Electronic components are the fundamental building blocks used to design and fabricate electronic circuits. They are categorized based on how they handle electrical energy and signals. --- ## 1. Classification of Electronic Components Electronic parts are primarily divided into two main categories: **Passive** and **Active**. ### A. Passive Components These components cannot introduce energy into the circuit and do not require a power source to function. They store, dissipate, or filter energy. | Component | Symbol | Function | | :--- | :---: | :--- | | **Resistor** | R | Limits the flow of electrical current. | | **Capacitor** | C | Stores energy in an electric field; filters signals. | | **Inductor** | L | Stores energy in a magnetic field; resists changes in current. | ### B. Active Components These components rely on a source of power and can control the flow of electricity (amplification or switching). | Component | Symbol | Function | | :--- | :---: | :--- | | **Diode** | D | Allows current to flow in only one direction. | | **Transistor** | Q / TR | Acts as a switch or an amplifier for signals. | | **Integrated Circuit (IC)** | U / IC | A complex circuit of miniaturized parts on a single chip. | --- ## 2. Key Component Details ### Resistors Resistors are used to protect components (like LEDs) from excessive current. Their value is measured in **Ohms (Ω)**. - **Fixed Resistors:** Constant resistance. - **Potentiometers:** Variable resistance (e.g., volume knobs). ### Capacitors Capacitors act like tiny temporary batteries. They are measured in **Farads (F)**. - They are used to smooth out voltage fluctuations in power supplies. - They can block DC (Direct Current) while allowing AC (Alternating Current) to pass. ### Transistors The "brain" of modern electronics. - **BJT (Bipolar Junction Transistor):** Current-controlled. - **MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor):** Voltage-controlled; essential for computer CPUs. --- ## 3. Connecting Components To create a working device, these parts are mounted onto a **PCB (Printed Circuit Board)**. - **Through-Hole Technology (THT):** Components have leads that go through holes in the board. - **Surface Mount Technology (SMT):** Components are soldered directly onto the surface (allowing for smaller devices). ---