50Hz precision step phase shifter

Discussion in 'The Projects Forum' started by bading, Jan 19, 2012.

  1. bading

    Thread Starter New Member

    Jan 18, 2012
    10
    0
    I need to test relay (Directional earth fault protection - ANSI code 67 N). I have a Vref=230Vrms, 50Hz.
    I have to apply a voltage V0 to the input relay (Zrelay 2kOhm, Pn 32mVA).
    V0 must have the following characteristics:
    1) regulable 0-8 Vrms
    2) with the phase angle regulable to step angle -54°,-66°,-90°,-114°,-126°,-180°,-244°,-256°,-264°
    Who can help me?
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,000
    3,229
    Does the signal need to be a sinewave?
     
  3. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Sounds like a perfect application for a resolver. Excite sin/cos windings with quadrature reference and pull variable phase shift from rotor. Adjustable through 360 degrees.
     
  4. bading

    Thread Starter New Member

    Jan 18, 2012
    10
    0
    Yes, you must be a sine wave.
    I think to a MAXIM038 with synch reference Vref.
    Do you have other ideas?
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,000
    3,229
    That device is obsolete.

    The sync connection is an output, not an input.
     
  6. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    Since the frequency is fixed, you could phase shift the voltage using a multistage low pass filter and then use an amplifier to get the needed amplitude back up. Something along the lines of a phase-shift oscillator but without completing the circle and with switching the output to the different stages should work, and since you will be measuring the output voltage anyway you will be setting the make-up gain manually.
     
Loading...