Re: 750 watt halogen in a VM stereomatic

[P3D John Ohrt <johrt@xxxxxxx>]

P3D Elliott Swanson wrote:

> Assuming the socket can accomodate the extra draw, does anyone know the
> relationship of heat output between a 750 watt halogen and a 500 watt
> tungsten, taking into account the increased air circulation made possible
> from the smaller lamp? Would better HAG take care of it (or is it even
> necessary?) I know many people use 750 watt lamps in TDC 116 projectors
> and get away with it. The VM has a monster fan-- the thing sounds like an
> idling 747 jet airplane...

First does the halogen bulb really disappate 750 w or is it rated at the
equivalent of an 750 w tungsten bulb.

There is a big difference! and both ratings are used.  Check the bulb
and the packaging.  If it is the equivalent of a 750 watt tungsten lamp,
that is it is as bright as a 750 watt tungsten lamp, and then elsewhere
it should tell you the actual spec.

watts = volts * amps  (as a crude approximation for light bulbs)

Two of them must be specified and I believe it required to be specified
right on the bulb.  Typically it is volts and watts, but it may be volts
and amps.

If it is as bright as a 750 watt tungsten lamp, then you are probably in
good shape, because the actual power dissipated should be less than the
rated 500 watts.

If it truly dissipates 750 watts,  personally I wouldn't run it nor
would I reccommend anyone else do so.  That is like sticking a 100 watt
bulb into a ceiling ficxture rated at 60 watts.  If you burn your house
down because of it, don't be surprised if your insurance is void!

There is much more to worry about than the cooling of the bulb (which
shortens the life of a halogen bulb by the way).  Wires that fuse,
insulation that burns, glass that shatters from thermal stress etc.

Life is too short.  Do it right!

My $.02 Canadian

Regards,
John

--
John Ohrt,  Regina, SK, Canada
johrt@xxxxxxx


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