SINGLE-PHASE VOLTAGE CONTROLLER
* FILE EE518_17.CIR
* R-L Load
.PARAM PERIOD={1/60}, ALPHA = 30
Vs    1 0 SIN (0 {SQRT(2)*120} 60Hz 0 0 {ALPHA})
vg1   2 4 PULSE (0V 10V         0s 1ns 1ns {PERIOD/2.1} {PERIOD})
vg2   3 1 PULSE (0V 10V {PERIOD/2} 1ns 1ns {PERIOD/2.1} {PERIOD})
R     4 5 2.5ohm
L     5 0 1mH IC=0
Csnub 1 6 0.1uF  ; Snubber across both thyristors
Rsnub 6 4 100ohm
XT1   1 4 2 4 SCR
XT2   4 1 3 1 SCR
.SUBCKT      SCR    1      2        3        2
*            Model  Anode  Cathode  +Control -Control
*            Name                    Voltage  Voltage
S1 1 5 6 2 SMOD
RG 3 4 100ohm
VX 4 2 DC 0V
VY 5 7 DC 0V
DT 7 2 DMOD
RT 2 6 10ohm
CT 6 2 10uF
F1 2 6 POLY(2) VX VY 0 50 11
.MODEL SMOD VSWITCH (RON=0.05 ROFF=1E+6 VON=1.5V VOFF=0V)
.MODEL DMOD D( IS=1E-03 )
.ENDS SCR
.TRAN 5uS 16.6666667ms UIC 
.OPTIONS ABSTOL=1ns RELTOL=1ms VNTOL=1ms ITL5=10000
.FOUR 60Hz V(4) I(R)
.PROBE
.END