What are the parts of a full wave rectifier?

Answer 1

There are two basic types of full-wave rectifier. The older type consists of two rectifier diodes,(diodes). The two anodes are strapped together giving the +ve ouyput;the two cathodes are connected to opposite sides of the transformer secondary. This arrangement has the advantage of needing only two diodes, but the disadvantage of needing a centre-tapped secondary on the transformer which provides the -ve output. The newer type is a bridge rectifier. It consists of four diodes in a ring configuration. diode 1 has its anode connected to the +ve out and cathode to side a of transformer. diode 2 has its anode connected to the +ve out and cathode to side b of transformer. diode 3 has anode to side a and cathode to -ve out. diode 4 has anode to side b and cathode to -ve out. This arrangement has the advantage of not needing a centre tap on transformer secondary. The disadvantage of needing four diodes instead of two is moot nowadays because solid-state diodes are very low cost.

Answer 2

It strongly depends on type of the rectifier. The very minimum to get an approximately constant output voltage is a diode and a capacitor. If you need to fulfill requirements concerning input current shape, electromagnetic compatibility, safety and reliability and output, you need diodes, active switches (e.g. MOSFET, IGBT), inductors, capacitors, Transformers, voltage-, current- and temperature sensors, gate-drivers, and a micro controller.