In the data sheet for the TL431 (SLVS543M) figures 4 and 6 show the configuration for measuring Ika versus Vka for the on and off conditions.
Is there any way to determine what this curve might look like for the configuration shown in figure 5? My interest is in how much current is drawn by this circuit as Vka approaches the trigger point. I can account for the current through the divider chain, but what about the primary part as it goes from 0V to the trigger point?
Thanks