A simple and customizable USB-powered LED lamp project for electronics enthusiasts, students, and makers. This guide walks you through building a USB-powered lamp from scratch using basic electronic components. The lamp runs on the standard 5V supplied by any USB port (e.g., from a computer, power bank, or wall adapter), making it a portable and efficient lighting solution. Whether you're just getting started with electronics or looking to add a small lighting solution to your workspace, this project provides a rewarding and educational experience with minimal cost and effort.
| Component | Quantity | Notes |
|---|---|---|
| USB Type-A Male Plug | 1 | Or a USB cable for easier connection |
| LED | 1 | Choose based on your color preference |
| Resistor | 1 | See table below for suggested values |
| Switch | Optional | For manual control |
| Heat Shrink Tubing | Optional | For insulation and finish |
| Soldering Kit | - | For permanent assembly |
| Breadboard/Wires | Optional | For testing before soldering |
Circuit Diagram
Circuit Schematic
To calculate the appropriate resistor value:
Where:
-
$$V_{USB}$$ = Supply voltage from the USB port (5V) -
$$V_f$$ = Forward voltage of the LED (depends on color) -
$$I_f$$ = Forward current (typically 5–20mA)
Different LED colors have different forward voltage drops (
| LED Color | Approximate Vf (V) | Suggested Resistor (Ω) @15mA | Acceptable Range (Ω) @5–20mA |
|---|---|---|---|
| Red | 2.0 | 200 | 150 – 600 |
| Green | 2.2 | 180 | 140 – 560 |
| Yellow | 2.2 | 180 | 140 – 560 |
| Blue | 3.2 | 120 | 90 – 360 |
| White | 3.2 | 120 | 90 – 360 |
ℹ️ Use the next higher standard resistor if the calculated value is not available (e.g., use 200Ω instead of 197Ω).
Simulate and test the circuit online using Tinkercad.
- USB 2.0 port provides up to 500mA
- This circuit typically draws 15–20mA
- You can safely power one LED with plenty of margin
ℹ️ You can connect multiple LEDs in parallel, but each must have its own resistor to ensure proper current limiting.
⚠️ Never connect LEDs directly in parallel without individual resistors, and keep total current below USB limits (<500 mA).
Prototype Snapshot 1
Prototype Snapshot 2
Feel free to fork the project and open pull requests. Bug reports, enhancements, and photos of your builds are welcome!