cupoftea
Advanced Member level 5
Supposing you are doing a 2 tran forward, 373vin, 24vout, 5Aout, at 120kHz.
T/2 = 4.15us
Suppose you are using a PQ26/20 transformer with a 22 turn pri for 2.1mH = Lp.
At 373Vin your D = 0.11 so t(on) = 959ns.
Though during startup, or non-soft-restart, the duty cycle at 373vin would be max , ie 0.5.
This would give t(on) = 4.15us and di(magnetizing) maximum = 0.74A.
This gives a Bpk of 0.585 Teslas.
Its a non gapped ferrite core, so the 0.585T would have it deeply saturated, and it would be hoping that the
primary current sense caught it before impending doom.
So do you Kapton gap 2 Tran Forward cores as a routine? (ie 25um Kapton between the core halves?)
T/2 = 4.15us
Suppose you are using a PQ26/20 transformer with a 22 turn pri for 2.1mH = Lp.
At 373Vin your D = 0.11 so t(on) = 959ns.
Though during startup, or non-soft-restart, the duty cycle at 373vin would be max , ie 0.5.
This would give t(on) = 4.15us and di(magnetizing) maximum = 0.74A.
This gives a Bpk of 0.585 Teslas.
Its a non gapped ferrite core, so the 0.585T would have it deeply saturated, and it would be hoping that the
primary current sense caught it before impending doom.
So do you Kapton gap 2 Tran Forward cores as a routine? (ie 25um Kapton between the core halves?)