Iphone charging...

Hello, my name is Martin
I have a very big problem with a 5v usb boost circuit. When i connect the circuit to the power, the led lights up, but no power... to iphones... everything else works, just not iphones. i already tried shorting the data ports with the 5v pin, AND THAT USED TO WORK, but not now!!!??

PLEASE HELP

I have now tried with adding some resistors to data+ and minus, still nothing

HELP!!!

0 shabaz over 11 years ago in reply to e14 Contributor

What are you powering that circuit with?
A couple of AA batteries? It will take a long time to charge your phone if so.
The resistors connect to the USB D+ and D- lines and to the 5V and 0V connections. In the link that Petri showed, the USB connector is shown on the right (i.e. corresponds to the USB connector on your board), and the two center pins there are designated USB D+ and D-. The top wire connection in that diagram is +5V and the bottom wire is 0V.
Google may have some better annotated diagrams, but the connections will be similar. Without the resistors, expect it not to work or to charge slowly.
Cancel
Vote Up +1 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

Thanks for the answers btw, but now i need more xD, while waiting for the resistors i tried shorting the data+ and data- just by connecting the two, and the phone charged! but... not really, since the icon was there, but the percentage wasnt going up, but down xD, is this because of the resistors i need? and also, what part of the 5v boost converter do i connect my resistors to? the regulator? capacitor (assuming that's the round black thing)? xD
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

Resistors can be what ever wattage, there's almost none current draw. I can't give you pictures from my ipod charger, it was gone by mistake when i sold my car. Now i only have a linear 7805 reg. in a piece of veroboard with some resistors and a ridiculously big heatsink, because ipod acts as a lithium battery when charging and pulls supply down to cell voltage, and so 7805 dissipates so much heat. Good thing is that it starts to cool down as battery gets charged.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

also the resistors i assume can be 1/4 watt?
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

Allright, ill hop over and order some 33k and 22k resistors i guess can you by any chance give me a pic of that selfmade ipod charger?
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

You could try that.
My self made ipod charger is done like that.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

But can the resistors just be placed loosely under the board? or what are you sugggesting?
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

Exactly. iphone charges only when d+ and d- are pulled to about 2.7v. I cannot exactly remember if those voltages are absolutely correct.
Normal USB charger just won't work for that reason.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago in reply to e14 Contributor

Im not sure if i understood correctly. This picture shows the device i have, and what you're telling me, is that somewhere, i have to add 4 resistors?
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 e14 Contributor over 11 years ago

You need to make a resistor dividers to both D+ and D- lines: http://cdn.instructables.com/FOF/IG95/GTLRHJWG/FOFIG95GTLRHJWG.LARGE.jpg
Cancel
Vote Up +1 Vote Down

Sign in to reply

Verify Answer

Cancel