1. VACUUM TUBES ARJUN DUGGARAJU YONATHAN AYALEW

2. GENERAL INFORMATION HISTORY KEY PLAYERS TYPES

3. HISTORY & BACKGROUND Who first discovered the idea of Vacuum tubes? Where was the first Vacuum tube invented? Who was It invented by? What was is it first used for?

4. TYPES OF VACUUM TUBES Electrodes( Electron Emitters) 2 electrodes + 1 cathode + 1 anode = 1 Diode (1904) 3 electrodes + 1 cathode + 1 anode = 1 Triode (1906) 4 electrodes + 1 cathode + 1 anode = 1 Tetrode(1926) 5 electrodes + 1 cathode + 1 anode = 1 Pentode(1928)

5. Edison: “Edison Effect” Fleming: Invented and patented the first tube De Forest: Starts the Electronic revolution with the invention of the Audion Tube KEY PLAYERS

6. Coolidge: Invented x-ray tubes Schottky: Invented the tetrode (multiple grid vacuum tube) Langmuir: Observed emission and their behavior In vacuum tubes which lead to a creation of a variety of tube types KEY PLAYERS

7. MORE ON VACUUM TUBES HOW IT WORKS WHERE THEY'RE USED ADVANTAGES AND DISADVANTAGES

8. HOW IT WORKS Converts heat to electricity Vacuum tubes can take weak signals and make then stronger (amplify) Tubes can also start and stop the flow of electricity instantly (switch) Glow when its turned on (heat from the cathode) Anode + no air (vacuum)Transfer of energy Filament helps the amplification of energy. Cathode -

9. Have been around for ~10 years “One way mirror” sun’s radiation is absorbed but can’t escape (93% absorbed & 7% lost to reflection) Vacuum wall prevents any losses by conduction /convection Work better in lower temp unlike flat solar panels More expensive than flat panel but cost has been driven down due to demand WHERE THEY’RE USED: VACUUM TUBE SOLAR PANELS

10. Also known as valve amp, were the first type of guitar amplifiers Heat is converted to electricity which is then added to boost the weak guitar signal. Can switch from clean to distorted sound easily Warmer tone / full tone Still around because of sound quality! WHERE THEY’RE USED: GUITAR AMPLIFIERS

11. Vacuum Tube vs Transistors Both can switch electricity on and off Tubes, similar to light bulbs, generate a lot of heat and burn out Transistors are much smaller and have longer life spans Assisted in the construction of more advanced circuits Important to the development of modern machine WHERE THEY’RE USED: COMPUTERS

12. VACUUM TUBES ADVANTAGES Can be replaced easily if they fail Can be used in a wide range of applications (radios, amplifiers, strobe lights, juke boxes…) Provide better sound quality in professional sound equipment DISADVANTAGES Heavy Generate a lot of unwanted heat Require at least 11 sec to warm us compared to transistors which are instant Require a lot of power

13. VACUUM TUBE IN GUITAR AMPLIFIER