“ UNDERSTANDING ELECTRONICS: VACUUM TUBES “ 1970 EDUCATIONAL FILM DIODES & TRIODES XD72594

Join this channel to get access to perks: Want to learn more about Periscope Film and get access to exclusive swag? Join us on Patreon. Visit Visit our website “Understanding Electronics: Vacuum Tubes” is a color, educational film from 1970. Presented by Universal Education and Visual Arts in collaboration with educators from both the Toronto and Scarborough Boards of Education, this film educates its audience on the history, makes and models, and applications of vacuum tubes/ electron tubes. The vacuum tube is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. Illustration Thomas Edison’s lightbulb (0:29). Filament (wire) in center of lightbulb (0:41). Animation “Edison Effect”/ Thermionic Emission (1:02). Animation continues: explanation of how Ambrose Fleming expanded on Edison’s findings (1:19). Close-up “cats whisker” crystal detector used in radios (1:33). Close-up electron tube, replaced cats whisker (1:35). Diagram Lee de Forest’s 1906 three-element “Audion“ triode vacuum tube (1:47). Close-up vacuum tube in lightbulb (2:24). Deconstructing parts of bulb: close-up cathode, pencil guides sight line (2:34). Anode: metal plate that collects the electrons (2:47). Anode and cathode inside glass cylinder (envelope) (2:53). Close-up of diode - tube with two electrodes (2:56). Diagram of electron flow based on charge of cathode (3:09). Two tubes with filament with addition of grid of fine parallel wires (3:28). Diagram triode electron tube (3:36). Close-up screen grid added to triode (4:07). Diagram tetrode - tube with four electrodes (4:22). Diagram of suppressor grip (4:34). Diagram pentode (4:44). Close-up black pentode tube - commonly used on radio and TV sets (4:50). Pentode in RF stage as voltage amplifier, on silver circuit grid (4:53). Pentode in power output stage as power amplifier (5:03). Examples various electron tubes on display table (5:12). Diagrams basic components of electron tube: anode, cathode, grids (5:16). Cathode turns red with head on metal plate (5:31). Cathode laying on red background coated in white substance (5:43). Wire mesh grids (5:51). Tubes in manufacturing stage: close-up hands using tweezers to place anodes, insulated with mica (5:58). Rows of completed electron tubes upside down on storage tray (6:20). Diagram how to identify tubes and their components in diagrams (6:23). Example of diagram in tube manual indicating how to identify each pin (7:07). Example circuit diagram from tube manual (7:16). Examples pulses of direct current read on oscilloscope after alternating voltage fed to diode tube circuit (7:33). Diode vacuum tube connected to red and black cables - explanation and visual of pulsating direct current (8:04). Two vacuum tube diodes set up side by side, attached to center-tap transformer (8:31). Oscilloscope screen of electrical currents - comparison between input and output voltage (9:31). Close-up of twin diode without vacuum tube (9:46). Close-up triode tubes laying side by side (10:00). Illustrated symbol for triode (10:04). Triode used as amplifier in experiment: scientist studies illustration of electrical grid set-up (grid bias voltage) (10:22). Incoming signal on oscilloscope (11:33). Close-up power amplifying tube (11:55). Power amplifier circuit - triode, input signal, power source, heater, output transformer (12:28). Incoming signal on oscilloscope (12:48). How to amplify the complete signal: circuit with addition of second amplifier tube, close-up of input transformer with center tap on secondary winding; center tap output transformer (13:10). Diagram of how circuit amplifies complete signal (13:25). Depiction of feed on oscilloscope (14:16). Various multiple electrode tubes lay spread on table (14:26). Diagram hexode tube (14:33). Diagram heptode tube (14:42). Diagram of Superheterodyne receiver - explanation how RF converted to IF (15:17). Comparative diagrams two types frequency changing circuits (15:40). Close-up twin triode used as amplifier in television channel selector (16:22). Electronic measuring instruments that use electron tube: Geiger Counter (16:39). Screen of complex radiation counter (16:50). Oscilloscope (16:53). Face of control and storage unit (16:57). Electron tube used in manufacturing: Close-up thermostat (17:01). Large industrial machine with programmed timing (17:14). Smoke detector (17:26). Electron microscope (17:51). Room filled with small/ medium-size machines that use electron tubes (17:58). This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit