Portable Solar Power

Electronics Project: Build a Solar Power Supply

Assembly Time: 2 hours depending on experience
Difficulty: Beginner
Designer: Braulio777

Solar Power Supply Solar power, a renewable, environmentally friendly resource, can help save you money and protect the planet. We have a great Solar Power Supply project based on a 6V Solar Cell. It's constructed with two voltage regulators, one of 5V and other of 3.3V. The project is integrated inside a plastic box and in its exterior side is mounted the Solar Cell and a selectable switch to decide between 5V and 3.3V.

Required tools and components:

Soldering iron
Wire strippers
Needle nose pliers
Drill and 1/4" drill bit
Double Sided Foam Tape
0.1µF 25 Volt 20% Ceramic Disc Capacitor
Low Dropout Regulator 3.3 Volt 1.5A
1/8 Heat Shrink Tubing, 4'
1/4 Heat Shrink Tubing, 4'
SPDT Toggle Switch
1µF 50 Volt 20% Radial Capacitor
Standard Regulator 5 Volt 1 Amp
ABS Plastic Enclosure for Arduino Board
Solar Panel 6 V DC 150mA
Arduino Uno Proto Shield (PCB only)
USB A Male to USB A Female 2.0 Cable

Start by making sure you have all required materials, tools and parts. Follow the circuit diagram below carefully in order to avoid errors.

Solar Power Supply Schematic

First install the voltage regulators. You can see the details of each regulator either +5V or +3.3V.

Next, drill a 1/4" hole in the plastic enclosure so that you can install the toggle switch (3.3V-none-5V). Install your selectable switch to decide between the two options.

Prepare the toggle switch by soldering a wire on each one of its pins. Though it's optional to use heat shrink tubing, it's important to note that the wires with white heat shrink tubing are going to be connected to the voltage regulators while the red will connect to the positive terminal of your solar cell.

Next, install the toggle switch by using the hole previously made in the bottom side of the plastic enclosure. Insert the prepared PCB. Connect the wires with white heat shrink tubing to the inputs of the voltage regulators and leave free the wire with red heat shrink tube to be connected later.

Toggle Switch

To install the solar cell, it's necessary to use the wire with red heat shrink tube. Place the tube between the wires with white heat shrink tubing. Before connecting the wire, cover the wires of the solar cell with black heat shrink tube of 1/4" Cover the positive terminal with heat shrink tube of 1/8".

To connect the negative terminal of the solar cell look for a ground to connect the black wire of the solar cell. To complete the connections of the solar cell it's necessary to move the heat shrink tubing previously placed and fixed with a hair dryer.

It's necessary to use the USB-A female to USB-A male cable and cut 1 foot of cable from the USB-A female connector. Remove the black plastic and the rest of material that covers the four wires into cable by cutting the white and green wires, leaving the red and black only to be utilized. Use the 1/4" heat shrink tube to protect the exposed metal of the cable previously cut.

Install the USB-A
To install the USB-A female cable, connect the red wire of this to the output of the voltage regulators and connect the black one to ground.

Set the Solar Cell

Solar Power Supply

After applying the solar cell, put foam-tape close to the toggle switch for writing the voltages. The select able switch will have two voltages written either 3.3V or 5V. You're ready to use your new solar cell power supply!

Warning! Working with electronics can be dangerous. Always use caution and follow all safety procedures. If you are uncertain of the dangers involved with a particular project be sure to seek assistance. Failure to follow safety procedures may result in injury or death.
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