Not only do projection lamps have a use in overhead projectors, but they also have some application in machines or viewers.  One of the most common for many different brands of projectors and viewing equipment is the EKE projector lamps.  Although the needs of computer based presentation has increased recently, there are still many applications of overhead projectors in use everyday.  The need for simple visual communication makes it a popular option for years to come.  There are a wide variety projectors which use the EKE lamp, and they all have the same exact function.  In fact, some companies who make these projectors have swapped bulb types for any number of reasons.  The main purpose for a bulb like this is the light it puts on a screen, how well it fills out the screen space.  The brightness, as most people call it, needs to be enough to gain good contrasts of objects, writing or overhead transparencies.

All of the EKE projector lamps regardless of the brand, have the same shape, and sometimes the exact same shape of another lamp which might have a different voltage or wattage.  That's one of the reasons they're not interchangeable.  Almost always, the voltages are different and the lumen output as well.  The EKE projector lamps are 150 watts and 21 volt.  In regards to the shape, many bulbs have the same shape as MR16 halogen bulbs, but that's where the similarity ends.  The MR16 has a few basic voltages and does not have the watts that are needed to produce the light that an overhead projector needs.  Another thing to remember, because these have a high light output, that usually means they have a much shorter life.  The life is shorter, the rating is only 200 hours, so it's good to turn off the lamp when it's not in use.  Every instance of time you don't have it on means the lamp will last longer. Another caution is that these bulbs should not be touched with your skin. The skin oils can react with the glass and there can be some reactions which will shorten the lamp life. If they are touched, you might see a bubbling of the glass over time, but it's not instantaneous. If you do touch it, simply wipe it thoroughly with a soft cloth.

Another thing to keep in mind when replacing these is that they are identified by a 3 letter code on the bulb itself.  You'll see it somewhere on the back or the top if it's more like a bulb as opposed to a reflector type lamp.  Sometimes you'll see the code as EKE as described here or ENX, FXL, DAY, DYS, EVD, ELH or something similar to that.  The ANSI 3 letter code identifies that bulb as to the shape, wattage, voltage and any other standard information.  Unlike other types of bulbs, these have some standards across various manufacturers, the only thing that varies is quality.  We have two of the best manufacturers of all types which are Sylvania and Eiko.

In summary, EKE lamps are used specifically for the machine or overhead projector they are made to operate with.  Of course, you will need projectors that will have the correct circuitry for the projector bulbs.  Whatever type of projection lamp you have, you can get what you need while getting the best quality possible.  We have a large inventory of projector bulbs for nearly every type of lighting application in the field.  If you need help identifying a projector bulb, our customer service representatives can help you determine what you have.