Many people show their passion on these lights so we can own benefits to the life. Some of the new LED lighting ideas are almost unbelievably good. One that I have already featured is the LED panel Light? After a visit to the importer, I now sees that this is only one of many very exciting lighting products – all using LEDs.
Some of the products include a bi-pin halogen led panel light. Just like any other light, it operates from 12V AC, but draws only a rated 8W. A visual comparison between a LED and halogen lamp reveals that the light output is a little lower (measured at 370 vs. 530 lumens at 850mm from the lamp), but the power difference is huge. Note that the visual difference is not as great as may be implied by the measured difference. My halogen lamp (which is used under my workbench so I can find things I’ve dropped) draws 50W including the “electronic transformer”, but the LED lamp draws only 6.48W, using either AC or DC.
Yes, that is a tiny fan you can see on the right. Because the lamp is so small, heat sinking the LEDs becomes an issue, so the fan was included to keep the temperature down. The fan is a 3-lead type, so the electronics knows if the fan stops and will flash the lamp as a warning. While standard halogen led panel light has been responsible for a number of house fires* because they get so hot, this is a very unlikely scenario with the LED replacement.
The ability to operate just fine with 12V DC is a benefit too, since it can be powered from a battery if desired. The electronics includes current limiting for the LED T8 light, so the light output does not vary as the voltage changes, until it drops below about 10V. Any DC voltage from 11V up to 15V only changes the current drawn – it falls as the voltage is increased, keeping the power usage about the same regardless of supply voltage.
With all electronics, maintaining the lowest possible operating temperature is important, and prolongs the life of the LEDs, ICs and other electronics. Fortunately, the latest LED lamps are getting much better at dissipating minimal power, and the amount of heat that needs removal is much lower than any other light source.
Many of the issues with current LED T8 technology are directly related to the fact that all currently available luminaries are made so that the lamp can be changed. We are entering a new era, where the light source will last so long that it will probably never require replacement. This makes it much easier to design the fittings to maximize heat dissipation to keep the LED tubes, and simple modules will replace the standard bulb-shaped lamp. Other than for replacement in existing fittings, the days of the bulb (or globe) as we currently know it is definitely numbered.
The LED T8 modules are each held in place by 4 metal thread screws, and the LEDs are under a molded plastic cover that is well sealed against moisture ingress and insect invasion. Each module has 28 LEDs, which I expect are about 1.2 Watts each. All LEDs are mounted onto a substantial aluminum based circuit board, which is then attached to the heat sink visible on the back of the module. There will always be losses in the power supply, but will be fairly low – I’d be guessing, but around 7-10W would be typical for a supply having a typical efficiency of 93-95%. On that basis, each panel has around 30-33W of power to the LEDs.
The forward voltage of white LEDs falls by about LED T8. The temperature coefficient may be anything for white LEDs, and as a result the temperature calculation can only ever be an estimate using this method. Measuring the heat sink temperature showed an almost identical temperature rise, so the calculation seems fairly close. If natural lights can bring more benefits to life then we can bring more to life.