# 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**
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## 🔌 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**
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## ⚖️ 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.
This project uses a 555 timer IC in **astable mode** to blink an LED on and off at a regular interval.
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## 🧰 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 | — | — |
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## 🔁 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**.
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## ⏱️ 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
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## 🔌 Circuit Schematic
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## ✅ 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
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This is a perfect beginner project to understand **timers**, **oscillation**, and **basic LED control**. Let me know if you'd like to simulate this or turn it into a PCB design!
