What is the transistor theory?
Transistors are current controlled solid-state devices that conduct current in proportion to an input current. For an NPN transistor, current flowing “into” the base leg of the transistor results in a proportionally larger current to flow between the collector and the emitter. …
How does a 2N3904 transistor work?
2N3904 Transistor as a switch In normal state, 2N3904 acts as reverse biased and there’s no conduction between Collector & Emitter. When small voltage applies at its Base Terminal(normally 5V), 2N3904 converts its state from reverse to forward biased and conventional current starts flowing from Collector to Emitter.
Why transistors are so important?
Transistors make excellent electronic switches. They can turn currents on and off billions of times per second. Digital computers use transistors as a basic mechanism for storing and moving data.
What type of transistor is 2N3904?
NPN bipolar junction transistor
The 2N3904 is a common NPN bipolar junction transistor used for general-purpose low-power amplifying or switching applications. It is designed for low current and power, medium voltage, and can operate at moderately high speeds.
How transistor changed the world?
Transistors transformed the world of electronics and had a huge impact on computer design. Transistors made of semiconductors replaced tubes in the construction of computers. By replacing bulky and unreliable vacuum tubes with transistors, computers could now perform the same functions, using less power and space.
What is a 2N3904 transistor?
The 2N3904 is an extremely popular NPN transistor that is used as a simple electronic switch or amplifier that can handle 200 mA (absolute maximum) and frequencies as high as 100 MHz when used as an amplifier.
What is the beta of a 4Ma bipolar NPN transistor?
A bipolar NPN transistor has a DC current gain, (Beta) value of 200. Calculate the base current Ib required to switch a resistive load of 4mA. Therefore, β = 200, Ic = 4mA and Ib = 20µA. One other point to remember about Bipolar NPN Transistors.
What is a NPN transistor?
NPN Transistor NPN Transistors are three-terminal, three-layer devices that can function as either amplifiers or electronic switches In the previous tutorial we saw that the standard Bipolar Transistor or BJT, comes in two basic forms. An NPN (N egative- P ositive- N egative) type and a PNP (
What are the construction and terminal voltages for a bipolar NPN transistor?
The construction and terminal voltages for a bipolar NPN transistor are shown above. The voltage between the Base and Emitter ( VBE ), is positive at the Base and negative at the Emitter because for an NPN transistor, the Base terminal is always positive with respect to the Emitter.