simple test circuit

V1 in1 0 PULSE(0 2V   100ms 1ns 1ns 1s)
V2 in2 0 PULSE(0 2V   600ms 10ms 10ms 1s)

R11 in1 out 5k
R12 in2 out 5k
R1 out 0 80k

.tran 10us 2s
.end