From analytic equations and Fig. 4, several circuit features are observed as follows. A. Steady-state voltage transfer ratio of the asymmetrical half bridge flyback converter is a function of duty cycle and load resistor. And the maximum voltage transfer ratio is proportional to load resistor. B. It is necessary to limit the maximum duty cycle, to sustain stability of converter. Because voltage transfer ratio is a non-monotonic function of duty cycle. C. There is a minimum value of theoretical duty cycle, when converter has no load.