A multifaceted reflector (often abbreviated MR) gentle bulb is a reflector housing format for halogen as well as some EcoLight LED and fluorescent lamps. MR lamps had been originally designed to be used in slide projectors, but see use in residential lighting and retail lighting as properly. They are suited to functions that require directional lighting reminiscent of monitor lighting, recessed ceiling lights, desk lamps, pendant fixtures, panorama lighting, retail display lighting, and bicycle headlights. MR lamps are designated by symbols such as MR16 the place the diameter is represented by numerals indicating models of eighths of an inch. Widespread sizes for common lighting are MR11 (11⁄8 inches, 35 mm) and MR16 (16⁄8 inches, 51 mm), with MR8 (8⁄8 inch, 25 mm) and MR20 (20⁄8 inches, sixty four mm) used in specialty purposes. Many run on low voltage reasonably than mains voltage alternating present so require a energy supply. 3,314,331 for a miniature reflector lamp in 1967. The innovation was utilizing the lamp rim, relatively than the base, as the reference plane for focusing.

This allowed extra versatile electrical mounting arrangements and EcoLight extra exact focusing. Most MR lamps include a halogen capsule (or, bulb) integrated with a pressed glass reflector with a base conforming to bi-pin GU5.Three standard. The reflector controls the route and unfold of mild solid from the lamp. Some lamps use an aluminum coating as a reflector. Others use selective dichroic coating that reflects visible gentle and allows infrared radiation to pass by way of. This sort reduces heating of illuminated objects since much less infrared radiation is current in the light beam. Nonetheless, dichroic lamps must only be utilized in appropriate fixtures that may dissipate the heat. Dichroic lamps must not be fitted to recessed or enclosed luminaires with the IEC 60598 No Cool Beam image. The brightness of MR lamps will be adjusted when used with appropriate mild fixtures and dimmers. However, the color temperature modifications considerably when the lamp is dimmed, shifting dramatically to the hotter end of the spectrum.

Like all halogen lamps, MR lamps produce important heat and care must be taken to avoid contact with skin or proximity to flammable materials when the lamp is on or has been on lately. Halogen lamps (18 lm/W typical) are more vitality efficient than regular incandescent lamps (15 lm/W typical) however nonetheless fall far behind different more-latest varieties comparable to fluorescent lamps (80-a hundred lm/W), gasoline discharge lamps (100-200 lm/W relying on types), and LEDs (125-one hundred fifty lm/W typical in shiny white relying on style). With each sorts of incandescent bulbs, helpful life might be significantly shortened if their filaments expertise mechanical shock or vibration. Using an digital transformer with a comfortable start function can considerably lengthen life, because it reduces the characteristically high inrush present that occurs initially when the lamp is cold. Dimming also extends life significantly. MR lamps, like all quartz-halogen lamps, produce some undesirable ultraviolet gentle. Usually, this must be filtered out.

Additionally, the quartz capsules of the lamps may rupture or explode upon failure of the lamps. For these two reasons, some MR lamps embody a cowl glass that serves as an built-in ultraviolet filter and explosion shield. MR16 lamps lacking this cowl require using a fixture that incorporates an external piece of glass specifically designed to provide each ultraviolet and physical protection. MR lamps can be found in 10-75 watt energy scores (150-800 lumens). MR lamps most often function at 12 volts, although they're additionally available in different voltages. These lamps use a bi-pin connector for energy: 12-volt MR11 bulbs usually use a GU4 base, and 12-volt MR16 bulbs often use a GU5.3 base. The widespread 12-volt MR16 lamps, subsequently, require a ferromagnetic or digital transformer-sometimes misnamed as a ballast-to convert the 120- or 230-volt mains voltage to the extra-low voltage required by the lamp. Certain MR lamps can operate directly on the mains voltage. These lamps usually use a GU10 turn-and-lock base, EcoLight LED so that they cannot be by accident interchanged with low-voltage lamps.

GU10 is distinguished from the decrease-voltage MR lamps by the U-formed ceramic base mount with a 10 mm (pin center-to-heart distance) 2-pin bayonet mount. MR16 lamps with an built-in transformer are additionally available. These lamps have screw bases to fit standard medium-base Edison sockets. MR lamps are generally out there in vary of coloration temperatures, from about 2700 Ok to 7000 Okay, to fulfill various purposes. Retrofit lamps that generate mild by a different principle but uses the MR kind-factor are available. For instance, LED-primarily based MR16 lamps seem much like halogen lamps and might be used in most fixtures designed for MR lamps. The same is true of MR11-appropriate LED lamps. Fixtures designed for halogen MR16 or EcoLight LED MR11 lamps that use electronic transformers might must be retrofitted with LED-appropriate transformers. There may be a wide number of designs, varying significantly with regard to beam width, EcoLight light colour, effectivity and luminous energy.