Then the main voltage from the T1 is rectified to DC volt with bridge diode D1-D4 , We use a No 1N4007 that withstand voltage as 1000 V at the current 1A and the DCV is filtered through the capacitor C1 = 220 nanofarad 400 v be the big size electrolytic type , by the voltage drop across C1 is about 311 VDC