Chapter 1 Power Devices （ Class Hours： 4 ）

　　The manner in which semiconductor devices are used in power equipment is as a switch which is either open or closed. The devices permit current flow in one direction only， being able to withstand a potential difference without current flow in the opposite direction. In applications， the major devices are diodes， thyristors， power transistors， power MOSFETs， insulated gate bipolar transistors and static induction transistors. Other than the diode， all of these devices can withstand a voltage in the forward direction and be turned on or off by a relatively small controlling current or voltage.

　　In this chapter， the characteristics， rather than the physics， of the major power devices will be described. The firing requirements of the devices will be explained. For practical uses the device rating will be specified， and the comparisons of the devices will be introduced.

　　Chapter 2 Rectifying Circuits （ Class Hours： 8+3 ）

　　A rectifier circuit is one which links an a.c. supply to a d.c. load， that is， it converts an alternating voltage supply to a direct voltage. The direct voltage so obtained is not normally level， as from a battery， but contains an alternating ripple component superimposed on the mean （d.c.） level.

　　In this chapter， the various rectifying circuits will be described. They all give a d.c. output， but differ in regard to the a.c. ripple in the output， the mean voltage level， efficiency， and their loading effects on the a.c. supply system. To construct the waveforms of voltages and currents， the functions of the circuits will be explained， and for practical uses， the comparisons of the connections will be introduced.

　　2-1. Circuit nomenclature

　　2-2. Commutating diode

　　2-3. Single-phase half-wave

　　2-4. Single-phase bridge

　　2-4-1 Uncontrolled

　　2-4-2 Fully-controlled

　　2-4-3 Half-controlled

　　2-5. Three-phase half-wave

　　2-6. Three-phase bridge

　　2-7. Six-phase circuits

　　2-8. Summary