This simple instructable will show you how to make a wall charger that can charge / operate any USB device, including iPhones and iPods.
Most DIY chargers can not charge iPods and iPhones. This one can, however!
This charger takes input from both a 9v battery and a size N DC Coaxial plug.
A wall charger or car charger with the right voltage and amperage can be modified to have a size N DC Coax plug with a cable coming out of it.
Most of the pictures of the charger itself are on the last page (Step 7).
Step 1: Materials
5V regulator and SMALL Heatsink: I used Radio Shack part: http://www.radioshack.com/search/index.jsp?kwCatId=&kw=5v%20regulator&origkw=5V%20regulator&sr=1
Resistors: 22 Kohm (1), 27 Kohm (2), 39 Kohm (1).
I used Radio Shack part: http://www.radioshack.com/product/index.jsp?productId=2062306#
DPDT Toggle Switch: This will be used to switch between the battery and the DC Coax Jack.
USB Extension Cable: Any cable with a type A Female USB port will work.
AC / DC Wall Transformer: Try to get one with <10 volts and equal to or less than 1.5 amps. The regulator will overheat and / or blow if you put more than 1.5 amps into it.
Cigarette Lighter Car Adapter: 12V dc
Size N DC Power Plug (2): With wires attatched.
Size N DC Power Jack (1): Panel Mount with solder leads.
Prototyping Board: I used Radio Shack Part: http://www.radioshack.com/product/index.jsp?productId=2104052
Project Box: Whatever kind you need to fit the components inside
Wire: I used a mix of 22 gauge solid and stranded wire.
Heat Shrink Tubing: An assortment of sizes would help.
9V battery and 9V Battery Clip
Cable Stress Relief Joint That Fits The USB Cable: I cannot stress (No pun intended) how important this is. If this fails then the USB cable solder joints can be damaged
Soldering Iron with Solder
Third Hand (Optional, but would be very useful)
Step 2: Step 1: Understand the Layout and Circuit
To find the pins of the USB Cable, cut and strip the end with the female port, leaving about 2 inches of wire on the end. The different colored cables are labeled as follows:
Red: + 5V
White: Data +
Green: Data -
Step 3: Step 3: Solder the Components
My circuit after soldering is shown in the picture. Unfortunately, I put the circuit board in the case before I took the picture.
Step 4: Mount the PCB in the Case
Use screws to mount the circuit board.
My project box had PCB screw mounts already on it, but I had to cut them off, move them, and glue them back down.
Also, cut out a notch that fits the stress relief joint, glue it in, and put the cable in.
Step 5: Modify the Transformers
1. Find the crack in the transformer and pound at with a thin screwdriver and a hammer untill it cracks along the line.
2. Slowly cut the crack in the transformer with a utility knife.
3. Find the crack in the transformer and cut it open with a hacksaw
Find the + and - terminals of the transformer and unsolder the wires that were there. Resolder the wires from your DC Male plug onto the same points. Make sure you have the polarity correct!
Test the polarity with a multimeter, and if all is well epoxy the case of your transformers shut.
You can skip this step if your transformer already has the size N DC plug on it.
Step 6: Mount and Solder the Switch and DC Jack.
Mount the DPDT switch and the DC coax plug in a reasonable location. Then solder them to the circuit board using the schematic below.
Step 7: Finish
Another important factor to consider when making this is to make sure that the transformer has less than 25 volts and less than 1.5 amps.
I added some stickers for fun. It'll get some funny looks on the bus or the plane.