This chapter has presented you with a basic description of the theory and operation of a basic power
supply and its components. The following summary is provided to enhance your understanding of power
POWER SUPPLIES are electronic circuits designed to convert ac to dc at any desired level. Almost
all power supplies are composed of four sections: transformer, rectifier, filter, and regulator.
The POWER TRANSFORMER is the input transformer for the power supply.
The RECTIFIER is the section of the power supply that contains the secondary windings of the
power transformer and the rectifier circuit. The rectifier uses the ability of a diode to conduct during one
half cycle of ac to convert ac to dc.
HALF-WAVE RECTIFIERS give an output on only one half cycle of the input ac. For this reason,
the pulses of dc are separated by a period of one half cycle of zero potential voltage.
FULL-WAVE RECTIFIERS conduct on both halves of the input ac cycles. As a result, the dc
pulses are not separated from each other. A characteristic of full-wave rectifiers is the use of a