iPod thieves will not be charged

Apple patent filing describes method for disabling device chargers

Simon Aughton
25 Jul 2007

Apple has invented a novel method of disabling stolen iPods - by preventing them from charging.

The company has filed a patent for a technology that recognises when a device is plugged into an unauthorised computer and, if it is, prevents any further charging.

Every portable gadget with a rechargeable battery has a charging circuit that recognises when the external mains charger has been plugged in. It then manages the transfer of current to the battery. Apple's patent suggests that by attaching a "guardian circuit" to the charging circuit, it would be possible to block the charging process.

When a device is plugged into an unauthorised computer, software would compare a security code in the device to a code buried in the software in the computer. Apple already employs a similar technology to "pair" iPods to iTunes running on a specific Mac or PC. If the codes do not match, then the guardian circuit could be triggered to prevent any further charging.

"For devices that are mainly powered by a rechargeable-power-supply (eg. music-players, phones, Personal Digital Assistants), disabling the recharger effectively renders the device inoperable when the power of the main power-supply has run out," Apple notes in the filing. "As such, disabling the recharger should serve as a deterrent to theft."

Now if it could also send the owner an email, telling them where it might be found, that would be useful.

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