bridge rectifier formed by a plurality of diodes d1 d2 d3 and d4 the anode of diode d1 and the cathode of diode d2 are connected to a junction j2 joining capacitor c1 and winding l1 together the anode of diode d3 and the cathode of diode d4 are connected to a junction j3 joining capacitor c2 and winding l2 together one end of a capacitor c3 is connected to a junction j8 joining together the cathodes of diodes d1 and d3 the other end of capacitor c3 and a junction j9 joining together the anodes of diodes d2 and d4 are grounded capacitor c3 serves to filter high frequency components generated by ballast 10 the full bridge rectifier rectifies the ac voltage which is applied to a serial combination of a buffer capacitor cb and diodes d5 and d6 an electrolytic capacitor typically serves as buffer capacitor cb a serial combination of switches s1 and s2 commonly referred to as totem pole arrangement are in parallel with buffer capacitor cb switches s1 and s2 typically are power mosfets with gates g1 and g2 respectively and are turned on and off by a driver not shown connected to gates g1 and g2 a dc blocking capacitor c4 is connected to the junction j4 a junction.