1. Why is the actual experimental output frequency inconsistent with the value of the design parameter?
2. The output frequency of the experiment is sometimes changed, for example, when only the control part power supply is added to the control board, the output frequency of UC3863 is 250K, when the the main power input is added to the circuit to some voltage such as 80V,the frequency change to 290K automatically, and the frequency is still 290K after removing the main power input.why.
UC3863 used in open loop control of half bridge LLC