Variable Pulse Width and Frequency of Chopper

Variable Pulse Width and Frequency of Chopper

Q. Explain with waveforms the control techniques used for chopper control.

• The average output voltage of the chopper is determined by the ratio T_ON /T.

                    V_Ldc = (T_ON / T) x V volts

• Thus both the pulse width T_ON and the frequency 1/T may be varied so as to get a particular value of (T_ON / T).
• In some choppers T_ON is not explicitly controlled but its value is dependent on the load.
• The user then varies the chopping frequency to obtain the required value of average load voltage.