Olin Lathrop wrote:
>
> > What irks me is that the bulb manufacturers could
> > very easily add a 5% wire resistor into their filament
> > designs, and make bulbs that last almost forever.

> They are probably more concerned with efficiency.  Incandescent bulbs are
> already hideously inefficient, and adding the resistor makes the overall

As a businessman and small manufacturer I don't
think efficiency is an issue. If you know you sell
100k+ bulbs each month to a country why would you
make changes that reduced that figure?? It's profits
first, reliability and morality second.


> I'm no fan of incandescent bulbs, but they certainly last more than "a few
> weeks" around here.  We have 120V mains here instead of 240V.  Do the 240V
> bulbs really last that much shorter or were you exaggerating a bit or do you
> leave your lights on all the time?  Incandescent bulbs are inherently low
> voltage high current devices, and making a good 240V bulb is going to be
> harder than a good 120V bulb.
>
> How about using two 120V bulbs in series?


Yep the 240v bulbs really are that bad, see my calcs
for the worst case cold startup power and compare to
your calcs for 120v bulbs. Enormous difference. The
problem is not with leaving them on, it's cold starting,
every few weeks you switch the light on and it goes
"pop" and another $2 down the drain.

Using 2x 120v bulbs in series sounds excellent for
so many reasons, but imagine the downside, they are
hard to find here, and you have to replace each bayonet
fitting with two bayonet fittings. The resistor works,
its cheap, problem solved.

I have also started using high efficiency compact
fluorescents (bulb replacements) but if you have ever
opened one of these they use a lot of small parts run
very close to their limits, again designed to last
a number of weeks and fail.

I suppose lighting companies don't want to make failure
proof lighting?? Sure seems that way.
-Roman

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