Hi all, i was building a led driver simple buck converter circuit (second picture)using only discrete component. i want to ask if anyone know why my PWM wave output become mirrored? like in the picture. the yellow one is before i connected to the buck circuit. and when i connected to buck circuit it show 2 wave. the new wave is like a shadow to the 1st wave. and in the oscilloscope the frequency and the duty cycle go haywire. please help me. before this it works fine. what broken component in the buck circuit that can possibly caused this? please help me.
thankss
thankss