We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
(b) The first cost, including installation, is lower for
the rectifier.
(c) The rectifier may be and usually is installed in
the operator's booth.
(d) In cases where it seems necessary that both arcs
be operated simultaneously for any purpose, the Motor Generator is the proper equipment. Some theatres operate two machines from a single rectifier by stealing the arc from one machine to the other, without any warming-up period.
Mercury Arc Rectifier Equipment.
The equipments now made for this service differ only in details and the descriptions of the outfits are, therefore, combined for sake of brevity, and mercury arc rectifiers have been recognized as standards for a number of years.
The equipments now made consist of a transformer regulating reactance, a bulb or tube, control mechanism, and an automatic starting device. The transformer and regulating reactance, which may be included as part of the transformer, are for the purpose of reducing the line voltage to the proper value and provide stability of the arc. The bulb or tube serves as an electrical valve, which prevents the flow of current in the wrong direction. The connections are such as to utilize current from two different parts of the transformer winding in such a manner as to secure continuous current, and the transformer is so designed that the pulsations are slight.
In order to compensate for variations in line voltage and to permit adjustments to be made to take care of variable conditions, such as film density, etc., means are provided for controlling the current, by changing connections of the reactance or transformer. These outfits are so arranged as to permit the operation of an A. C. arc as an emergency measure.
For convenience in operating and to permit the installation of the outfit at some distance from the operator, automatic starting devices are provided. These are such that the outfit is started by closing the line switch and striking the arc.
The over-all efficiency of the rectifier is approximately 70%. This represents the percentage power from the line, which is delivered in the form of power to the arc.
All outfits are designed so as to operate at full load continuously without temperatures that are unsafe.
Mercury Arc Rectifiers are made in 30, 40 or 50 D. C. amperes capacity, and can be made for service on any commercial A. C. circuit. The inherent characteristics of all outfits are such as to make the arc voltage at normal current highly efficient.