Can you give me information on this 12 volt 10 amp power supply?

Discussion in 'General Electronics Chat' started by eddie500, May 6, 2016.

  1. eddie500

    Thread Starter New Member

    Nov 5, 2011
    This is a cheap 12 volt power supply ordered from china $9 shipped. This is the only small cheap power supply I can find that will take a DC voltage up to 90 volts.

    The two chips with the thermal pad attached to are the following.
    MBR20100CT is a switch mode power rectifier.
    20 A Total (10 A Per Diode Leg) inc._mbrf20100ct-543591.pdf

    RU75N08 is a N-channel advanced power mosfet

    Maybe you can answer some questions about this. You can see a picture with it on my electric bike, it is the one in the sealed aluminum case all the way to the right.

    There are almost no small power supplies on the market that can handle higher 80 DC voltage input and is on the smaller lighter side.

    1) What type of power supply is it?
    2) Any way I can adjust the voltage on it? There are no pots on it.
    3) It is rated for 10 amp peak, 6-7 amps continuous. Any thing I can do to get the output higher?
    4) Anyway to make it lighter in weight by replacing any of the components, especially those heavy steel yellow and green things.
    5) Does it look like a piece of junk?




  2. BR-549

    Well-Known Member

    Sep 22, 2013
    How many amps comes with that 90 volts?

    Or should I say half amps?
  3. tcmtech

    Well-Known Member

    Nov 4, 2013
    A considerable amount more information on your bike project and intentions would be greatly helpful.

    Battery type, capacity and voltage plus motor voltage, current and RPM ratings plus how it drives the bike would be a good start.

    Lastly the bikes weight, your weight and the speed you want on what type of terrain would be good too.

    Best guess now is you are trying to use a 90-volt battery bank to drive a 12-volt motor. Why? o_O

    At the moment in theory you could get ~240 watts of power to the motor which in realistic terms is about 1/3 of a HP or enough to move a 20-pound bike with a 50-pound kid at a rather poor rate of speed on anything but flat smooth surfaces.
    Put an adult on it and it's just enough power to really rub a guy the wrong ways over how useless of a power assist it is. :oops:
  4. eddie500

    Thread Starter New Member

    Nov 5, 2011
    Sorry for not giving more detail. The power supply is just a 12 volt power supply used to power accessories, like lights, and other things. It is not used to power the bike.

    It is powered from the 82 volt battery inside the bike. So I am converting 82 volts to 12 volts with this tiny power supply.

    The bike really has nothing to do with anything, just that the power supply needs to be small and lightweight because it is on an electric bike.
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    Then it's unlikely to last very long :). The input voltage rating is only 72V.
    In answer to your questions:
    1) Switch-mode.
    2) Only if you can reverse-engineer the circuit. But why would you want to? Aren't your lights etc 12V ones?
    3) No.
    4) No.
    5) It looks 'average', but may not have suitable specs for your requirements.