Phase measurment

Discussion in 'General Electronics Chat' started by superway, May 12, 2011.

  1. superway

    Thread Starter Active Member

    Oct 19, 2009

    Enclosed is the hand drawing. The transfomer above is an isolated and step down voltage 100:1 used to measure the phase on Osciloscope. If I applied 3000W between LINE and NEUTRAL on my unit under test of 120vac at terminal, does it affect or burn the transfomer where I used it to measure wavefome on Scope?


  2. Jaguarjoe

    Active Member

    Apr 7, 2010
    Nope. All 3 devices are in parallel so they each will see the same voltage across them. The 100:1 transformer secondary will reflect that voltage on the 'scope.
    Because they are all in parallel, the individual current through each one will be different from the current through the other two components. I'd guess the xfmr draws the least current, probably milliamps, the 3kw whatever it is will draw the most ~25a, and your DUT is in the middle. Read up on parallel circuits.

    How did you get 120v at 25a?
  3. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    It won't, but a word of caution, other than don't play with mains, is that at 3000w, your drawing a pretty heavy current, meaning that your line can supply a heavy current. Your little isolation circuit MUST be fused to protect you and your circuit.