Green light bulb can faze the telly
April 22, 2007

THEY have been promoted by Gordon Brown, the chancellor, as vital to saving electricity and cutting greenhouse gases.

Now, in addition to their often murky powers of illumination, low-energy bulbs have been shown to bring another inconvenience in their wake - they disrupt television remote controls.

Scientists have found that the infrared waves given out by some models of the bulbs are almost exactly the same frequency as those from the hand-sets. Sometimes this means the controls fail altogether. On other occasions the channels may be spontaneously switched by the “impostor” rays of the bulbs.

For the same reason they can even stop a radio from receiving shortwave programmes.

The problem is likely to increase as more British households adopt the environmentally friendly compact fluorescent lamps (CFLs), which are up to 80% more efficient than conventional tungsten filament versions.

The drawback has been high-lighted by a study in Silicon Chip, an Australian electronics journal. The study comes at an awkward time for governments around the world. Australia has announced that conventional bulbs will be phased out and replaced by CFLs.

Brown announced last month he also wanted to end the use of inefficient light bulbs by 2011. This came a week after a European Union decision to phase out the traditional bulbs.

The CFL lasts far longer than conventional equivalents and a 22-watt version is designed to give out the same light as a traditional 100-watt bulb. The bulbs are estimated to have about 13% of sales in Britain. But the study reports: “If you have a CFL in the same room as your television or hi-fi system, the infrared remote control may not work at all - its signal will be completely blanketed by the modulated infrared from the CFL.”

The CFL’s infrared rays are emitted at a frequency of about 20-30kHz, says the report: household remotes work at a frequency only slightly higher.

CFL makers acknowledge the problem, although Philips said it had now been remedied on its products. General Electric admitted some CFLs could interfere with signals but it was “rare”.

Nick Flynn, 46, who runs a project management consul-tancy in Exmouth, Devon, replaced his light bulbs with CFLs two months ago.

Then he discovered the remote control for his 27in Sony flatscreen television had packed up. Flynn sent it to a repair shop, which found nothing wrong but charged him Ł100 for the check.

He phoned again to tell them the remote control was still not working. “It was only then that the guy on the phone said, ‘Have you recently changed your light bulb?’” said Flynn. “Now every time I need to change the channel I pull the plug on the lamp.”

(Source: The Sunday Times )