modify a cheap usb charger to feed an ipod, iphone or samsung galaxy
So I bought a very cheap one but it never worked.
The IPod does not like it once connected and does not want to charge.
I let it sit in the drawer and forget it because it was so cheap.
I stumbled upon this very good article a while ago: they described how they produced a battery powered USB charger.
After reading that article, I took the cheap USB charger and decided to modify it.
This will be a very, very easy revision and I think anyone with a soldering iron can do that.
The USB connector has 4 pins: V, D-, D+, GND.
The V pin with GND gives 5 v for limiting the phone; while the D-
D pin for communication.
Old USB electronics don\'t care about D /-
As long as the other two give nutrition, the pin is OK.
Today, the iPhone expects a certain voltage on both pins to determine how much current is absorbed from the charger. Putting a 2.
The IPhone will absorb a voltage of 0 v on about 500 mA of the two pins, while 2. 8 V on D-and 2.
It absorbs about 1000 mA on D.
I hope the same behavior can be observed on my iPod.
There are two configurations on the image.
As you can see, the required voltage can be obtained using the right few resistors.
Obviously the 1000 mA configuration will be better if you want your phone to charge faster, but your power supply may not support that much current.
To see if my data pin for USB charging is under the wrong voltage, I opened the plastic case with a hobby knife.
The case was stuck together so I had to take it apart.
However, the top of the car USB chargher is screwed.
I\'m happy to find the fuse between the two: My iPod should be safe!
As you can see on the picture, the data pin is floating, which is why my iPod doesn\'t want to charge.
Specifications for stickers on the item, when the car charger does not exceed 500 mA, the plug on the wall cannot provide more than 1000 mA.
I decided to stick to 500 mA for both of them.
I need a few resistors that can give me a 2. 0 V out of 5. 0 V.
I chose: 220 ohm and 330 Ohm.
The two pins should be at the same voltage, so only 2 pairs of resistors are required.
I used my Dremel to drill 4 holes in the wall stopper board for my resistor.
To make it easier to weld, the holes are close to the USB pin.
The car charger has a lot of space so I don\'t need to drill holes.
I then added a new resistor to the board. I short-
Connect the data pins with a little solder because I want them all at 2. 0 V.
Unfortunately, as you can see on the picture of the car charger, I am not a very skilled claimant.
After the welding was done, I checked all the connections with a multimeter.
I then plug in the charger to check if the tension is good.
I managed to get about 2.
Both of them have a v.
This is a very dangerous step because I have them powered on and found out that touching them can cause damage.
I then tested the charger on my iPod, Samsung Galaxy and some friends iPod.
They seem to charge well and have no complaints.
However, when charging the Samsung Galaxy, the charger becomes very hot.
I\'m not sure if it\'s good because I \'ve never used it without my \"fix.
I should measure the current consumed by Galaxy to see if it is in the parameters of the charger.
My conclusion is: it works!