1 Answer
A Bipolar Junction Transistor (BJT) is primarily used to **control the flow of current** in an electronic circuit. It acts as a **switch** or **amplifier** depending on the application.
BJTs come in two types: **NPN** and **PNP**.
Here’s how a BJT works in terms of controlling current:
1. **Amplification**: A small current at the base terminal controls a much larger current flowing between the collector and emitter. This makes the BJT suitable for amplifying weak electrical signals, such as in audio or radio-frequency circuits.
2. **Switching**: When used as a switch, a small current at the base allows a larger current to flow from the collector to the emitter (in an NPN BJT). If no current is applied to the base, the current between the collector and emitter is blocked, effectively turning the transistor "off." This makes BJTs useful in digital circuits for controlling power to different parts of a system.
In summary, BJTs control the flow of current between the collector and emitter, either by amplifying a small base current (in analog circuits) or acting as a switch (in digital circuits).
BJTs come in two types: **NPN** and **PNP**.
Here’s how a BJT works in terms of controlling current:
1. **Amplification**: A small current at the base terminal controls a much larger current flowing between the collector and emitter. This makes the BJT suitable for amplifying weak electrical signals, such as in audio or radio-frequency circuits.
2. **Switching**: When used as a switch, a small current at the base allows a larger current to flow from the collector to the emitter (in an NPN BJT). If no current is applied to the base, the current between the collector and emitter is blocked, effectively turning the transistor "off." This makes BJTs useful in digital circuits for controlling power to different parts of a system.
In summary, BJTs control the flow of current between the collector and emitter, either by amplifying a small base current (in analog circuits) or acting as a switch (in digital circuits).