# Difference Between Active and Passive Components in Electronics

## 🔋 Active Components

Active components are electronic devices that **can amplify signals**, **control current**, or **produce energy**. They require an external power source to function.

### Examples:
- **Transistors** – Amplify or switch electronic signals
- **Diodes** (including LEDs) – Allow current in one direction, used in rectification
- **Integrated Circuits (ICs)** – Contain multiple active and passive components

### Key Features:
- Require external power to operate
- Can **inject power** into a circuit
- Can **control the flow** of electricity
- Used for **amplification**, **signal processing**, and **switching**

---

## 🔌 Passive Components

Passive components cannot amplify or generate power. They only **respond to** the electrical signals applied to them.

### Examples:
- **Resistors** – Limit current flow
- **Capacitors** – Store and release energy as an electric field
- **Inductors** – Store energy in a magnetic field
- **Transformers** – Transfer energy between circuits via magnetic fields

### Key Features:
- Do **not require** external power to operate
- **Cannot amplify** signals
- Used for **filtering**, **energy storage**, **tuning**, and **impedance matching**

---

## ⚖️ Quick Analogy

- **Passive Component**: Like a **valve or container** — it regulates or stores energy.
- **Active Component**: Like a **pump** — it can **add energy** and control the system dynamically.

---
# 🔋 10 Active Electronic Components

![Active Components](./active_components_symbols.png)

# 🔌 10 Passive Electronic Components
![Passive Components](./passive_components_symbols.png)

------
# 🔁 Use in a Timer Circuit

# 🔧 555 Timer LED Blinker Circuit (Astable Mode)

This project uses a 555 timer IC in **astable mode** to blink an LED on and off at a regular interval.

---

## 🧰 Required Components

| Component       | Value            | Quantity |
|----------------|------------------|----------|
| 555 Timer IC    | NE555            | 1        |
| Resistor R1     | 10 kΩ            | 1        |
| Resistor R2     | 10 kΩ            | 1        |
| Resistor R3     | 470 Ω            | 1        |
| Capacitor C1    | 10 µF (electrolytic) | 1    |
| LED             | Any color        | 1        |
| Power Supply    | 5V – 9V DC       | 1        |
| Breadboard + jumper wires | —      | —        |

---

## 🔁 How It Works

The 555 timer is configured in **astable mode**, which means it continuously switches between high and low states:

- The **output pin (pin 3)** alternates between HIGH and LOW.
- This causes the **LED to blink** on and off.
- The **timing interval** is determined by **R1**, **R2**, and **C1**.

---

## ⏱️ Blinking Frequency Formula

To change the blink rate:

T = 0.693 × (R1 + 2×R2) × C1


Where:
- `T` is the period in seconds
- `R1`, `R2` in ohms
- `C1` in farads

---

## 🔌 Circuit Schematic

![555 Timer LED Blink Circuit](./555_blink_circuit.png)

---

## ✅ Assembly Tips

- Ensure **pin 1** is connected to **GND**
- **Pin 8** goes to **Vcc**
- Make sure the **capacitor polarity** is correct (− side to GND)
- Use a **current-limiting resistor (R3)** with the LED to prevent damage

---

This is a perfect beginner project to understand **timers**, **oscillation**, and **basic LED control**. 

### Resources:

https://elonics.org/adjustable-led-flasher-using-555-timer/