T
treez
Guest
Hello,
The attached LTspice simulation (of a two transistor forward SMPS) shows that the magnetising current (shown by putting expression “I(L1)+0.189*I(L2)” into the waveform window) only rises to 188mA peak.
This is lower than calculated.
Why is this?
The primary voltage bus is 390V
Lp = 7mH
t(ON) = 4us
Therefore, the magnetising current peak, as seen in the primary, should be given by (V.dt)/Lp = 223mA.
Why do we only see 188mA peak magnetising current in the simulation.?
The attached LTspice simulation (of a two transistor forward SMPS) shows that the magnetising current (shown by putting expression “I(L1)+0.189*I(L2)” into the waveform window) only rises to 188mA peak.
This is lower than calculated.
Why is this?
The primary voltage bus is 390V
Lp = 7mH
t(ON) = 4us
Therefore, the magnetising current peak, as seen in the primary, should be given by (V.dt)/Lp = 223mA.
Why do we only see 188mA peak magnetising current in the simulation.?