Self-Oscillating Converters. By: Andrew Gonzales EE136. INTRODUCTION. General Operating Principle How the circuits work Transformer Design for Converter. General Operating Principle. Switching action Maintained by positive feedback from a winding on the main transformer. Frequency
Nfb = = 9.9 turns
The secondary voltage should be 12.6 V because we want the output voltage to be 12 V and there is a 0.6 V diode loss.
Ns = = 42 turns
Im = = 43 mA
Ipeak = 4 x Imean = 172 mA
Ip = 1.5 x Ipeak = 258 mA.
Use a temporary gap and and operate with a dummy load at the required power. Adjust the gap for the required period.
We first calculate the required inductance of the transformer using the following formula:
Lp = = 6.4mH
We can then use this value to calculate the AL factor (nH/turn2)
AL = = 59 nH/turn