Electronic components are the building blocks of all modern technology. They can be broadly categorized into **Passive**, **Active**, and **Electromechanical** components. --- ### 1. Passive Components These components do not require an external power source to function and cannot amplify a signal. They primarily store or dissipate energy. | Component | Symbol | Primary Function | Common Use Case | | :--- | :---: | :--- | :--- | | **Resistor** | R | Limits the flow of electrical current. | Adjusting signal levels, voltage division. | | **Capacitor** | C | Stores energy in an electric field. | Filtering noise, smoothing power supplies. | | **Inductor** | L | Stores energy in a magnetic field. | Radio frequency (RF) tuning, chokes. | --- ### 2. Active Components Active components rely on a source of power and can manipulate the flow of electricity to amplify signals or perform switching operations. * **Diodes:** Allow current to flow in only one direction. * *LED (Light Emitting Diode):* Converts electrical energy into light. * *Zener Diode:* Allows current to flow backward when a specific voltage is reached. * **Transistors:** The "brain" of circuits. They act as switches or amplifiers. * *BJT (Bipolar Junction Transistor)* * *MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor)* * **Integrated Circuits (ICs):** Thousands or millions of resistors and transistors packed into a single small silicon chip (e.g., Microprocessors, Op-Amps). --- ### 3. Electromechanical & Protection These parts bridge the gap between electrical signals and physical movement or protect the circuit from damage. * **Relays:** An electrically operated switch that uses an electromagnet to open or close contacts. * **Switches:** Manually interrupt or divert the flow of current. * **Fuses:** Protective devices that melt and break the circuit if the current becomes too high. --- ### Simple Circuit Code Example If you are using a microcontroller (like an Arduino) to control these parts, the code might look like this: ```cpp void setup() { pinMode(13, OUTPUT); // Set pin 13 (connected to an LED/Resistor) as output } void loop() { digitalWrite(13, HIGH); // Turn the LED on (Active state) delay(1000); // Wait for 1 second digitalWrite(13, LOW); // Turn the LED off delay(1000); // Wait for 1 second } ```