Touchstone mod..how i think it could be done
well im getting ready to switch from my pre and its hard to give up my 3 touchstone chargers..really hard, this i think seals the transition for me
of course we've seen that video on youtube but how did he do it?
I'm thinking something along the lines of this ~ this is the transition of the induction charging to a pre extended battery/cover:
To make this work with an evo doesnt seem like it'd be that difficult:
1. move the induction charging apparatus to Evo cover
2. add magnets to give strong grip to touchstone (WOOT CAR SOLUTION!)
It seems that the magnet in the Dock is situated to where the + and - "grab" eachother right in the middle of where the stock metal disk is on the TS Back. It's almost like a Horseshoe type of magnetic field in place. So to workaround this I have to put 2 magnets in each corner with the polarities opposite of eachother, but at the same time where the magnetic disks meet has to be centered right in the middle of where the original piece of metals center was at. Kind of hard to explain but here is a pic with the solution. This results in a rediculously strong magnetic hold between the phone and the TS dock, I would say 2 to 3 times as strong as the original TS Back.
(The drawn circles in the pic show where the other magnets are, you cant see them because they are under the plastic)
3. run flat wires from +/- points slightly left to match contact points on back housing
I'm not sure where the contact points on the back housing would connect to but i recall someone else in the forums already researching this and finding suitable points on the board
The question is now would this work and does it all make sense!
From what i recall the touchstone manages the power output which would make it possible to function with other devices
its the middle of the night and im about to pass out..but im just super hyped at the possibly of getting this to work and not having to put my touchstones to waste
- 06-11-2010, 07:44 AM #2
- 06-11-2010, 11:05 AM #3
I sold my TS when i sold my PRE but in the interest of science, I have a friend who's going to donate a TS and inductive back plate to me.
While i definitely like where your head is at, I think you may be over-thinking this. We should share info and bang this thing out real quick. PM me if interested.
- 06-11-2010, 11:11 AM #4
Nice info. I tested the volts last nite and with the Pre's TS back cover on the TS, it has a steady 5.5V. Perfect for charging. BUT measuring the volts the two terminals on the pre, there is no voltage with the battery in. This means that there has to be at least diodes between the battery and the contacts. This makes sense otherwise the battery power would bleed over the coil constantly. So diodes would also be needed.
My worry is if the magnets would screw up the evo compass. Google sky goes crazy if u wave the ts behind the phone. And the evo may not be able to handle the heat or magnets for regular use. What do u think? I would love this mod.
- 06-12-2010, 08:53 PM #5
I think you're going to have to forgo the rare-earth magnets. The field strength of the Eath's field is teeeny tiny compared to the local fields from the magnets and probably saturates the output of the hardware magnetometer. Maybe the less sexy but oh so useful alternative of velcro? Velcro is more universal. Don't believe me, check out the iPad velcro video on youtube, its priceless, well $499 actually!
- 06-13-2010, 05:30 PM #6
- 06-13-2010, 06:29 PM #8
- 06-15-2010, 10:04 AM #9
- 06-15-2010, 11:26 AM #10
Eeeek. I don't like how he did that. I gotta believe u could do it without taking the screws out and soldering to the board. I was thinking is using the thin copper tape (like rc track cars use) instead I'd soldering. This would go right to the battery contacts tho.
- 06-15-2010, 08:26 PM #11
- 09-21-2010, 04:56 PM #12
Has anyone else successfully done this? Its the only thing holding me back from switching to the EVO. I LOVE never having to plug in my phone. It sounds like a small thing but when you have a touchstone mounted in your car and can just magnetically put your phone on it and its charging and streaming bluetooth to your stereo its great. It also looks so much better in your car than all the other big mounts.
- 10-21-2010, 05:33 PM #13
- 10-21-2010, 07:43 PM #14
- 10-21-2010, 09:22 PM #15
- 10-24-2010, 12:21 AM #16
- 10-26-2010, 10:50 AM #17
Im going to try some tape wire that you will insert between the battery contacts and the battery so not to void the warranty. Not sure if it will work or not but worth a shot. Possibly worst case soldering the wire to those contacts instead, that way it could still be removed and you dont have to take the tape off the 6th torx screw that voids the warranty.
I would think since the plates in the battery cover are not magnets, just steel plates, the compass should still be able to be calibrated. Granted they hold residual magnetism, but the battery in the phone acts like one giant magnetic field also yet the compass still works fine...just a thought...
Does that powermat cover just plug into the micro usb port?
- 10-26-2010, 11:51 AM #18
The powermat back is similar to a pre touchstone back, in that it has some type of metal in it which is attracted to the mat. And yes, at the bottom is a small micro usb plug - which is the way it charges the battery. BTW, I have not lost any battery with this solution.
- 08-24-2011, 04:56 PM #19
- 09-21-2012, 06:26 PM #20