CONTROLLED HALF WAVE RECTIFIER (stepalph.cir)
.PARAM ALPHA=50                    ;establish the parameter alpha
.STEP PARAM ALPHA 50 90 10         ;step alpha from 50 to 90 by 10
.PARAM DLAY={ALPHA/360/60}
.PARAM PW={1/60 - DLAY*1.1}        ;time scr switch remains closed
VS 1 0 SIN(0 {120*SQRT(2)} 60)
R 3 4 2
L 4 5 0.02 IC=0
VDC 5 0 100
SWITCH 1 2 10 0 SMOD               ;simplified model of scr
DIODE 2 3 DMOD
VPULSE 10 0 PULSE(-2V 2V {DLAY} 1NS 1NS {PW} {1/60})
.MODEL SMOD VSWITCH(RON=.001)
.MODEL DMOD D
.TRAN .1MS 16.67MS 0 0.01MS UIC
.PROBE
.END