Re: Osram HWL E27 lamps? -- or - Watts hot and Watts not

["S. Hieber" <shieber at yahoo_com>]

 Hello again, Jacques:

I haven't seen these in use but I will share what I have
dug up.

"E27" refers to the base type & size, and "E27" is a
standard size screw-in base.  "HWL" refers to what Osram's
"blended" as opposed to "HID" or "High Pressure Sodium"
lamp. 

Here's a good brief description of a mercury-tungsten
blended lamp:

"Mercury tungsten blended lamps are mercury lamps whose
ballast is a tungsten filament located between the two
envelopes. The tungsten filament acts as an incandescent
lamp. In this way, no auxiliary is needed, they can be used
like incandescent lamps. 

Discharge in the quartz glass arc tube is started by a
starting electrode. The radiation generated by the electric
current through mercury vapour is only partly light,whose
invisible part is transformed into light by the fluorescent
powder on the inner surface of the outer envelope. "

I would suspect that these are not as efficient as some
other discharge/arcing bulbs.  But with a tungsten filament
involved, they will certainly have more red light than a
fluorescent usually has (unless red phosphors have been
purposely added).  BTW, the first fluorescents invented
used filaments as the ballast -- so these aren't new tech,
they date back to the 1930s!

The bulbs are also made under the Phillips label -- in fact
that's Phillip's description above.

Blended lamps often have a color rendering of about 40-60%,
not very good at all, and tend to be warm within their
"off-color" range.  Usually about 75% -80% is considered
acceptable.  Their chief advantage over fluorscents is that
they are smaller than fluorescents and do not require a
separate ballast (the filament is used as the ballast) so
can be used in standard fixtures.  I think their primary
uses are commercial/industrial rather than residential
(that tells you something about the appearance of colors).

You might do better with a compact fluorescent, even a
spiral coiled one with a standard screw base.  The
electronic ballast might give a slightly more efficient
bulb and one that happens to have better color rendering,
too.

Hope that helps,
Scott H.

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