U-shaped ceramic base mount with a ten mm (pin middle-to-middle distance) 2-pin bayonet mount. MR16 lamps with an integrated transformer are also out there. These lamps have screw bases to fit customary medium-base Edison sockets. MR lamps are generally accessible in range of colour temperatures, from about 2700 Okay to 7000 K, to satisfy varied functions. Retrofit lamps that generate light by a special principle but makes use of the MR kind-factor can be found. For instance, LED-primarily based MR16 lamps seem much like halogen lamps and may be utilized in most fixtures designed for MR lamps. The identical is true of MR11-appropriate LED lamps. Fixtures designed for halogen MR16 or MR11 lamps that use digital transformers might must be retrofitted with LED-suitable transformers. There may be a large variety of designs, varying significantly with regard to beam width, light color, effectivity and luminous energy.