LED non-isolated drive transformer (two windings) calculation method
T cycle, f frequency
D minimum duty cycle
Vout output voltage
Vin input voltage
Ton magnetizing time
T cycle, f frequency
D minimum duty cycle
Vout output voltage
Vin input voltage
Ton magnetizing time
General non-isolated auxiliary windings according to chip drop VCC operating range.
T = 1 / f
Dmin = Vout / Vin (max)
Ton = T * Dmin
Id = Io * 0.3 (0.3 for the ripple current coefficient)
Inductor voltage V = Vinmin-Vout-0.6 (Schottky voltage drop)
Lmin = V * dt / di
If there are problems please go to the big bit of the forum electronic transformer plate
