What is a tube?
The electron tube is the earliest telecommunication good amplification device, which is sealed in a glass container, the cathode electron emission part, the control grid level, the acceleration grid level, the anode lead wires are welded on the hanging base, and the control grid in the vacuum is controlled by the electric field. Level. Inject electronic modulation signal. It can be amplified in positive level.
Practical use of electron tubes
radio, microwave, etc.
The characteristics of the tube
1. When the cathode of the electron tube starts to be used, the cathode has not reached the operating temperature. If the high voltage is applied immediately, its life will be shortened (not very understandable) 2. The outside is glass, and the inside is vacuumized
.
The history of the development of electron tubes
Edison was the first inventor.
Edison effect: When the filament is heated to a certain state, it will radiate electrons.
This is the discharge phenomenon
2.
British physicist Fleming.
Change this phenomenon into reality.
Put a small metal bucket , put it on a filament, and found that the radiated electrons will increase, and the direction will not change. So he named this actual phenomenon a diode. 3.
American
De Forest
improved the diode, and in the diode A grid of metal filaments is added between the cathode tube and the anode tube, which has the functions of fast switching and amplification, and can accept miniature electrical signals. ps: In the 19th century, the triode patent sold for 390,000 yuan. There are so
many
Since then, humans began to use the first radio. Woohoo NB.
But the electronic tube at that time was very big.
4.
Bell Labs Shockley
used germanium, batteries, gold wires, and springs to make an electronic amplifier, and
the transistor was born.
5.
Shockley invented the germanium crystal transistor for electrical Miniaturization laid the foundation.
Since then, mankind has entered the semiconductor era.
6.
Shockley built a new laboratory on the east coast of the United States.
Eight experimenters proposed to use silicon to make integrated circuits.
7.
Eight fairy children proposed to start their own business. Founded their own company
. Made investments. Proposed to represent Noyce.
1957 Founded Semiconductor Corporation.
transistor
1. The earliest transistors relied on germanium, but the distribution of germanium was scattered, and the content was small, and it was not resistant to high temperature, so it could not be refined to a certain purity. 2. But the content of silicon was very large, and it was very
easy to purify. So it was made of silicon Crystalline silicon.
3. Using silicon to manufacture integrated circuits
4. Entering the era of integrated circuits