Simple IPod USB Charger




Posted in TechnologyUsb

Introduction: Simple IPod USB Charger

In this instructable, I will show you how to build a simple iPod charger! It's easy to make and modify, and is built to charge as fast as an official Apple USB charger.

Before we start, here's a little note:
DISCLAIMER: I'm not responsible for any damage of any kind to humans, materials, etc. by the use
and construction of this device. By using this device, you must agree to this condition. Otherwise, you
musn't use this device.

Sorry for some bad pictures, but they seem to went through a pixelation filter while uploading. You can see the original pictures by clicking the "i" in the top left corner of the picture.
Also, sorry for my bad English.

Feel free to comment or to pose questions!

Are you ready? Let's get started!

EDIT: added pcb in Eagle format.

Step 1: The Things You Will Need

To make this charger, you need this (common available) components:
-a 7805 voltage regulator
-a 1000µF, 35V electrolytic capacitor
-a 4.7µF, 15V electrolytic capacitor
 -2* 100nF capacitors
 -2* 5k (multiturn) trimmers
 -a USB connector, type A, female; or you can demolish an old USB cable
-a power supply that can provide at least 7.5V, and 1200mA
-a DC jack
-sticky, rubber feet
-a prototyping board
-solder: use 60/40, raisin core solder
-a 5K/W or better heatsink with M3 mounting bolts
-silicon cooling paste

And this tools:
-a soldering iron
-a sponge (to clean your soldering iron)
-diagonal cutters
-tweezers may be handy
-a iron saw
-a basic range of screwdrivers
-a screw or a drill
-a solder sucker or desoldering braid
-a basic multimeter that can measure resistance, and DC-voltage

You will also need this skills:
-you must know how to solder, if not check this video:
-basic electronic skills
-you must know how to use your multimeter

Step 2: The Design

The charger is based on a 7805 voltage regulator. We use an adaptor to power the regulator with 7V or more, because it needs around 2V more than it's output voltage. The capacitors are used to smoothen the input and output voltage. The 2 trimmers at the USB connector are used to tell the device that it can charge at a 1A charge rate. I will tell more about adjusting them in another step.

Below, you will find the American and European version of the scheme.
I also added the board for both versions (it's universal). Feel free to post comments to make the board more effective!

Step 3: Preparing the Board

You don't need the entire board, that would be a waste off materials and money!
We will saw-off the piece that we need. To do that, bolt down your 7805 loosly to your heatsink. Don't apply cooling paste yet! When you've done that, place all your components on the pcb. When you've done that, take a picture of your lay-out. Then, take a marker and draw a line around the piece that you need. After that, take off the components, and saw your board.

Step 4: Prepare the 7805

Now, apply a thin layer of cooling paste on the 7805. Spread it out, and bolt down the 7805 thight.

Step 5: Soldering Part 1

Now solder on the components that fit through the holes in the board. Clip off their wires, but don't connect them yet.

Step 6: Solder the Harder Components

We've now 3 components left: the second trimmer, the USB connector, and the DC-jack. They require an extra step.

For the trimmer and the USB connector, we need bigger holes. You can make them bigger by drilling a hole, or by using a screw. If you plan on using the screw, you need to take a screw with a sharp tip. Put it in the hole you've marked, and screw it in until you can see the pins will fit through the copper side. Make sure there's a bit of copper left around the hole, so you're able to solder the components. If you're ready with that, solder the trimmer, and the USB connector. You may need to bend the pins of the USB connector a little.

The DC-jack has 3 connections: 1 is going to the core of your adapter's plug, the 2 other connections are going to the side of it. Take your multimeter and measure the polarity of your adapter. Then, solder wires in the correct colors to the jack. In the pictures, I've used an adapter with a positive core, and a negative side. When you've soldered the wires to the jack, solder them to the pcb.

Look at the pictures for the result.

