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Author
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Topic: Elmo projectors
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David Pannell
Phenomenal Film Handler
Posts: 1072
From: Horsham, West Sussex, UK
Registered: Nov 2004
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posted November 19, 2004 01:13 PM
Hello everyone.
I just joined this forum, and am looking forward to sharing some experiences etc. with you. However, my first launch into the forum comes with two questions.
The first concerns an Elmo E-80 Standard 8 projector which I recently purchased for a ridiculously low sum, and is in mint condition, having been used only 3 - yes, 3 times since new; but that's another story. The machine came complete with original handbook in its plastic sleeve, and leather (rexine) carrying case etc. etc.
However, it takes mains voltage lamps, and is adjustable from 100 volts to 240 volts. The nameplate on the machine states: 240 volts / lamp 750 watts max. (This would be the A1/9 type).
BUT the handbook states: lamp 750 watts max. up to 170 volts / 500 watts for all voltages. (A1/7)
I should state here that I am a professional electrical engineer, and as such, the handbook does not appear to make sense, as, for the same wattage lamp, the current would be half at 240 volts of what it would be,say, at 120 volts. So clearly the current drawn is not the issue. Also this clearly conflicts with the nameplate.
Is there something about the lamp filament arrangement or construction that I am not aware of? All technical explanations gratefully - thank you.
Second question - does anyone have a spare handbook for the Elmo ST600 please? Original, scanned or photocopy would be most gratefully paid for.
With best regards to all,
Dave.
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David Pannell
Phenomenal Film Handler
Posts: 1072
From: Horsham, West Sussex, UK
Registered: Nov 2004
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posted November 20, 2004 03:31 AM
Hi Colin and Mike,
Thank you both for your help thus far. Colin, for introducing me to The Forum, and Mike for suggesting Old Timer Cameras. OTC have in stock the owner's manual, service manual and full report for the ST 600. Also they have an owner's manual for the Bauer S 209 XL camera which I recently acquired, but minus the English manual - it has a German one.
I am very grateful for the interest and help shown by the members of the Forum, especially in such a short space of time!
Best to all,
Dave.
--------------------
Dave.
Valves and celluloid - a great combination!
Early technology rules OK!
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David Pannell
Phenomenal Film Handler
Posts: 1072
From: Horsham, West Sussex, UK
Registered: Nov 2004
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posted November 20, 2004 07:20 AM
To whom it may concern - plus anyone else interested.
Following my recent query regarding the projector lamp situation, and having difficulty understanding the reasoning behind the seemingly peculiar statement in the Owner's Handbook regarding the relationship between lamp voltage and wattage; I have now answered my own question.
The reason lies in the different configuration of the lamp filaments.
I have now carried our several observations and experiments with lamps of differing voltages and wattages, and have discovered that 500 watt A1/7 lamps, irrespective whether they are 115 volt or 240 volt, and 750watt A1/9 115 volt lamps all have the same filament arrangement, in that the filaments are concentrated into a relatively small area.
The 750 watt A1/9 240 volt lamp, however, has much longer filaments and they are spread over a wider area within the glass envelope.
It is now therefore clear to see that with the filaments covering a larger area, the condenser lens is only able to capture a proportion of the light emitted by the filaments, thereby resulting in less light being thrown upon the screen.
In my Elmo E-80, it is possible to adjust the position of the lamp relative to the reflector and condenser lens, to achieve maximum illumination, but I have now proven that the best arrangement is with a 115 volt / 750 watt lamp.
SO.....The advice given in the Handbook wasn't misleading after all, and although one can use practically any lamp, as it were, the recommendation does merit some advantages!
Thanks for your patience in reading my 'verbosity', I guess having an engineering mind is like a dog with a bone, still, if there's anyone out there wondering about lamps and things, i hope my little discourse has 'thrown some light on the subject'.
Dave.
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Dave.
Valves and celluloid - a great combination!
Early technology rules OK!
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