Patent ID: 7034462
Filing Date: 2006-04-25
Classification: H01J

Abstract:
1. A power supply circuit for a traveling-wave tube for applying a voltage to an anode electrode of the traveling-wave tube which is applied with different voltages from a power supply apparatus to a helix electrode, a positive heater electrode, a negative heater electrode, and a cathode electrode, said circuit comprising: a first and second resistors connected in series between the helix electrode and the positive heater electrode or the negative heater electrode of said traveling-wave tube; a first control device made of semiconductor and having a first terminal, a second terminal, and a first control terminal, said first terminal connected to the negative heater electrode, said first control terminal connected to a junction of the first resistor and the second resistor, said first control device turning on when a potential on the helix electrode rises to a predetermined threshold determined by the ratio of the first resistor to the second resistor with respect to a potential on the positive heater electrode or the negative heater electrode to conduct from the first terminal to the second terminal; and a second control device made of a semiconductor and having a third terminal, fourth terminal, and a second control terminal, said second control terminal connected to the second terminal of said first control device, said third terminal connected to the anode electrode of said traveling-wave tube, said fourth terminal connected to the positive heater electrode or the negative heater electrode, said second control device turning on when said first control device is off to maintain the anode electrode and the cathode electrode at the same potential, said second control device turning off when said first control device turns on to generate a potential difference between the anode electrode and the cathode electrode to apply a voltage to the anode electrode.