Frequetly Asked Questions
LED Duty Cycle
Many traditional halogen lamps (such as the 64514) required a duty cycle. This means that you could run the light for roughly 15 minutes and then had to leave the light off for 15 minutes. This preserved the length of the lamp, but added a severe limitation to the fixtures effectiveness.
Modern LED sourced fixtures do not require a duty cycle. A Light Emitting Diode is a semiconductor that uses much less energy to produce the same amount of electroluminescence. Thus, they generate less heat, and there is less stress on the fixture, eliminating the need for a duty-cycle.
LED Lamp Life
Modern LED sourced fixtures have an estimated lamp life of up to 10,000 hours. That is over 416 days of continuous use. If you consider the following average use of an LED fixture for a dance club, DJ, or live band, you can see that it will provide years of useful service:
- 16 Hours Continuous Use per week, say Friday and Saturday night
- 10,000 hour expected lifespan / 16 hours use = 625 weekends of use.
- 625 weekends of use = 12 year lifespan!
Solid state devices such as LEDs are subject to very limited wear and tear if operated at low currents and at low temperatures. Many of the LEDs produced in the 1970s and 1980s are still in service today. Typical lifetimes quoted are 10,000 to 100,000 hours but heat and current settings can extend or shorten this time significantly.
The most common symptom of LED (and diode laser) failure is the gradual lowering of light output and loss of efficiency. Sudden failures, although rare, can occur as well. Early red LEDs were notable for their short lifetime. With the development of high power LEDs the devices are subjected to higher junction temperatures and higher current densities than traditional devices. This causes stress on the material and may cause early light output degradation.
LED Brightness
One look at an LED fixture will convince you of the brightness and brilliance of light produced by an LED fixture. One of the key advantages of LED-based lighting is its high efficiency, as measured by its light output per unit power input. Five-watt LEDs available with a luminous efficacy of 18–22 lumens per watt [lm/W]. For comparison, a conventional 60–100 W incandescent lightbulb produces around 15 lm/W.
RGB systems
White light can be produced by mixing differently colored light, the most common method is to use red, green and blue (RGB). Hence the method is called multi-colored white LEDs (sometimes referred to as RGB LEDs). Because its mechanism is involved with sophisticated electro-optical design to control the blending and diffusion of different colors, this approach has rarely been used to mass produce white LEDs in the industry. Nevertheless this method is particularly interesting to many researchers and scientists because of the flexibility of mixing different colors. In principle, this mechanism also has higher quantum efficiency in producing white light.
There are several types of multi-colored white LEDs: di-, tri-, and tetrachromatic white LEDs. Several key factors that play among these different approaches include color stability, color rendering capability, and luminous efficacy. Often higher efficiency will mean lower color rendering, presenting a trade off between the luminous efficiency and color rendering. For example, the dichromatic white LEDs have the best luminous efficacy(120 lm/W), but the lowest color rendering capability. Conversely, although tetrachromatic white LEDs have excellent color rendering capability, they often have poor luminous efficiency. Trichromatic white LEDs are in between, having both good luminous efficacy(>70 lm/W) and fair color rendering capability.
What multi-color LEDs offer is not merely another solution of producing white light, but is a whole new technique of producing light of different colors. In principle, most perceivable colors can be produced by mixing different amounts of three primary colors, and this makes it possible to produce precise dynamic color control as well. As more effort is devoted to investigating this technique, multi-color LEDs should have profound influence on the fundamental method which we use to produce and control light color. However, before this type of LED can truly play a role on the market, several technical problems need to be solved. These certainly include that this type of LED's emission power decays exponentially with increasing temperature, resulting in a substantial change in color stability. Such problem is not acceptable for industrial usage. Therefore, many new package designs aiming to solve this problem have been proposed, and their results are being reproduced by researchers and scientists.
