Modify old dock to charge new ipod

Thread Starter

sky12

Joined Feb 21, 2010
5
I came across an old thread: http://forum.allaboutcircuits.com/showthread.php?t=17729 (I hope a link is ok) that listed some details about what I want to do to my dock, but it was too old to accept replies and I just wanted to clarify what I have read so I don't mess anything expensive up.

So, I need to put a 7805 regulator between the 9v wire coming off the board and connect it to pins 23 and 15 on the ipod dock. I also need to use a heatsink.
Then I need to tie pins 25 and 27 together with a 10k ohm resistor.
This is all assuming my dock has similar innards to the above docks as I haven't opened it yet.

Some questions:

Does the above sound correct?

Is the heatsink TO-220 heatsink Radioshack# 276-1363 or the TO-220/TO-202 Aluminum heatsink Radioshack# 276-1368?

My dock is also a Klipsch like the last post in the above thread, but a roomgroove instead of an igroove and it worries me a little that the current did what it did. Does anyone know why this happened? I don't really understand the "5V zener and 100uF cap across the 5V rail and ground" part of the post, but do you think I will need to add this?

Sorry for the long post, but thanks in advance for the help!
 

retched

Joined Dec 5, 2009
5,207
What is the name and model number of you device? The pinouts are most likely different between your and theirs. So, gotta start from square one. Once we find what make and model you have, get the pinouts and go from there.
 

john-o

Joined Feb 24, 2010
2
I am trying to mod my Klipsch iGroove HG to charge my iPod Touch. I think it should not be too difficult and have seen the previous post on this topic (now closed). My problem at the moment is that I can't find a way to open the case. I have undone the two screws either side of the dock connector but that only loosened the connector. I have looked under the rubber feet and the label for hidden screws but nothing found. Any suggestions? The Klipsch distributors in the UK were not able to provide any help.

John
 

Thread Starter

sky12

Joined Feb 21, 2010
5
I believe the pinouts on the dock are universal so they should all be the same, but after the first generation ipod touch, iphone, etc, they changed the charging method to the usb pin instead of firewire and the older docks were not setup to charge from the usb pin. This is where my question is, applying power to the usb pin so it will charge the newer ipod touch.
 

john-o

Joined Feb 24, 2010
2
You need to emulate some bits of the standard Apple USB lead with dock connector. I have chopped off the female socket and a bit of lead from a male female USB extender. I have wired it up so that each of the 2 data pins in the middle of the USB connector is connected through a 47K resistor to both the positive and negative pins which are on the outside. (So it looks like 4 resistors arranged in a square with positive an negative attached to opposite corners and the two data leads connected to the other 2 corners). If I plug in the standard Apple lead's USB plug into this and feed the positive and negative leads at the other end with 5volts (make sure it has the right polarity) then the IPT charges. So you need to replicate this in the dock connector. It needs 0v and 5v and some resistors to hold the data pins at half volts.

Have you managed to open it up yet?
 

Thread Starter

sky12

Joined Feb 21, 2010
5
John-O
I haven't taken it apart, but it looks very easy with the roomgroove. I don't know if you've seen a Klipsch Roomgroove, but there is a large black material speaker grill on the front that can be easily taken off (there are no screws holding it on, it is just a press fit) That exposes the gears for the dock and tons of screws (if I remember right more than ten screws). On your dock there may be plastic clips holding it together. I have taken several things apart before and I am usually surprised if I don't find at least one clip holding something together. They would be around the "seam" where the two pieces come together and you can usually press a fine screwdriver in the seam to release them, but be very careful as you could easily crack the plastic or press the screwdriver too far and hit something important on the inside. Before you look for clips that may or may not be there see if the speaker grill on your model is just a press fit. If it is it should come off pretty easily, but don't force it if it doesn't want to come off as it may be attached completely different than my model.
Hope I helped
 
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