Half-wave Rectifier

A half-wave rectifier uses a single diode that conducts only when its anode is positive with respect to its cathode, which happens during one half of each input cycle. During the opposite half cycle the diode is reverse biased and blocks current, so the load receives no output for that interval. Consequently, the output consists of one pulse for every complete input cycle, and the number of output pulses per second equals the number of input cycles per second. Therefore the output ripple frequency is the same as the input frequency, namely 50 Hz. The value 100 Hz corresponds to a full-wave rectifier, which produces two pulses per cycle by using both halves. The value 25 Hz wrongly halves the supply frequency. The value 0 Hz would imply pure DC, which a simple rectifier without smoothing cannot deliver. As a consistency check, since only alternate half cycles pass, the period between successive output pulses equals the full input period of 20 ms, giving exactly 50 pulses per second and confirming a 50 Hz output frequency.