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Lightning ?


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hilldweller

Advancing years make night-time trips to the bathroom ever more frequent. Growing old is no joke, but it is better than the alternative. :)

Recently I have been aware of what appeared to be occasional lightning flashes as I try to get back to the land of nod.

Reasoning that lightening doesn't strike almost every night I lay awake with my eyes open and was surprised to find that the low energy CFL in the ceiling light was flashing very briefly about every 15 minutes.

I googled the problem and apparently it is a known problem where the lighting wiring is looped in and the live wire runs alongside the switched live.

Even if the switch is off, the capacitive coupling between the wires allows a tiny current to flow which slowly charges the smoothing capacitor to the point where the invertor gives a little blip and the tube flashes.

I cured the problem with a good old fashioned 100 W GLS bulb.

And before you all ask, it wasn't me flashing, I always wear pyjamas. lol

HD

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Advancing years make night-time trips to the bathroom ever more frequent. Growing old is no joke, but it is better than the alternative. :)

Recently I have been aware of what appeared to be occasional lightning flashes as I try to get back to the land of nod.

Reasoning that lightening doesn't strike almost every night I lay awake with my eyes open and was surprised to find that the low energy CFL in the ceiling light was flashing very briefly about every 15 minutes.

I googled the problem and apparently it is a known problem where the lighting wiring is looped in and the live wire runs alongside the switched live.

Even if the switch is off, the capacitive coupling between the wires allows a tiny current to flow which slowly charges the smoothing capacitor to the point where the invertor gives a little blip and the tube flashes.

I cured the problem with a good old fashioned 100 W GLS bulb.

And before you all ask, it wasn't me flashing, I always wear pyjamas. lol

HD

I think its quite well known that I am no fan of low energy bulbs, they are rubbish and hyped up beyond honest claims. As a physics teacher I am supposed to carry the official line on "energy saving" but after my own personal experiences with them I just can't do it out of my own honesty. In reality they take a long time to reach full brightness and when they do they do NOT produce the same light output as an equivalent higher wattage fillament bulb (electric companies and which? claim they do, I have proved, using both a photographic exposure meter and a home made grease spot photometer that they are not). When used the tube itself quickly darkens at the electrode ends and burn out fairly quickly having a shorter life than a tungsten fillament. They have very poor, "cold" colour temperatures, they flicker enough to cause headaches and oh yes, as hilldweller says, they flash. Also, the environmentalists will be disappointed to know that burnt out bulbs are very difficult to dispose of safely.

Bring back the old filament bulbs, it's worth paying extra on the electric bill for something less efficient and higher powered just for their quality and convenience.

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ukelele lady

Also, the environmentalists will be disappointed to know that burnt out bulbs are very difficult to dispose of safely.

I am glad you mentioned about the disposell of these bulbs Dave , I don't think this was fully thought out at all.

Why is it that most new things out today gives you the impression that we are going backwards instead of forwards?

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I am glad you mentioned about the disposell of these bulbs Dave , I don't think this was fully thought out at all.

Why is it that most new things out today gives you the impression that we are going backwards instead of forwards?

Fluoresecent tubes, which is what low energy bulbs really are in miniature, non-linear form (no new technology, public buildings and kitchens have been using long fluorescent strip lighting for decades) contain mercury vapour which gives out uv when excited by high energy electrons. The inner coating of the tube which gives it it's white colour is a beryllium compound which is fluorescent, ie it absorbs the uv and re emits it as visible light.

Both mercury and beryllium are highly toxic. Breaking one of these bulbs releases mercury vapour and beryllium compound dust both of which can be inhaled. Me and Stuart once accidentally broke a fluorescent strip light at school and it was considered an environmental disaster rather than a breakage.

In contrast fillament bulbs contain argon, an inert, unreactive gas which prevents the fillament oxidising and burning out. Argon is harmless, being unreactive and is a natural component of the air anyway, making up just under 1% of it. So if one of these gets broken there is no chemical risk at all, the biggest risk now being cutting yourself on broken glass while clearing it up.

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