The average or dc output voltage of the flyback circuit in F

The average (or dc) output voltage of the flyback circuit in Figure 13.1a is V_o = 24 V at a resistive load of R = 1.2 Ohm. The duty-cycle ratio is k = 60% and the switching frequency is f = 1 kHz. The on-state voltage drops of transistors and diodes are V_t = 1.1 and V_d = 0.7 V, respectively. The turns ratio of the transformer is a = N_s/N_p = 0.20. Determine the average input current I_s, the efficiency eta, the average transistor current I_A, the peak transistor current I_p, the rms transistor current I_R, the open-circuit transistor voltage V_oc, and the primary magnetizing inductor L_p. Neglect the losses in the transformer and the ripple current of the load. I_s = 4A, eta = 0.9631, I_p = 13.33, I_R = 5.96 A, V_oc = 248.1V, L_p = 5.61 mH, k_max = 0.6

Solution

Given that

load resistance R= 1.2ohms

duty cycle ratio k= 60%

switching frequency f=1khz

Vt =1.1v

Vd = 0.7v

turns ratio of transistor a= Ns/Np= .20

a) the average input current Is

b) efficiency can be calculated by the output voltage to input voltage