Could any body please help me with the following problem :
Flyback transformer in discontineous mode:
"Vin"=11-12V Dc
"Ipeak"(primary)=520mA, ton(turn-on time)=5us
"Lp"(primary inductance) is calculated by: Lp=(Vin*ton)/Ipeak
A EF20 core is used with "Ae"=31mm^2 and "AL"=1200nH.
Wire with "d"=0.38mm is used.
Air-gap calculated by: "Lg"=[0.4*3.14*Lp*Ipeak^2*10^8]/(Ae*Bmax^2)=0.02mm
"Bmax"=2000Gaus selected.
Primary number of turns by: "Np"=(Bmax*Lg)(0.4*3.14*Ipeak)=8 turns
------
Surprisingly the primary current taken from the power supply during the turn-on time is too small, about 100mA, expected 520mA!!
Questions:Why is the current so small?
Why is the inductance not equal to 100uH,it's about 80uH.
(In each case the current is too small for Lp=80uH or 100uH)
I'll be gratefull if any body can help me with this problem!
thank you very much in advance
Flyback transformer in discontineous mode:
"Vin"=11-12V Dc
"Ipeak"(primary)=520mA, ton(turn-on time)=5us
"Lp"(primary inductance) is calculated by: Lp=(Vin*ton)/Ipeak
A EF20 core is used with "Ae"=31mm^2 and "AL"=1200nH.
Wire with "d"=0.38mm is used.
Air-gap calculated by: "Lg"=[0.4*3.14*Lp*Ipeak^2*10^8]/(Ae*Bmax^2)=0.02mm
"Bmax"=2000Gaus selected.
Primary number of turns by: "Np"=(Bmax*Lg)(0.4*3.14*Ipeak)=8 turns
------
Surprisingly the primary current taken from the power supply during the turn-on time is too small, about 100mA, expected 520mA!!
Questions:Why is the current so small?
Why is the inductance not equal to 100uH,it's about 80uH.
(In each case the current is too small for Lp=80uH or 100uH)
I'll be gratefull if any body can help me with this problem!
thank you very much in advance
