Hello Everybody Please see the attached ciruit. I'm designing 5Kvdc 32uF capacitor charging circuit using typical flyback circuit with 12V battery. There is 555 timer to switch mosfet and then the primary of flyback transformer. At secondary side, there is a series of ten (600 Volts ) diodes, then the capacitor. Both GNDs are same. On examining primary current waveshape, I notice there is not a linear ramp, at first ramp goes up then falls towards zero, it again goes up (higher the previous) then falls towards zero and so on. But during this period transistor is full in saturation, I do not see anything except DC level. Please help me to solve it. Does anybody tell me hap can I improve its efficiency so that it charges faster. Sample.zip