ac adapter ratio

Discussion in 'General Electronics Chat' started by John Parker, Feb 27, 2014.

  1. John Parker

    Thread Starter New Member

    Feb 24, 2014
    How can I predict the transformer ratio of a regular ac adapter?
    I would like to disassemble and use up just the transformer to battery operated high voltage project. I need high ratio but I know these adapters transform voltage just near to output voltage.
  2. antonv


    Nov 27, 2012
    Assuming its one of the older transformer/rectifier/filter ones, find the ratio between your mains voltage and the adapter's voltage printed on it. This will give you a slightly low ratio but will get you in the ball park.

    The printed voltage is its output voltage at full load which approaches the transformer's rms output voltage. You are comparing this to your mains voltage which is also an rms voltage.