Stabilized 400 to 3600 c/s magnetic frequency multiplier

This paper presents detailed design information and performance characteristics of a stabilized 400 to 3600 c/s frequency transformer of the phase multiplier type. The described three-phase-operated prototype design provides a maximum output power of 40 watts. The performance is such that, with output power values up to about 20 watts, actual variations of the 3600 c/s output voltage are ±0.1 to 0.3 percent, although the 400 c/s supply voltage may be changed within the wide range of 80 to 220 volts. As a result of the application of square-loop core material (Orthonol 2-mil tape cores), the waveform of the square-wave output voltage is similar to that of a switching transistor magnetic core multivibrator. Since the output terminals can be permanently short-circuited, the frequency multiplier protects itself and the equipment it supplies from overloads. In view of these properties, the described prototype design will be valuable for those applications in control engineering, where simplicity, ruggedness, extreme reliability, and almost unlimited life, are of prime importance.