The transistor is probably the most important electronic device known, from inductive detectors normally used in industry to microprocessors used in home computers, in all of them we can find electronic devices composed of one or more transistors.
The transistor was invented in 1947 and came to replace the three-electrode thermionic valve or also called triodium, basically composed of silicon and allows the passage of current through N-type and P-type semiconductor crystals.
How does a transistor work?
The transistor has a current input (can be the emitter - E), a current output (can be the collector - C) and a signal input (the base - B) that when it acts facilitates the transmission of electrons between the emitter and the collector.
In other words, transistor acts as a switch, only current will flow between E and C when acting B.
The three working regions that habe a transistor are: Cut-off, saturation and active.