How to Build a Simple Homemade LED Night Light for Under $5

Introduction

A homemade LED night light is an easy and inexpensive project that anyone can make in less than an hour. With just a few basic electronic components, I was able to build a simple night light that provides a soft glow in a dark room for less than $5 in materials. In this article, I will walk through the complete process of assembling this simple circuit and constructing the case to hold the electronics. Read on to learn how I built a cheap and easy homemade LED night light that functions just as well as ones sold in stores.

Parts and Tools Needed

To build the LED night light, you will need the following materials:

• 5mm white LED (light emitting diode) - $0.25
• 220 ohm resistor - $0.10
• CR2032 3V lithium coin cell battery - $2.00
• CR2032 battery holder - $0.50
• Toggle switch - $0.50
• Short piece of 22 gauge hookup wire
• Hot glue gun
• Soldering iron and solder
• Wire cutters
• Cardstock, thin cardboard, or plastic to construct case

The total cost of these components purchased separately is under $5. Many of these parts can be salvaged from old electronics or purchased in packs for very cheap.

The tools needed for construction are:

• Soldering iron and solder
• Wire cutters/strippers
• Hot glue gun
• Scissors
• Marker or pen
• Ruler

Circuit Diagram

The circuit for this simple LED night light is very straightforward, requiring just a few components connected in series:

I will solder the resistor, LED, switch, and battery holder together in this configuration to control the light.

Constructing the Circuit

Follow these steps to assemble the circuit:

Step 1: Solder Resistor and LED

1. Cut two 1.5" pieces of hookup wire. I will use red for positive and black for ground.
2. Strip 1/4" insulation from each end.
3. Solder the 220 ohm resistor to the positive lead (red wire) of the LED.
4. Solder the negative lead (longer leg) of the LED to the black wire.

Step 2: Solder the Battery Holder and Switch

1. Cut two more wires about 3" long, one red and one black.
2. Solder the red wire to one terminal on the battery holder.
3. Solder the black wire to the second terminal.
4. Solder the toggle switch between the red wire from the battery holder and the rest of the circuit.

When complete, you should have a working circuit like the diagram!

Building the Night Light Case

To build the outer casing, follow these steps:

1. Cut a rectangle of material (cardstock, plastic, etc) to desired size. I cut mine 3" x 2".
2. Trace the battery holder and switch onto the material. Cut holes slightly smaller.
3. Glue the battery holder and switch into the holes cut for each component.
4. Glue the LED onto the front of the case, protruding slightly from the edge.
5. Hot glue the soldered connections and wires to the inside of the case. Avoid hot glue on the switch or battery holder.
6. Let cool completely before handling. Insert CR2032 battery and turn on!

I used hot glue to affix the components since it is strong and sets fast. Epoxy or other adhesives could also be used. Make sure wires have some slack and are not being pulled on.

Using the Homemade Night Light

To operate the night light:

• Insert CR2032 battery with the positive (+) side facing up.
• Slide the toggle switch to the 'on' position. The LED will illuminate!
• Place the night light in any dark room and enjoy the soft glow.
• Turn off by flipping the switch to 'off'.

The LED will provide many hours of light from the long-lasting CR2032 lithium battery. Exact runtime will depend on the specific LED and battery used.

Change the battery as needed when the LED becomes noticeably dimmer. Unscrew the battery holder or gently pry open to replace the CR2032.

Customizing and Improving the Design

This simple circuit makes a great starting point for building your own custom LED night lights. Some ideas for enhancements include:

• Add more LEDs for brighter light
• Include resistors for each additional LED
• Power with AA or AAA batteries for longer runtime
• Use a compact 9V battery for more LEDs
• Add an integrated circuit or photoresistor to automate turn on/off
• Improve the case with acrylic, 3D printed parts, or other materials

With some basic electronics knowledge and creativity, the possibilities are endless! The skills learned from this project can be applied to making LED flashlights, glow lamps, or other useful illuminated gadgets.

Conclusion

Building your own battery-powered LED night light is a fun electronics project that can be constructed by beginners for less than $5. With an LED, resistor, switch, battery holder, wires, and simple case, I was able to make a simple homemade night light in under an hour. This useful low-cost light provides customizable soft illumination in any dark space. With the circuit diagram and construction steps provided, anyone can now build their own version of this handy LED night light!