An electronic device is a component that controls the flow of electrons to perform specific functions, such as amplification, switching, signal processing, or power management.
The three main types of electronic devices are passive components (resistors, capacitors, inductors), active components (transistors, diodes), and electromechanical components (relays, switches).
A diode allows current to flow in one direction only, acting as a rectifier, and it can also be used for voltage regulation, signal modulation, and switching.
A transistor is a semiconductor device used to amplify or switch electronic signals. It has three regions: emitter, base, and collector. By applying a small current to the base, it controls a larger current between the collector and emitter.
In an NPN transistor, the current flows from the collector to the emitter with the base controlling this flow. In a PNP transistor, the current flows from the emitter to the collector with the base still controlling the flow, but in the opposite direction.
An operational amplifier is a high-gain voltage amplifier with a differential input and usually a single-ended output. It is used in various applications like amplification, filtering, and mathematical operations.
Feedback in an op-amp circuit is used to control the gain and stability of the amplifier. It can be positive or negative, with negative feedback commonly used to stabilize the gain and reduce distortion.
Analog circuits process continuous signals that can have any value within a range, while digital circuits process discrete signals that have specific, distinct values, typically representing binary 0s and 1s.
A bipolar junction transistor (BJT) is current-controlled, while a field-effect transistor (FET) is voltage-controlled. BJTs have higher gain but more noise, while FETs are less noisy and have high input impedance.
An oscillator generates a continuous periodic waveform (sine, square, etc.) without an input signal. It works by using positive feedback to sustain oscillations at a desired frequency.