Projection lamps are always a subject of concern in the Audio Visual Community. What I find to be most troublesome from a technicians point of view, is that most end users of Audio Visual Equipment, in particular those who use Audio Visual Equipment that require the use of today's halogen projection lamps, are not aware of the special care required when handling these types of lamps. This lack of knowledge directly effects the life expectancy of theses halogen projection lamnps.
Lamp life has always been a concern for end users. Because of the intensity of today's halogen lamps, and the high operating temperatures,lamp life is considerably shorter than the old style incandescent lamps. Two of the most popular projection lamps found in Overhead Projectors today are the "ENX" and the "EYB". Most users don't realize that the rated average life of theses lamps is only 72 hours, a considerable difference from the 200+ hour rating for the incandescent projection lamps of yesterday's Overhead Projectors. Considering that Overhead Projectors in many cases are used a minimum of four to six hours a day, 72 hours comes around very quickly, sometimes giving the end user the false impression of short lamp life. When in reality the projection lamp is burning for its average expected life.
The most common application for halogen projection lamps in the Audio Visual Industry today is the Overhead Projector. The use of the old style incandescent lamps that were required to use 120 volts to operate in yesterday's Overhead Projectors Projectors, have for the most part become obsolete. Sure, you can still find Overhead Projectors that use this old technology in the Educational Community, but today's new Overhead Projectors no longer use these types of projection lamps. Today's Overhead Projectors use halogen lamps that are designed to burn at very high temperatures, yet in most cases only require 82 volts to operate. They produce a much brighter light output (referred to as lumens) and don't require the use of special reflectors or fans for cooling.
Now here is where the trouble seems to begin. Special care needs to taken when handling these halogen lamps, especially when installing them into your projector. They should never be handled with bare hands. The oils from the skin that remain on the projection lamp, can cause burn spots on the shell of the lamp when illuminated, causing the lamp to burn unevenly and causing damage to the lamp and ultimately shortening the life of the projection lamp.
The second cause for concern is how the lamp is seated into the lamp socket. If not properly seated into the socket the pins of the socket will ark between the socket connections and the projection lamp pins. This causes damage to the projection lamp as well as to the projectors lamp socket, shortening the life of both lamp and lamp socket. The projection lamp should be seated into the socket until you feel a slight snap as the lamp seats fully into the socket. This is by far the most common reason for lamp failure, and for that matter lamp socket failure.
There are of course other factors that determine lamp life, but these by far are the most commons reasons for premature failure that we see in our service department every day.
Mark Boehm is the president of M-B Electronics He has over 25 years of experience in the Audio Visual and Electronics Industry. You can contact M-B Electronics at 800-872-9456 or at:etbinc@comcast.com |
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