To build a circuit with **5 LEDs**, you need to understand several key electronic components and the two primary ways to wire them. --- ## 1. Core Components | Component | Purpose | Key Identification | | :--- | :--- | :--- | | **LED (Light Emitting Diode)** | Converts electricity into light. | Long leg = Anode (+), Short leg = Cathode (-) | | **Resistor** | Limits current to prevent burning out the LEDs. | Marked with colored bands (e.g., 220Ω or 330Ω) | | **Power Source** | Provides voltage (V). | Battery (9V, AA) or Microcontroller (Arduino 5V) | | **Breadboard** | A platform to connect parts without soldering. | Internal metal strips connect holes in rows/columns | | **Jumper Wires** | Connects components to each other. | Male-to-Male or Male-to-Female | --- ## 2. Wiring Configurations When connecting 5 LEDs, you have two main options depending on your power source voltage. ### Option A: Parallel Circuit (Recommended for 5V) In a parallel circuit, each LED has its own path to the power source. This is the safest way to ensure all LEDs shine with the same brightness. * **Setup:** Connect the positive legs (anodes) of all 5 LEDs to the positive rail, each with its own **resistor**. * **Formula:** $R = (V_{source} - V_{forward}) / I$ ### Option B: Series Circuit (Recommended for higher voltage) In a series circuit, the LEDs are connected in a single chain (Positive $\rightarrow$ Negative $\rightarrow$ Positive). * **Requirement:** The power source must have a higher voltage than the sum of the LEDs' forward voltages. * **Example:** If each LED needs 2V, 5 LEDs in series require at least 10V. --- ## 3. Calculation Example (for a 9V Battery) If you want to run 5 LEDs in parallel using a 9V battery: | Parameter | Typical Value | | :--- | :--- | | **Input Voltage** | 9V | | **LED Forward Voltage** | 2.0V (Standard Red LED) | | **Target Current** | 20mA (0.02A) | | **Resistor Needed** | **350Ω** (Use 330Ω or 470Ω as standard) | --- ### Safety Tips 1. **Never connect an LED directly to a battery:** Without a resistor, the LED will draw too much current and pop/burn instantly. 2. **Check Polarity:** LEDs only allow electricity to flow in one direction. If it doesn't light up, try flipping it around. 3. **Heat:** If your resistors feel very hot to the touch, you may need a resistor with a higher wattage rating or higher resistance value.