Abstract: In a power-supply unit for a microwave tube, voltage between a helix power supply terminal and a cathode power supply terminal is divided into voltage slightly lower than the voltage of a collector power supply terminal. Uni-directional conductive means is provided between a voltage dividing point and the collector power supply terminal, and when the voltage of the collector power supply terminal is about to be lower than voltage at the voltage dividing point while the voltage approximates the voltage of the cathode power supply terminal, the uni-directional conductive means conducts and clamps the voltage of the collector power supply terminal so that the voltage is substantially equal to the voltage at the voltage dividing point.

Abstract: In a power-supply unit for a microwave tube, voltage between a helix power supply terminal and a cathode power supply terminal is divided into voltage slightly lower than the voltage of a collector power supply terminal. Uni-directional conductive means is provided between a voltage dividing point and the collector power supply terminal, and when the voltage of the collector power supply terminal is about to be lower than voltage at the voltage dividing point while the voltage approximates the voltage of the cathode power supply terminal, the uni-directional conductive means conducts and clamps the voltage of the collector power supply terminal so that the voltage is substantially equal to the voltage at the voltage dividing point.

Abstract: A power supply control circuit is especially useful for a traveling wave tube, although it may also be used anyplace where desirable. An a-c power voltage is supplied to an input of the control circuit, where its frequency is multiplied to become a voltage having a period which is no greater than the duration of a power voltage fluctuation which might damage the traveling wave tube, unless corrected. The wave form of the multiplied frequency is shaped to provide a comparison voltage wave form, which is compared with a reference voltage. The a-c power voltage applied to said traveling wave tube is controlled responsive to the output of the comparison means.

Abstract: A multi-cavity klystron device having a plurality of resonance cavities, comprising a plurality of movable elements, each of which is mounted on each of said resonance cavities and which is adapted to change the resonance frequency in each cavity, a plurality of tuning means for giving a reciprocal movement to each movable element against a resilient member provided therefor, a plurality of pulse motors coupled to the tuning means, and a preset means for controlling pulse supply to each pulse motor, wherein a predetermined number of pulses stored in the memory units of the preset means are selectively applied to the pulse motors to rotate each pulse motor in correspondence with the number of pulses, thereby changing each resonance frequency of each cavity.

Abstract: The current surge, normally associated with the initial application of a nominal A.C. current to an inductive load, is prevented by preventing the magnetic core of the inductive load from being driven into saturation. Initially, the current is half wave rectified and amplitude limited. The amplitude limitation insures that the core will not be driven into saturation. A voltage detector connected across the inductive load senses only the counter E.M.F. of a polarity opposite to the polarity of the half wave current. When the sensed voltage reaches a predetermined value, a direct connection is provided between the A.C. supply and the inductive load, bypassing the half wave rectifier and the amplitude limiter.