Besides the induction coil and workpiece, the induction generator (source of ac power) is probably the most important component of an overall induction heating system. Such equipment is typically rated in terms of its frequency and maximum output power (in kilowatts). This chapter addresses the selection of power supplies in terms of these two factors as well as the operational features of different types of sources. The six different types of power supplies for induction heating applications covered in this chapter are line-frequency supplies, frequency multipliers, motor-generators, solid-state (static) inverters, spark-gap converters, and radio-frequency power supplies. The chapter discusses the design and characteristics of each of the various types of power supplies.

This chapter focuses on the transfer of energy between the power supply and the induction heating coil. The most efficient transfer requires that the induction heated load and coil be matched to the power supply and that the electrical circuit containing these elements be properly tuned. The chapter describes these procedures, including the processes involved in tuning induction heating circuits and load matching, impedance matching by means of a transformer, and tuning used for specific types of power supplies.

This chapter discusses the basic components in an induction heat treating system. It describes the design and operating characteristics of power supplies, load-matching transformers, tuning capacitors, power regulators, controllers, process monitors, and diagnostic systems. It also provides information on fixtures and work-handling devices, quench systems, and load matching and tuning procedures.

This chapter describes two types of auxiliary equipment required in most induction heating installations: cooling systems and device timers. Water- and vapor-based systems used for cooling the power supply and the induction coil are described. The chapter concludes with a brief discussion of timers, with emphasis on open-loop timing systems.

Coil design for induction heating has been developed and refined over time based on the theoretical principles applied in practice to several simple inductor geometries such as the classical solenoidal coil. This chapter reviews the fundamental considerations in the design of inductors and describes some of the most widely used coils and common design modifications. Specialty coil designs for specific applications are also discussed. The chapter concludes with sections devoted to coil fabrication and design of power-supply leads.

This chapter discusses the maintenance needs of major components in induction heat-treating systems, including power supplies, heat stations, capacitors, high-frequency output stages, induction coils, water systems, quench systems, and fixturing.

Electronics spans a number of devices, their configurations, and properties. A challenge is to identify those electronic subjects essential for failure analysis. This article reviews the normal operation and terminal characteristics of MOSFET. It describes the electronic behavior of bridges, opens, and parametric delay defects, which is essential for understanding the symptoms of a failing IC. These electronic principles are then applied to a CMOS failure analysis technique using a power supply signature analysis.

This chapter provides a brief review of the scientific and technological developments leading to the widespread use of induction heat treating and its many applications in industry.