| 摘要 |
PURPOSE:To prevent troubles of a traveling-wave tube dependent upon increment of a helix current by detecting that the source power source voltage of the traveling- wave tube is lowered below a normal value and breaking the voltage supplied to the anode electrode. CONSTITUTION:In input voltage detection circuit 11, transistors 12 and 14 are turned on when the source power source voltage is over a set value. At this time, a voltage is applied to respective electrodes of the collector and the helix, and the bias voltage applied to input terminal 2 is supplied to anode voltage supplying part 16 through delay circuit 15 after several seconds. When the source power source voltage is lowered below the set value, transistors 12 and 14 are turned off, and the bias voltage supply to the anode voltage supplying part is broken. As the result, the voltage which has been supplied to the anode electrode is broken, and the helix current is not flowed, thus preventing troubles. |
