DC Chopper using SCR

DC Chopper using SCR

Tags: DC Chopper using SCR, DC Johnes Chopper using SCR, Turning off main SCR using Auxiliary SCR,,
Overall rating

To construct and analysis of DC Chopper circuit.

Apparatus required

  • DC Chopper kit - 1 Nos
  • Patch cards - Required Nos
  • Power card - 1 Nos
  • CRO - 1 Nos

Circuit Diagram


CRO Settings

  • Time (X) Axis : 5ms/div
  • Voltage (Y) Axis: 20V/div
  • Probe : 1:10 CRO Probe is suitable one.

Initial Settings

  • Ensure the 230V Power Supply is in proper with Tester.
  • Ensure the CRO is working properly with probe checking and proper ground line axis.

Mimic Diagram

Experiment Steps

  • The connections are made as per the circuit diagram given above.
  • The R Load must be 60W bulb or 200ohm/2A Rheostat. The Load is 120mH/2A.
  • When the load is Rheostat, then it must be in maximum position.
  • Turn on the SW2 and observe the waveform across between G1&K1 and G2&K2. And ensure it is like triggering pulse given in model graph.
  • Turn ON SW1 and observe the waveform across the R load and RL Load.
  • Measure the X-axis time interval of ON time of Load Voltage and OFF Time of Load Voltage.
  • Adjust the value of Firing angle and note down the load voltage and current
  • Repeat the step 6.
  • Repeat the experiment for different values of VGS and note down Vo.

*If the connections are made wrong the kit may get damaged.



F output


Vo output













Theory Waveform


Output Waveform


Join the World's Largest Technical Community

we respect your privacy.