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About a year ago, General Electric invented the hybrid
halogen / compact fluorescent light bulb. When
electricity is first supplied to one of these bulbs (which
look like a CFL stuffed inside of the glass of a regular
light bulb) the halogen light comes on, producing both
light and heat.
Once the heat from the halogen bulb
has warmed up the CFL, the halogen bulb turns off and
the CFL turns on.
This is a pretty neat combination -- the lamp reaches
full brightness the instant power is applied, and yet,
under normal use, the bulb is as efficient and long
lasting as any other CFL.
The problem that I see with it, is that if any of the
three components involved -- the halogen bulb, the
fluorescent bulb, or the electronics -- fails, the entire
unit must be tossed away.
This idea attempts to solve that problem, by making
both the halogen light and the fluorescent light
replaceable, using readily available, off the shelf bulbs;
if it catches on, the electronics would also be
separately replaceable, too.
We start with a ceiling fixture which takes (for
example) a 40 Watt circline fluorescent light. Add to
that fixture, between ten and fifteen 10 watt 12 volt
halogen lamps, arranged in a circle, just inside of the
circline bulb's circumference. Both types of bulb are
quite common and readily available in most hardware or
lighting stores. Add to this appropriate electronics to
light the halogen lamps when power is first applied, and
switches to the fluorescent once that has warmed up.
The number of halogen lamps would be selected so that
the amount of light given off by them is about the same
as (within 10% of) the amount of light given off by the
fluorescent tube -- this would make the transition fairly
unobtrusive to anyone not looking directly at the
To make the transition even less noticeable, the fixture
might switch over by gradually dimming the halogen
lamps and brightening the fluorescent lamp over a
period of several second to a couple of minutes.
||Light fittings including a Circline fluorescent and an incandescent globe were common decades ago; the incandescent globe acts as the ballast for the fluorescent. It is a good synergy, as some of the otherwise wasted ballast power gets converted to incandescent light, which supplements the uneven spectrum of the fluorescent.
||[spidermother] link, please?
||Modern electronic ballasts are quite efficient, so there's
no need to run both the halogen lamps and the
fluorescent lamp at the same time, once the fluorescent
has warmed up. The only reason I even suggest doing
so, is for a less noticeable transition from one to the
||Also, fluorescents are now available in colors that are
much more pleasant than "cool white" so there's little
need to supplement them with incandescent light.
||I agree with all your points; I mainly mentioned those hybrid fittings for history, interest, and prior art. I think they are mentioned in the Wikipedia "fluorescent light" article.
||However, incandescent globes do make excellent ballasts - the total efficiency can approach that of electronic and inductive ballasts, as long as the voltage drop across the incandescent globe is small compared to that across the ballasted device. Their resistance increases with current, so they give better stability than an ohmic resistor. (Source - my own tinkering, where I've used light globes as ballast for battery charging and LEDs, and achieved surprisingly good measured efficiency.)