What is the maximum power conversion efficiency of a full-wave rectifier?
Maximum theoretical power conversion efficiency of a full-wave rectifier is 81.2%, while that of a half-wave rectifier is 40.6%. Remainder is lost as heat, mainly due to the internal resistance of the diodes. Full-wave rectifier has twice the efficiency of half-wave rectifier because it utilizes both half-cycles on the input alternating current while half-wave rectifier uses only one half-cycle. Efficiency denoted as η is better called as conversion ratio or rectification ratio.
Half-wave rectifier η = 4/π2
Full-wave rectifier η = 8/π2