Roman Black wrote:

>that in the 240vac mains countries we have many times
>the bulb failures in 120vac countries. Again the
>cold start power with a 240v bulb is MUCH worse than
>the same size 120v bulb.

For the same wattage, the current is half, so equal to the wire size.

But, the lower voltage, the thicker the wire, and so the wear of atoms boiling around is less for a lower voltage lamp.  If you want really long life of incandescent lamp, use low voltage lamps so the incandescent wire is thick, and halogen types as the boiled away atoms more efficiently is back deposited to the wire.

Also see i.e the OSRAM web page.

>I really do have a cupboard full of light bulbs
>and bulbs blow every few weeks. I have started using
>high-eff fluoros, but again with 240v mains these
>tend to die pretty quick, usually the power semis
>in them.

Probably just a badly designed brand.  See my previous post.

I have designed power supplies, and 240VAC really is no problem.
Higher voltage yes, but lower current, and it mostly is th ecurrent thet leads to heat, and heat leads to wear.  It is just a matter of correct design.

Most countries use 220..230..240 volts demestic, and there is reason for it.
In Sweden we left 110..127V systems in beginning of last century.

/Morgan

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