Halostar Maxi Spot AR70 - 41980SP M/160

The Halostar AR series was introduced by Osram in 1982, first with the smallest AR48 known as 'Mini Spot'. Originally it had no anti-glare shield, but that became a standard feature from 1984. In 1983 the AR70 'Maxi Spot' shown here made its debut, initially only in 20W and 50W ratings but extended to 75W in 1985. The industry-leading AR111 'Super Spot' was launched in 1984 as a 6V 35W product for very narrow beams, but rapidly expanded to higher wattage 12V lamps for projection of light over long distances.

The reflector is made from a sheet of spun aluminium, which was also available with gold anodised finish to achieve a warmer colour for indoor applications. Right from the start Osram favoured the use of capsules having axial filaments, to improve beam uniformity and facilitate the achievement of very narrow beam angles. An especially ingenious invention was the inclusion of an anti-glare shield, based on the sealed beam PAR lamps such as the popular 4515 pinspot. This absorbs the uncontrolled light which would normally exit the capsule without being controlled by the reflector, which can otherwise gives rise to acute glare. Not only did this black shield realise great optical improvements, it also facilitates easier installation and removal, and unexpectedly became a styling feature which propelled Osram's AR111 in particular into a leading market position.

Perhaps the only drawback of the AR lamps was their smooth reflector, which saw their popularity wane following the advent of the glass-reflector MR16 types with sparkling facetted dichroic mirrors. In an attempt to overcome this visual weakness, Osram upgraded its AR series during 1988 and 1989 to feature facetted aluminium mirrors.
Manufacturer: Osram GmbH 41980SP M/160
Lamp Power: 75 Watts  
Lamp Voltage: 12 Volts  
Lamp Current: 6.25 Amperes  
Cap Type: B15d Ni plated + Vitrite insulator
Bulb Type: AR-70 AR-22 in eighths/inch
Bulb Finish: Aluminium reflector Anti-Glare shield
Filament Type: C-8 Axial Single Coil
Atmosphere: Bromine, Krypton
Luminous Flux: 1,500 lm  
Luminous Efficacy: 20.0 lm/W  
Peak Intensity: 15,000 cd  
Beam Distribution: 10° to 50% peak
Colour Temperature & CRI: CCT: 3000K CRI: Ra 100
Chromaticity Co-ordinates: CCx: 0.452 CCy: 0.409
Rated Lifetime: 2000 hours to 50% survival
Burning Position: Universal  
Max. Overall Length: 50 mm 2"
Light Centre Length: N/A
Factory: Eichtstatt Germany
Date of Manufacture: July 1986 Date Code iT0
Original / Present Value: GB £7.70 (1988) GB £14.88 (2007)
 
References: 1) Wotan Halo Star Brochure - 1987
2) Wotan UK Lamp Catalogue - 1988
3) Wotan Specification News, Issue 7 - July 1988
4) Osram-GEC UK Price List - April 1988
5) German Patent 8,219,740U1 - Reflektorlampe, bestehend aus Reflektor und Halogenglühlampe - 1982