The Facts about L.E.D. Bulbs
By: Al Smyth Ė Portatree Timing Systems, Inc.
When L.E.D. Bulbs were first introduced, they caused a firestorm of controversy both in the Sportsman and Pro Categories. The biggest change was the instant on characteristic of the L.E.D bulb which was causing the drivers to leave the starting line anywhere from .03 to .04 quicker. In the Pro Categories, drivers that were average on the tree were becoming Great Drivers ( low Reaction Times) and drivers that were already quick on the tree were RED Lighting. The sportsman racers who raced on the Full Tree in the no delay box categories were all dealing with RED Lights and trying to adjust their cars and even themselves to slow down .03 to .04 seconds !
L.E.D. stands for Light Emitting Diode and they are instantly illuminated when current is applied. L.E.D. bulbs use a cluster of L.E.D.ís to form a lamp that can be seen by the driver. The typical L.E.D. bulb used in the drag race application has 39 L.E.Dís and uses either a magnified or straight-faced lens. In one design the bulb is driven directly from 110 A.C. where the other design uses a 12-volt D.C. transformer. The 110 A.C. version is much lighter (weight) of the two. The L.E.D bulb replaced the incandescent flood lamps that heat a filament that in turn glows to produce light. The time it takes for the filament to heat enough for the driver to see is dependent on voltage input and the ambient light of day or night. This time can vary substantially.
Driverís RTís used to vary from day racing to night racing with Incandescent bulbs because the filament could be seen heating up sooner when it was dark which made driverís leave earlier. The L.E.D. bulb is instant on which makes the driver very consistent from day to night. The L.E.D. bulb is also more consistent in appearance as the incandescent bulbís coating used to vary from a light shade to a dark shade depending on the manufacturer.
The L.E.D bulbs cost about $60 each and the incandescent bulbs cost about $12. To outfit an entire tree would cost over $600 if done in L.E.D.ís, but most tracks and drivers use only the Amber L.E.Dís as if they wait to see green they are way too late and of course, no one wants to see RED !! Cost is the main reason that only the larger tracks are using L.E.D. bulbs and most tracks only use them on the driver side of the tree. Some of the larger tracks even use green and red L.E.D.ís.
The future will bring L.E.D. bulbs to the stage bulb of the Christmas tree. This will allow the driver to know if he has a solid stage or a high-speed flicker that is sometimes undetectable with an incandescent light bulb. The cost for these will be even higher than the L.E.D. flood lamp, but it is still better for the racers to know that they are properly staged than to RED Light !