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Describe how a semiconductor diode isused as a half wave rectifier. |
Answer» SOLUTION : (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 biasedand no current flows through the load resistance. (IV)This means currentflows through the diode only during positive half cycles and negative half cycles are blocked. Hence in the output we get only positivehalf cycles. (v) Rectifier efficiency is definedas 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 %` |
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