Measurement of Frequency by Wien Robinson's Bridge

  Procedure:

  Fixed Frequency

  1. Set R4 = 2*R3 and Fs = 500Hz.

  2. Switch on the supply voltage to note the unbalanced voltage in the bridge circuit.

  3. Adjust the values of R1, C1 and R2, C2 such that the bridge gets balanced.

  4. After the Bridge is balanced (i.e. Null point has been obtained), click on the Simulate button to find the "effective" frequency in the bridge.

  5. Note the percentage error in applied frequency and effective frequency

  Varying Frequency

  1. Set the Values of the capacitors and resistors to set the bridge Null point at 1000Hz following the above mentioned steps.

  2. Now keeping all the passive components value fixed, vary the input frequency (not input sinusoidal amplitude) about the center point 1000Hz and note the corresponding unbalanced voltage in a tabular form.

Tutorials Point

  • The current unbalanced bridge voltage reading is:  mV.
    Effective frequency in the balanced bridge:
      ( click on the Calculate button. )

       Fc:    Hz    Percentage error:    %
  • The current unbalanced bridge voltage reading is:  mV.
    Now click Calculate to fill the corresponding dial frequency (Fd), unbalanced voltage (Vm), and error calculated as:



    Percentage Error is:  %


    Observation Table
    Serial no. of ObservationFd HzVm (Volts) Error
    1st
    2nd
    3rd
    4th
    5th


CONTROLS
C 1(0.1 nF) 1.11 uF
C 2(0.1 nF) 1.11 uF
R 1(1 Ohm) 11.1 MOhm
R 2(1 Ohm) 11.1 MOhm
R 3(1 Ohm) 11.1 MOhm
R 4(1 Ohm) 11.1 MOhm