(i) A half wave rectifier can be constructed with a single diode. The ac input signal is fed to the primary coil of a transformer. The output signal is taken across the load resistance `R_(L)`.
(ii) During positive half cycle, the diode is formed biased and current flows through the diode.
(iii) During negative half cycle, diode biased and no current flows through the load resistance.
(iv)This means current flows through the diode only during positive half cycles and negative half cycles are blocked. Hence in the output we get only positive half cycles.
(v) Rectifier efficiency is defined as the ratio of output do power to the input ac power.
`eta = ( P_(dc))/(P_(ac)) = (0.406R_(L))/(r_(f)+R_(L))`
where `r_(f)=` Forward distance of a diode , `R_(L) = ` Load resistance
The maximum efficiency of half wave rectifier is `40.6 %`
