Palm Touchstone

With the Palm Pre, Palm is also releasing the “Touchstone.” The Touchstone is a charging device that uses Electromagnetic Induction to wirelessly charge the Palm Pre.

Using the Touchstone

You can’t use your Palm Pre’s original battery hardware with the Touchstone ($49.99), you have to also get the Palm Pre Replacement Back Cover ($19.99), or just simply get the whole kit for an extra penny: $69.99. The touchstone plugs into the charger that came with your Palm Pre, so if you’re planning on making your Touchstone a secondary charging location, you’ll have to buy an additional international power charger as well ($39.99).

The Touchstone magnetically locks your Palm Pre into place after you’ve changed the replacement backing, and charges your Palm Pre without wires while it sits there.

Electromagnetic Induction Technology

Although Palm’s Touchstone has made waves in the mobile arena with its novelty wireless charging capabilities, this method of charging isn’t new. If you own one of several electric toothbrushes that uses this technology for instance, you’ll remember that your brush does magically charge through the water-proof rubbery surface when you place it on the charging dock.

The technology was developed first in the 1800s by Michael Faraday when he noticed that the electromotive force (EMF) produced around a closed path is proportional to the rate of change of the magnetic flux through any surface bounded by that path. This simply means that whenever the magnetic flux in a closed circuit changes, electric current is produced.