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.
1166 HANDBOOK OF PROJECTION FOR
details in this work, would only be a repetition, since the principles underlying it differ in no degree from those underlying the other systems described. The only difference lies in the details of construction, and in such matters the manufacturer will fully inform you when the equipment is placed in your charge.
On the wall directly in front of the projector is mounted a two-stage amplifier, which the current from the photo-electric cell passes through. This amplifier uses 112-A tubes.
MAIN AMPLIFIER.— The Cinephone main amplifier consists of two complete amplifier and power systems. The connection is such that merely by moving switch J, Fig. 425, the change is made from one to the other. By this it is meant that should one amplifier for any reason become defective, a change to the other complete amplifying unit may be made by throwing switch J. It is a good arrangement.
Referring to Fig. 425, A is the main A. C. switch for amplifying system. B is charge-discharge switch for batteries supplying the amplifiers next the photo-electric cell. C is the A. C. switch for charger circuit. D is the charge-discharge switch for the exciter lamp and main amplifier battery. E is the motor generator switch, to be used in territory where power is other than 110volt 60-cycle. F is the charge-discharge ammeter for circuits terminating at switch B. G is the voltmeter for measuring the voltage across the filament of vacuum tubes in main amplifier. When batteries are fully charged, this meter should read 12 volts. H is the charge-discharge ammeter for circuits controlled by switch D.