Center-tapped transformer takes AC from source, steps it down while also creating a paraphrased signal. Full wave rectifier (blue & green) creates positive pulsating DC. Next, the filter (orange) will eliminate the pulsating DC by a charging up to a ripple, and finally our regulator (red), using our zener diode, will steady out the ripple to a nice steady DC. When power switch is turned off, relay is toggled, offering filter a safe path to discharge instead of continuing to light lamp (our load).
Wait a moment after turning on (flipping the switch), for the higher values on the O-scope to move off the left side of the screen, so that it "zooms" in and you can see the pulsating DC, rippling, and steadying more clearly.
