Magnetic amplifier control of radio-frequency generators

RADIO-frequency (r-f) generators are used in various industrial processes such as soldering, hardening, forging, annealing, etc. The r-f portion of the generator is usually an oscillator comprising one or more large vacuum tubes, a tank circuit, and an inductive coupling or “work” coil. To utilize vacuum-tube capabilities most fully, high voltage is supplied to the tube plates through a rectifier incorporated in the generator. Since high-power vacuum tubes are used, the rectifier is a large one. The control of this rectifier is an important function of the generator, since it affects the power delivered to the load during a heating cycle and, hence, the quality of the product.