Film-Tech Forum ARCHIVE: Light bulb changes

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Topic: Light bulb changes

Jon Bartow
Master Film Handler

Posts: 287
From: Massachusetts
Registered: Nov 1999

posted 05-15-2002 05:31 PM

The Genie lift people make a "spider" thing for some of their lifts so that you can use their lifts in a stadium seating enviroment. (four adjustable legs and a pltform that the lift sits on) I know they have some lifts at at least 40 feet. You should call around and do some research with different personal lift manufacturers. You might have to put out a few bucks initially, but the savings over say five or ten years could be considerable.
Jonathan

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Gordon Bachlund
Jedi Master Film Handler

Posts: 696
From: Monrovia, CA, USA
Registered: Aug 1999

posted 05-15-2002 06:14 PM

Another solution to lowering the voltage minimally to increase incandescent lamp filament life is to use a buck-boost transformer in buck mode. I have found that a 10% decrease in voltage increases lamp life remarkably.

In the best of all lighting designs (or retrofits), a single panelboard would feed the lighting circuits only (assuming incandescent fixtures, not a mix of fluorescent or HID), and a properly-sized buck-boost transformer interposed ahead of the panel, wired for a 10% voltage decrease, would permanently limit lamp voltage irrespective of downstream dimmers on individual circuits or groups of circuits.

"Live better electrically?"

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 05-16-2002 07:04 AM

I checked a General Electric Stage/Studio & Projection Lamp Characteristics Calculator. Here is an example for a tungsten lamp:

A lamp rated for 120 volts, operating at 120 volts, will have 100% of its rated life, and 100% of its light output.

If the operating voltage is reduced to 110 volts, the life is 3 times longer, and the light output is reduced to about 70%.

At 100 volts, the life is 10X, and the light output is about 50%.

At 90 volts, the life is 50X, and the light is only 38%.

Boosting the voltage to 130 volts, the life is reduced to 35% of rated life, but light output is increased by a factor of 1.3X.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

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Jerry Chase
Phenomenal Film Handler

Posts: 1068
From: Margate, FL, USA
Registered: Nov 2000

posted 05-16-2002 09:09 AM

The caveat to reducing voltage is that while AVERAGE life may be increased, the weak lamps in the lot will still burn out first, and instead of being replaced at one year they might wait five years for replacement.

I'd be seriously inclined to go back to the architect and ask WTF he was smoking when he did the design. The threat of bad publicity, a letter to the A.I.A., and unhappy customers might make him find a solution for you.

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Scott Norwood
Film God

Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99

posted 05-16-2002 10:03 AM

As an alternative to reducing the lamp voltage, consider buying 130-volt bulbs for essentially the same result. The color temperature is slightly different, but they will definitely last longer and are cheaper than the traffic-signal bulbs with heavy-duty filaments.

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Craig Hanham
Film Handler

Posts: 79
From: Wellington, New Zealand
Registered: Oct 2001

posted 05-16-2002 08:08 PM

Look on your blueprints and see how much space between ceiling and roof, or is it one of those retarded architecturally designed barns where the roof is the ceiling?
Anyway back to the point, how much roof space? $4000 will go a fair way to making cat walks between roof trusses.

Quote from Rowan Atkinson "If an Architect comes and asks if he can design your bulding, for gods sake be firm F--K OFF!!".

Beware RANT MODE ON
Architects should be left to doing the pretty drawings leave the building design work and construction supervision to the engineers and builders.
If you want a totally useless edifice to fill a city block which cant be used for any pratical purpose by all means call in the architects and their fellow idiots the accountants and .......
Rant Mode OFF
Nuff said

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