Introduction: Portable USB Charger (Version 2.0)
The project name says it all. It is a device that will charge things like Ipods, PDAs, other other devices that plugs into a USB to charge.
Step 1: Supplies
The parts needed for this project are all in the second picture.
You will require:
LM or MC 7805 +5VDC Voltage Regulator
Type-A Female USB Port
100 UF Electrolytic Capacitor 10-50v
0.1-0.5 UF Capacitor 6-50v (any type would do)
150-160 ohm Resistor (optional)
9V Battery clip
2.2V 20mA LED color of your choice (optional)
Unprinted circuit board
ON/OFF Switch (optional)
These parts can be easily purchased at your local electronic store, like Radio Shack. Or you can buy them online at:
100 uF Capacitor:
0.1 uF Capacitor:
Step 2: The Circuit Board (Simple Way)
The following picture shows the prepared PCB before putting in the necessary components.
What your looking at is the underside of a PCB with the copper foil facing you.
The gray line represent the location where the cut is to be made. Make sure that the 3 sections are electrically isolated (do not conduct to each other). If you have a dremel tool, you can score the copper cladding with a cutting wheel.
The black dots are the locations where holes are to be drilled.
Step 3: Attching the Components
Watch the polarity when putting in the components, especially the regulator, or it will get very hot and burn out.
*BEFORE plugging in your USB device to this charger, test the charger's output using a multimeter. Hookup the 9-volt battery and measure voltage output, it should be between 4.8-volts to 5.2 volts.
*If the black light comes on when you plug the iPod into the charger, that means the charger is working correctly, and if the black light doesn't come on after 3 seconds, remove the iPod from the charger immediately, and recheck your charger for shorting or incorrect polarity.
*If you double checked the output and still no luck, try attaching a resistor bank described in the comments below to the data lines.
Step 4: The Printed Circuit Board
The first picture is the circuit that is to be etched onto the PCB, the second picture shows where everything should go.
*Your looking at the side with the copper foil, so watch the polarity when putting in the components
Step 5: Printed Circuit With LED
This design incorporates a LED which will be lit when the device is turned on.
Step 6: Adding the Switch
Add a switch to this circuit is very simple, it'll save a lot of battery when you turn it off than just leaving it on idle. You can attach the switch anywhere BEFORE the capacitor (if you did not use a capacitor, then before the 7805).
Step 7: Done!
Now that you've finished building your own USB charger, all you have left to do is to put it in a nice box and show it off to your friends!