For a chopper, Vs is the source voltage, R is the load resistance

For a chopper, V_s is the source voltage, R is the load resistance and α is the duty cycle. Rms and average values of thyristor currents for this chopper are—

α.	V_s	,√α.	V_s
	R		R

√α	V_s	,√α.	V_s
	R		R

√α	V_s	,α.	V_s
	R		R

α(1 - α).	V_s	, (1 - α).	V_s
	R		R