Design of the Resistively Loaded Static Frequency Doubler [includes discussion]

A method of design is described which makes use of two calculated points on the load characteristic of the static frequency doubler. The calculated points are the no-load secondary voltage and the secondary short-circuit current. These points can be obtained with good accuracy by piecewise linear approximation of the B-H characteristic of the magnetic core. The calculation of any other load point would require the solution of four transcendental equations. The present method makes use of empirically obtained load characteristics. It was found that the resistively loaded frequency doubler has a load characteristic which can be well approximated by a quarter of an ellipse having the no-load voltage and the short-circuit current as its half axes. This method permits the calculation of the peak output power and the relative size of the static frequency doubler at different prescribed regulations, and gives good guidance in the design of static frequency doublers in sizes ranging from 100 watts to 100 kw. A sample design based on the method described is developed for a 250-watt 60- to 120-cycle single-phase static frequency doubler and the calculated and measured values are compared.