fg5_8 sag and rebound at pulse transformer .tran 100n 20u .step param l list 6m 600u 200u 60u .param l=6m vp 1 0 pwl(0,0)(1U,0)(1.01U,3)(5U,3)(5.01U,0) r1 1 2 10 l1 2 0 {l} r2 2 0 100 .probe .end