Steps 1–5: Teardown
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Palm Touchstone Charger Teardown
Introduction
In this teardown, we will show you the innards of Palm's slick induction based Touchstone Charging Kit for the Pre.
Teardown
Teardowns provide a look inside a device and should not be used as disassembly instructions.
Featured Guide
This guide has been found to be exceptionally cool by the iFixit staff.
Paginated Single Page Steps
Step 1
—
Teardown
The Palm Pre can be recharged in two fashions:
Wired Micro USB, included with the phone and rather lame.
Or the super-cool Touchstone wireless inductance charging system, which will set you back a measly $69.99
The Touchstone charger utilizes magnetic inductance, or electric current produced through a loop of wire in the presence of a magnetic field, to charge its internal battery wirelessly.
The beautifully designed packaging includes:
Touchstone charging dock.
Touchstone back cover.
User guides and warranty information.
Step 2
Weighing in at a portly 118 grams, the Touchstone dock makes a great paperweight.
And it's so pretty!
Palm has attached pretty chrome dots to show you which cable plugs in where.
The underside of the dock is nearly covered in a doughnut of foam tape. Don't stick it to a veneer table!
The AC adapter has a detachable plug, presumably allowing for connectivity in foreign countries.
Step 3
Side-by-side view of the Touchstone back and the standard Pre rear panel.
The Touchstone rear panel has a matte finish, probably to reduce visible wear from constant contact with the dock.
The outline of the induction loop (large circle) is visible on the inside of the Touchstone rear panel. The current produced by induction flows into the Pre via two gold plated pressure contacts.
The four small circles are magnets that align the Pre to the Touchstone dock, similar to the way Best Buy's iPod displays always align the iPod right side up.
Step 4
The inductor charging base assembly.
The new Palm Touchstone wireless charger works on the principle of resonant induction. When you move a magnetic field near a coil of wire, it induces a current in the wire.
Taking advantage of this principle, the Touchstone creates an electrical coupling between two coils of wire that are not physically connected. It does this with a primary coil of wire in the base unit which transmits energy to the secondary coil of wire in the phone via a magnetic field.
Step 5
The Touchstone rear panel includes a secondary induction coil.
The magnetic field generated by the base unit turns on and off rapidly, generating a magnetic pulse that is carefully tuned to the dimensions of the wire coil inside the phone. This oscillating magnetic field induces a current inside the phone, allowing the battery to be charged.
Similar technology is used to transmit power to some battery-operated toothbrushes, razors, etc.
This explanation is an oversimplification of a very specific field of electrical engineering.
You'll note that the location of the induction coil is in the center of the device, well away from the antennas that line the perimeter of the phone.
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That's not foam tape! That's the material that's based on gecko feet, the stuff you can mount even on glass without leaving a mark.
The "foam tape" might be the first implementation of carbon nanotubes technology that mimics the minute hairs that allow geckos to cling to vertical surfaces.
--http://www.sciencedaily.com/releases/200...
--http://www.nytimes.com/2005/08/30/scienc...
iFixit Staff
Blueness, can you give me a source for that information about the Touchstone's base? It certainly does grip nicely.
A link refering to palm saying the base would use that technology:
http://palmprefix.com/2009/02/11/palm-pre-touchstone-touched-me-a-review/
Also a link to VP of design mentioning the tech in a youtube linked interview at 2:25s :
http://www.youtube.com/watch?v=Ai6OM8ike...
I wonder how efficient this is compared to the normal charger - is it Energy Star rated?
Your wrong about the "foam tape". It isn't that new. It's Micro-Suction® (registered in 2003). It's still cool but not what "deeceefar2" says it is. Most importantly, clean it with scotch tape or a wet rag if it looses it's suction. It doesn't stick when wet.
http://corporate.inventables.com/Custome...
https://s3.amazonaws.com/inventables_tec...
I really like the charger kit with the magnetic. This palm pre touchstone charging kit is really useful and unique, it uses no wires to charge up the palm pre. I purchased it on this site.
http://www.msgdigital.com/productdetail....
Geeko tape is polyamide not carbon nano tubes. baesystems own the patent and rights to geeko tape. one of if not 'the' longest patent applications ever. something like over 170 pages.
How is the base held on? Rivets? Screws?
I have read that only the Pre USB cables wold work with this base, but it looks like with a little modification that can be changed.
iFixit Staff
The bottom of the base is held in place by three screws. To open it, peel back the foam tape donut on the bottom and unscrew the three screws. The base should come apart from the rest of the charger fairly easily once the screws are removed.
Can the position of the primary inductance coild be altered without damaging it once you have the unit open?
I ask in reference to the common problem that these have when the Pre is 100% charged, where it chimes on and off of the "charging" mode. Slightly separating the phone from the Touchstone (with a paper towel or a piece of fabric) solves the problem, but if you could push the coil farther away in the base, that would be a more elegant solution.
Any idea who makes the chipset and materials for the phone portion of the inductive charger?