F. H. Richardson's bluebook of projection (1935)

Record Details:

Title:
F. H. Richardson's bluebook of projection
Date:
1935
Publisher:
New York : Quigley Publishing Company, Inc.
Volume:
F. H. Richardson's bluebook of projection
Leaf #:
000570
Language:
English
Subjects:
Motion Pictures, Motion Picture Technology
Collection:
Books
Format:
Books
Contributor:
Media History Digital Library
Sponsor:
{"Media History Digital Library","Jeff Joseph"}
Coordinator:
Media History Digital Library
Description:
Date Added:
August 01, 2024
Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




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.

552 RICILUWSOX'S BLUEBOOK OF PROJECTION Grid Bias Supply (26) The grid bias must be smooth d. c. The voltage required is a small fraction of the plate voltage needed for the same tube. The current required in Class A is zero, since the "load" of the grid circuit is a condenser, through which d. c. does not flow. In Class B circuits there will be some flow of grid current when the grid swings positive. (27) There are three methods of providing grid supply. The simplest is by use of a small dry battery, called the "C" Battery. This would connect to terminals "C" of Figure 128, negative to grid, and positive to cathode. A second method uses a voltage drop introduced into the d. c. filament supply (Figure 137). A resistor is wired in series between the negative side of the filament and the negative pole of the filament supply battery or other d. c. source. The grid is wired to the negative side of that resistor, and is therefore negative with respect to filament by the extent of the voltage drop the resistor creates. A0 d °s Fig. 137. — Method of obtaining grid bias by voltage drop in filament circuit. The method of Figure 137 is not applicable to large tubes that need a grid bias of higher value than their full filament voltage. The circuit of Figure 138 is used with such tubes, as well as with heater types. The resistor shown in that diagram is in series with the plate or "B" circuit. The grid of Figure 138 is negative with respect