* source EXERCISE 6-7
V_V1         VIN 0 PWL
+ TIME_SCALE_FACTOR={1/1}
+ VALUE_SCALE_FACTOR=15
+repeat forever
+(0,0) (0.25,1) (0.75,-1) (1,0)
+endrepeat
R_R1         VIN VO 1k 
D_D1         0 VO D1N4734A 
V_V2         N001070 0  DC 2
D_D2         N001070 VO D1N4001