[mrdelayer]

On my desk sits an old, broken, out-of-warranty, fourth-generation 20 GB iPod. It has a broken screen and a destroyed hard drive. (The broken screen resulted from me attempting to open it to retrieve the destroyed hard drive to find out what sort of replacement I'd need. And that general curiosity I have when it comes to finding out what's inside of broken things. For the record, Apple wants around $250, plus tax and shipping both ways, to replace it.)

I've been considering building a Cmoy amp lately, and today I glanced at the broken iPod today and thought, "Wouldn't that make an interesting case?" Has this been done before? Any suggestions? I'll probably need to find some other sort of batteries, as I don't think this iPod is big enough depth-wise to hold a 9V battery.

I was thinking, I could keep the dock connector and headphone jack; use the dock connector for input (using one of those handy adaptors I've seen used here for output from an iPod to an amp) and the headphone jack for (duh) output. Keep in mind this is just an idea. I may just end up using the standard Altoids or whatever mint case (I think I have a tin of Penguin Reds around here somewhere that would also be suitable), especially if power becomes such an issue.

 

[hugz]

Is it possible to use the ipod battery at all? I dunno much about the ipod, nor what voltage its battery is, but that'd be serrrrriously cool

 

[mrdelayer]

The [4G] iPod's battery is 3.7 V, quite a bit less than what is needed for the Cmoy.

 

[Polaris111688]

Use a DC-DC converter.

 

[threepointone]

be careful with li-ions. you still need protection circuitry. it might be safer to borrow some of it from the iPod, assumign the protection circuitry is still alive

 

[splaz]

CMOS op-amp, or possible add in another battery if there's space in series ?

 

[ATAT]

keep the main board, tap the power line for output stage (output opamp) on your ipod.. you could also tap the I/O and get by without casework.

NEVER bypass the protection circuitry of the ipod.. thats just a horrible idea. unless you love lithium fires.

 

[mrdelayer]

Okay, I'm thinking it might not be the safest idea to try to use the iPod's existing battery, considering my knowledge and experience with electronics, while not nonexistent, isn't quite enough to be messing with things like batteries. Any other suggestions as to how to power this thing?

 

[ATAT]

Gut out the ipod, put AAA and a simple charging circuit.

 

[mrdelayer]

Would you happen to have an example of a charging circuit? I probably wouldn't do this at this moment, seeing as this would be my first cmoy and I don't really want to deviate the design a whole lot. This was really just an idea I had, but once I get the hang of building them I might consider doing it.

 

[splaz]

Well trickle chargers are easy enough, I'll dig one up later as someone made a tiny little one from an LM317LZ and a few diodes and resistors.

Fast chargers, are a little harder but you can buy ICs purely for this purpose, just need some external circuitry for the charge output, a resistor voltage divider and maybe a thermistor.