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On Thu, 13 Dec 2012 09:15:28 -0800, John Larkin
wrote:

On Wed, 12 Dec 2012 09:01:59 -0500, z wrote:

On Tue, 11 Dec 2012 21:47:27 -0800, John Larkin
wrote:

On Tue, 11 Dec 2012 12:04:13 -0500, z wrote:

On Tue, 11 Dec 2012 08:35:17 -0800, John Larkin
wrote:

On Tue, 11 Dec 2012 10:17:58 -0500, z wrote:

On Tue, 11 Dec 2012 12:47:53 -0000, "john stone"
wrote:

Have a 10Watt, 12Volt Hologen lamp for a christmas decoration. But the
mains tranformer I have is only 6 Volts.

Apart from being a bit dimmer, would there be any other consequences running
at the lower voltage? Thanks.

At 6V the halogen cycle won't operate so you'll probably get
discoloration of the bulb after some time and perhaps the bulb won't
last as long (to the degree that it's a trade-off of lower power vs.
the elimination of the halogen cycle). Other than that, it'll
probably be a very yellow light at pretty low intensity.

We run a halogen (over our dinner table) from a dimmer. We seldom use it at full
brightness. It's about 10 years old and still on the original bulb.

The envelope is probably black by now.

No. Why should it be, if we seldom run it full brightness?

Because you DON'T run it at full brightness the envelope isn't cleared
by the halogen cycle. This is a common failure of halogen bulbs. They
get black, reducing their light output and fail early.

If there's hardly any evaporation, why would the bulb get black?

A faulty assumption doesn't bode well for any conclusions drawn.

Our dimmed halogen isn't black. And it's run for a couple of hours per day for
10 years now.

It must be *really* dimmed, unless it's also run for some hours at
full power. Every halogen I've dimmed has turned black after some
time.

Filamant evaporation
goes as some insane power of voltage. And when we do occasionally run it at full
voltage, won't the halogen cycle do its thing?

But you just said you rarely run it at full power. It can't if you
don't.

Are you now debating the difference between "rarely" and "occasionally"?

It makes a difference.