weird: bridge rectifier boosts voltage WITHOUT capacitor? how?

Discussion in 'The Projects Forum' started by Hamlet, Apr 25, 2016.

  1. Hamlet

    Thread Starter Member

    Jun 10, 2015
    I have a transformer with 16.02v output A.C.
    I put it thru a 35A bridge rectifier, and my voltage reads 20.69 D.C.
    The AC ripple is 10.41

    Am I missing something? I thought my VD.C. = 0.90 X secondary V A.C.
    (14.418v DC)
  2. Papabravo


    Feb 24, 2006
    Where did you get that formula? It's wrong.
    Measuring DC voltage after a bridge rectifier doesn't make a lot of sense so I can't really tell you what to expect. The peak AC voltage out of the transformer into the rectifier is 16.02 * 1.414 = 22.65 volts. Did you forget that AC voltage measurements are RMS (Root Mean Square)? There is no magic here.
    Last edited by a moderator: Apr 26, 2016
    Hamlet likes this.
  3. Hamlet

    Thread Starter Member

    Jun 10, 2015
    Sorry, it was a wiring mistake. I haven't been myself lately, thanks.