PURPOSE: To drive a gyrotron with high accuracy and at a low price by producing an output pulse voltage control signal and a pulse wave form rectifying signal from an output voltage detection signal in order to regulate a current control element consisting of transistors.
CONSTITUTION: When driving a gyrotron 17 for heating plasma of a nuclear fusion reactor or the like, output voltage is detected by a detector 15 to be given to a control circuit 20 while producing an output voltage control signal 31 and a pulse wave form rectifying signal 32 according to an output pattern 30. Further, the signal 31 is arranged to control an AC voltage control circuit 23 consisting of thyristors connected in inverse-parallel, so as to determine a voltage level, while the signal 32 is made to control a voltage control element 27 consisting of transistors, so as to rectify pulse form in order to control the primary voltage of a step-up transformer 28. Accordingly, the price can be reduced without using a high voltage quadripole tube as a current control element and also highly accurate control may be carried out.
MAEKAWA AKITSUGU
OGATA FUMIO
FUJINAGA TAKAMASA
HITACHI ENG CO LTD