DIY simple voltage regulation for a tablet

Discussion in 'The Projects Forum' started by jdubau55, Nov 28, 2011.

  1. jdubau55

    Thread Starter New Member

    Nov 28, 2011
    I just bought a cheap tablet on Black Friday. The charger is like $30. Other have found the connector used to charge and sync. I don't know much about regulating voltage.

    The tablet needs 15V in order to consider itself as charging. Most USB chargers on plugs only deliver 5V. The stock plug is a very small housing so there can't be too much going on in there.

    I want to just make a simple plug-in-the-wall unit that will take the 110V from the wall down to 15V so that I can make a cheap DIY charge plug. I figure it would be minimal parts to do this. I figure just a few simple components to go from 110V AC to 15V DC.

    Can those who are more familiar with a matter like this chime in onto what would need to be purchased for this? I would like to make 1 or 2 so I can also keep one for traveling.

    Edit: If I were to take a cheap (Monoprice for like under $2) USB charge plug and tear it apart could I replace one component so instead of 5V DC it delivered 15V DC??
    Last edited: Nov 28, 2011
  2. wayneh


    Sep 9, 2010
    Don't be so sure - there could be a hardware handshake that will complicate things.
    It shouldn't be too hard, but you need to know EXACTLY what is required. Three big questions are whether voltage needs to be regulated, what the current demand is, and whether anything else gets communicated to initiate a charge. For instance, an iPod needs to see certain voltages on the USB data pins, otherwise it won't charge. My advice is to Google as much as you can about your device and see if others have answered these questions. Careful examination of the stock charger might help.
    Not likely.
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
  4. jdubau55

    Thread Starter New Member

    Nov 28, 2011
    It's the Asus Transformer TF101. Word is that it won't actually charge unless it sees at least 11VDC. Stock charger is 15VDC. Part# GS25U15-P1J looks promising, but by the time you pay shipping might as well just buy the actual charger @ $30. Was hoping for a sub $10 investment.
  5. tom66

    Senior Member

    May 9, 2009
    It might be possible, but it's not worth your time.

    You'd be best off with a 12V/5A adapter, if it will work on 11V. You can get them cheap on eBay for about £5 each.
  6. jdubau55

    Thread Starter New Member

    Nov 28, 2011

    True, it looks like US pricing is about $10. For either 1A or 2A adapters.

    From Monoprice the adapters are around $2, then $3 to ship, then around $2 for a voltage regulator...

    $10 is still much better than the $30 for the stock one from Asus.