Transistor have become one of the essential elements of modern technology. Transistors are found in smartphones, digital cameras, and electronic games, as well as in desktop and laptop computers, and a modern microprocessor usually contains hundreds of millions of transistors, although the most designs It contains more than 2 billion transistors. So what is a transistor and it types? and what it role in electronic circuits?
what is a transistor ?
Transistor is a name that consist of a combination of the words transfer and resistor, is part of the family of semiconductors with three active electrodes, used to control the flow of electric current, and since its invention in the 1940, transistors have revolutionized the world of modern communications, where the transistor enters into Manufacture of a very wide range of different electrical devices, such as: Computer, mobile, smartphone, robots, games, pocket calculators, and complex electronic systems used in industry.
A transistor is a semiconductor material contains silicon (or sometimes germanium), It is divided into three regions, if the middle region is a positive semiconductor and the two surrounding regions are negative semiconductors, if the middle region can be a negative semiconductor in this case The two outer regions are positive semiconductors. So we can conclude that there are two types of transistor.
- NPN: central region is a positive semiconductor.
- PNP: central region is a negative semiconductor.
How the transistor works ?
The transistor works in a way called (traditional mechanical switching), which connects or cuts off the flow of electric current, by connecting or disconnecting the two ends of the wires, where the transistor contains a signal that tells the device to connect or disconnect, and thus the device can be turned on or off, and therefore the transistor It has the property of control, and we conclude from this that the transistor controls the movement of electric electrons, as its work does not depend on connecting or cutting the current, but its work also lies in controlling the amount of electric current passing through, in addition to that it alters or amplifies electronic signals, and thus allows The individual can control the device by adjusting the circuit board.
The transistor also performs a variety of electrical tasks, due to the ease of electrical current flowing through it by controlling using the low-power control signal located at the three metal terminals of the transistor.
Types of transistor :
Bipolar Junction Transistor or BJT :
- PNP Transistor
- NPN Transistor
> Field Effect Transistor or FET
Junction Field Effect Transistor or JFET :
- N-Channel JFET
- P-Channel JFET
Metal oxide semiconductor field-effect transistor or MOSFET :
- Unijunction Transistor or UJT
- Depletion mode N-Channel MOSFET
- Depletion mode P-Channel MOSFET
- Enhancement Mode N-Channel MOSFET
- Enhancement Mode P-Channel MOSFET
- NPN Darlington Transistor
- PNP Darlington Transistor
shapes of transistors :
how to check a transistor by multimeter digital :
step 1 :
We connect the COM to the Emitter, then we connect the volt input to the Base :
- If there are reading, the transistor is intact.
- If there are no reading, the transistor is broken.
step 2 :
We connect the COM to the Collector, then we connect the volt input to the Base :
- If there are reading, the transistor is intact.
- If there are no reading, the transistor is broken.
