VACUUM TUBES ARJUN DUGGARAJU YONATHAN AYALEW. GENERAL INFORMATION HISTORY KEY PLAYERS TYPES.

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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?

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)

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

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

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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 -

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

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

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

VACUUM TUBES

A D V A N T A G E S

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

D I S A D V A N T A G E S

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

VACUUM TUBE IN GUITAR AMPLIFIER