Also everything I just said is somewhat misleading, this circuit for some reason works more like an external battery rather then charger. If someone could point out why Ipod's say charged when this is plugged in rather then charging please let me know and I will update accordingly.
On the last step at the bottom also tells you how to get the same USB plugs I use free.
*I was looking at the Minty Boost Instructable page and it said a 9v battery with a 5v regulator aren't efficient because the regulator gives off lots of energy as heat. I haven't calculated the efficiency of this circuit but it should be fairly efficient because the transistor, unlike the regulator, looses almost no energy as heat. If someone decides to calculate the efficiency please let me know what it is, I would like to know but will never get around to calculating it myself. Thanks.*
NPN circuit is on the last page.
Also this instructable may help get the Ipod to charge:
How to get your iPod to charge with your homemade charger.
Its about the data pins and uses 4 resistors.
Step 1: Parts
- 9v Battery
- 9v battery clip
- 2N4403 PNP transistor (Circuit can be modified for a NPN fairly easily)
- 5k variable resistor or trim pot (I used a trim pot because I had the right size lying around)
- 100 - 330 ohm resistor
- LED (color is up to you, I suggest green cause it looks more power, circuit working, good kind
of look to it, where as red looks like STOP! theres a problem! type of thing, if you know what I
- a ceramic or tantalum capacitor (last step I have a question about tantalum caps, Please
- a 6 to whatever volt 220uF cap (I used a 50v cap which is a little over kill)
- Female USB plug or other plug
- perf board or you can etch you own with copper clad
- soldering iron and stand (stands optional but handy)
- side snips
- a dremel or other tool to cut perf or copper clad board
Step 2: Circuit
Also the third picture is a board layout if you want to etch a custom board.
Also when using the electrolytic cap and if you use tantalum cap make sure polarity is correct, positive is the long lead, negative is the short lead.
Step 3: Solder
Step 4: Questions
Here is how to get the female USB plugs free, the same ones I have:
Look under connectors at SamTec, that's where I got mine. Click on Samples and put in:
in the part number box and change quantity to 5.
If you can't get to website from above then use this URL:
Then just copy paste:
into the item #1 box below the form
Don't forget to fill in all the information.