What's the big red wheel for?
What's the big red wheel for?
Yup, 1950's 60's vintage. I remember these things very well. Probably auto transformers inside. If the slider on the transformer was not adjusted properly it would run off the end of the winding thus causing a loud snap along with lots of sparks at full load. Very entertaining. BTW, the door on the side is probably access to the 3 phase bus bar for the ablilty to connect auxiliary equipment. Ah the old days.Just so we're all on the same page here: it's understood that without regard to the title of the post, what is pictured is likely a product of the
1960's ?
+1 That's why you had a light crew instead of a board op. You actually had to have a touch for running one to make it look good.Yup, 1950's 60's vintage. I remember these things very well. Probably auto transformers inside. If the slider on the transformer was not adjusted properly it would run off the end of the winding thus causing a loud snap along with lots of sparks at full load. Very entertaining. BTW, the door on the side is probably access to the 3 phase bus bar for the ablilty to connect auxiliary equipment. Ah the old days.
Several years ago I spent two days in the Orpheum theatre in Wichita, KS re-rigging their movie screen. This was the lighitng system that was partially still in use. Its the original lighting controls that were installed in 1922.
Wish these were better... it was several years ago and taken with my blackberry in a very dark corner of the theatre.
Hence the term and reason for ghost load....(Thus, lots of extra fixtures in the basement lighting up the floor to make the numbers right.) ...
Not quite; there was some leeway. Exactly how much leeway, I can't recall....A resistance plate dimmer! On those, you had to match up the load exactly. If it was a 2k plate, you had to have a 2k load, or it wouldn't make it to black. ...
Later the same article states:
which would be 83.3% of capacity.Typical ratings of these dimmers [the two common sizes of piano boards: 14x3K, 12x6K] were 2500-3000W and 5000-6000W.
So it's either 75%, 80%, 83.3%, or some other %. Anyone know for sure? I believe one of my old textbooks contains the mathematical formula; I'll look it up if no one can answer definitively.
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