Version 4
SHEET 1 892 692
WIRE 112 144 112 96
WIRE -304 160 -304 128
WIRE -304 272 -304 240
WIRE 112 272 112 224
WIRE -304 384 -304 352
WIRE 112 384 112 336
WIRE -304 496 -304 464
WIRE 112 512 112 464
FLAG 112 272 0
FLAG 112 96 x
FLAG -304 272 0
FLAG -304 128 V1
FLAG -304 496 0
FLAG -304 352 a1
FLAG 112 512 0
FLAG 112 336 y
SYMBOL bv 112 128 R0
WINDOW 123 24 120 Left 2
SYMATTR Value2 IC={x0}
SYMATTR InstName B1
SYMATTR Value V = V(x) + s * (ddt(V(x)) - a * (1 - V(x)) + b * V(x))
SYMBOL voltage -304 144 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 100 0 3 0 10 20)
SYMBOL bv -304 368 R0
SYMATTR InstName B2
SYMATTR Value V=0.001*square(V(V1))
SYMBOL bv 112 368 R0
WINDOW 123 24 120 Left 2
SYMATTR Value2 IC={x0}
SYMATTR InstName B3
SYMATTR Value V = V(x) + s * (ddt(V(x)) - V(a1) * (1 - V(x)) + b * V(x))
TEXT 272 96 Left 2 !.tran 3
TEXT 272 120 Left 2 !.param a=-1, b=3, x0=5
TEXT 272 144 Left 2 !.param s=-1