Omachron LED LightCard (TM) explained.

Omachron has been doing research and development for over 41 years and have been doing LED research for over 16 years.  A number of our products have gone through multi-year real life testing to ensure that a statistically meaningful number of samples achieve the performance claims for the product and we have CSA, UL and Energy Star ratings for our products.  

We published a blog article "Re-inventing the Light Bulb" to provide the essential benefits to the widest audience possible and this is a more technical summary follow-up this article.

Many people understand that an incandescent bulb lasts about 1,000 hours and that a fluorescent or compact fluorescent light (CFL) lasts about 5,000 hours before they totally fail.  Many people are less familiar with the failure mode of LED bulbs and various manufacturers use different standards to describe operating life which adds to the confusion.

The performance of LED light bulbs and fixtures is based upon the efficiency and operating life of three subsystems: the electronics which provides the required current to the LED, the LED, and the thermal management system which regulates and maintains the temperature of the LED.  If the electrical current supplied to an LED by its electronics is properly regulated, and if the temperature of the LED itself is carefully controlled, LEDs can last for many years.  The performance of the three subsystems must be considered as follows.

The power supply is a critical element in an LED based lighting product.  Power supplies can be designed and manufactured with different efficiencies and power factors.  We have seen power supplies in LED lights with efficiencies as low as 65% and power factors as low as 0.5 +/- 10%.  This means that if the LED needs 5W of power, the power supply will require 7.69W to operate which significantly reduces the efficiency of the system.  In addition many power supplies in LED light bulbs incorporate one or more electrolytic capacitors.  Electrolytic capacitors are rated by temperature and in simple terms, the higher the temperature rating, the longer the life of the capacitor will be in a given applications.  The temperature of the capacitor has a huge effect on life. The relationship between life and temperature follows a chemical reaction formula called Arrhenius' Law of Chemical Activity which says that life of a capacitor decreases for 50% for every 10 degree Celsius rise in temperature within limits.  We have designed a good heat sink and we have chosen high temperature capacitors such that we have a 160,000 hour design life and a 60,000 hour test life at room temperature.  In addition, we have used high temperature accelerated aging in order to extrapolate our long term life.  In addition, the power supply in our lighting fixtures is modular and replaceable therefore the fixture, heat sinks, lenses and decorative elements remain and only the LED LightCard? and the power supply are recycled.  We have a 91% efficient power supply with a 95% +/- 3% power factor power supply which means if our LED needed 5W of power, our power supply would require only 5.26W to supply this power.  If a power supply fails, the bulb fails.  Our power supplies are dimmable and maintain their efficiency and power factor over a 5:1 turn-down ratio which maintains our efficiency even when dimmed. 

Not all LEDs are created equal.  LightCard(TM) products use LEDs with an output of up to 213 lumens per watt whereas many LED bulbs use LEDs which only produce 65 to 100 lumens per watt as they are less expensive.  In addition, these luminous output ratings are laboratory output levels under ideal cooling conditions typically rated at 20C to 25C.   Omachron uses more energy efficient LEDs than many other manufacturers.  According to Cree, Osram, Samsung, and a number of other manufacturers of high power LEDs, "the majority of LED failure mechanisms are temperature-dependent and that elevated junction temperatures cause light output reduction and accelerated chip degradation.  Simply stated, as the temperature of the LED increases, the light output for a given input power and the operating life is reduced.  Many companies mount their LEDs onto fiberglass circuit boards which do not conduct heat away very efficiently and as such the LED temperature at the junction is often 110C to 120C which significantly reduces both its operating life and efficiency of the LED.  We mount our LEDs on an aluminum circuit board which is mechanically held against a large heat sink by two spring clips.  As a result, Omachron maintains an LED temperature of about 65C to 75C, which provides us with a luminous output of approx. 190 lumens per watt.  Therefore, our LED mounted on our heat sink only requires a power input of about 2.37W to provide 450 lumens of light, and 4.21W for 800 lumens of output.  

Many other companies which use less efficient LEDs and less efficient power supplies have the compounding problem of poor thermal management because the total amount of heat that they need to get rid of is much higher.  A further issue with LED bulb designs is that they typically do not fail “open circuit” which means they just stop giving off light altogether like incandescent and fluorescent bulbs do.  

LEDs typically suffer from a slowly diminishing output level where the light level they produce slowly fades away.  Our light bulbs are Energy Start certified to maintain more than 70% of our light output after 35,000 hours.  Although a number of companies still make claims of 50,000 or even 100,000 hours for their bulbs, ethical companies such as Philips, which make excellent products, rate their bulbs as having a life of 15,000 hours and produce 800 lumens of light with 7W of power as illustrated below.  Many other LEDs require 8 to 10W of power to provide 800 lumens of light.   

An Omachron LightCard(TM) module mounted into an Omachron bulb which provides 800 lumens of light requires only 4.43W of power which is 36.7% less than the high quality Philips bulb and which is as much as 55.7% less than other bulbs with similar light output. 

The easily replaceable LED LightCard(TM) module has a lower cost than conventional LED light bulbs combined with Omachron bulbs featuring long life power supplies and optimized heat sinks provides a more energy and lower cost of ownership solution versus current LED light bulb.

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