Step 7: Connect Evrything

Now, connect everything according to the scheme. You can do this by putting a lot of solder on both pads, and than heating the pads, so they will merge. You may need to use some wires.
For the USB connections, look at the final picture. These are also the colors you need to use, if you use an old cable instead of a pcb connector.

Step 8: Adjusting and Testing

Now it's time for a first test! Connect your charger to your psu and measure the 7805's output voltage. This should be around 5V. If the 7805 is getting hot without any load on the USB connector: disconnect the psu and check for shorts!
Then measure the voltage on the USB pins:
-Vcc should be 5V
-D- should be 2.8V --> you can adjust the D- trimmer until you become 2.8V
-D+ should be 2V --> you can adjust the D+ trimmer until you become 2V
-GND should be 0V
-the 2 pins on the housing may not be connected to anything

Step 9: The Final Test!

Now, connect your iPod/iPhone to the charger. If it doesn't say it's charging within 2-5sec, immediately disconnect the iPod and recheck for shorts or wrong connections.

Normally you will now have a working charger that will work much faster than your pc does. Enjoy! If there's a problem that you can't solve, feel free to post a comment (with a link to hi-res pictures of both sides of the pcb)!



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    A couple Queshtons:

    1. Will this work with iDevices that need power through the data pins
    2. Is there enough current to charge an iPad. If not how can I make it able to charge a iPad... Schematic?

    6 replies

    1: They don't need power through the data pins, devices like the iPhone, iPad, iPod touch,... need a certain voltage on the data pins to tell how much current they may draw from the adapter (the 2 trimmers do that work).

    2: I don't know, but one of my friends has an iPad 2, so I will do some testing tomorrow and let you know if it works. Else, I will look at the official iPad charger to see how I need to improve the design.

    Should I post a picture of the side of the charger that has all the info on it amp, volt, current, etc.?

    No, thanks. I need to configure an iPad for one of my friends and he has given me the charger, cable,... to do that. I will post the results in a few hours.

    It works with the iPad 2, but it is a little bit overkill for the 7805. As in it gets REALLY hot!

    Then I would suggest using a better heatsink, or another variation on the 7805 like I said in the comments above.

    Thanks for your help!

    I've done some testing and the result is: it works with the iPad 2! (propably with the other iPads too).
    But, I think it charges a bit slower than the official charger, if you want to test/change this: cut an old usb cable in half and put it in the official charger, measure the voltage on the data pins (please tell me your results, I don't have any spare cables), adjust the 2 5k trimmers to the same voltages, use an adapter that can supply at +/- 2.5 Amps and replace the 7805 with a 78S05 or a 78T05 (you also need better cooling and I highly reccomend using thicker cables).

    what cooling paste?
    It should be silicone paste...

    1 reply

    Isn't that the same? I don't have many experience with it, but on my tube it sais: "silicone grease" when I asked for cooling paste (it works fine).

    It should work with the iPod Touch 4G. I've used the original discovery of Ladyada when she disassembled an official  Apple charger. ( ) I wanted to make a MintyBoost! from their site, and found that page, so I created this charger (until I've the money for the MintyBoost! kit).

    thank-you that was one of the most informative reply's i've ever gotten on here and 5*'s for the instructable.

    You're welcome! (Thank-you for rating!)

    Do you have any availiable PCB files for this project? If so where can i find them. I am also subscribing to you here on instructables and hope to see more fantastic electronics projects like this one.

    P.S. ONE FINAL QUESTION (.........for now ) Where did you find such a big heatsink i've been looking for ones like thoughs for a while now and havent found a single one anywhere. Please let me know. Thank You

    I can create a pcb (eagle) if you want that.

    I'm using a Velleman heatsink, type ML97/1.5 dimentions: 42x38x25mm, thermal resistance: 5K/W It's a bit overkill with my new adapter, but it's designed to operate at 12V, 1A, roomtemp: 35°c or below, and still keep the 7805 below 115°c (it can handle 125°c).
    I couldn't find a company that sells them to USA, but if you are European, you can order them from Conrad. You can also try Ebay.