oscilloscope connected to isolation transformer

Discussion in 'The Projects Forum' started by gjo, Oct 30, 2013.

  1. gjo

    Thread Starter New Member

    May 22, 2013
    In the circuit diagram it shows an isolation transformer connected to an lamp dimmer. They placed the ground clip of the oscilloscope to one teinal of the transformer secondary and the probe to measure the diac. Did they place the ground at the terminal to earth reference the entire circuit, or could they have placed it anyehete and gotten same effect?
  2. MaxHeadRoom


    Jul 18, 2013
    Double post?
    The whole idea of the isolation transformer, especially when using 'scope is when using non-isolated equipment, the circuit chassis can be 'live', the 'scope probe common usually being at earth ground potential, will cause an electrical short if the lead is attached to the common and it happens to be a live chassis.
    As mentioned in the other post, you pick a reference point to measure from based on what portion of the circuit you are trying to measure and the result you are trying to obtain?
    Last edited: Oct 30, 2013