摘要:
A high frequency cathode heater supply for a microwave source includes a SMPS inverter (13) and an isolation transformer (12) having a primary winding (122) arranged to be powered by the SMPS inverter, a monitor winding (123) passing through primary core assemblies of the primary winding and a secondary winding (121) arranged for connection to the cathode heater (11). A current monitor (141) is arranged to monitor a current in the primary windings. Signal processing modules (14, 131, 132) are arranged to receive a first input signal from the monitor winding (123) indicative of a voltage Vh across the cathode heater (11) and a second input signal from the current monitor (141) indicative of a current through the cathode heater. The signal processing modules are arranged to output a control signal to the SMPS inverter to control power supplied to the cathode heater dependent on a monitored resistance of,or monitored power supplied to, the cathode heater as determined from the first input signal and the second input signal.
摘要:
Die Erfindung betrifft eine verbesserte Röhre (100), insbesondere eine Elektronenröhre, und ein verbessertes System zur Ansteuerung der Elektroden und/oder der Heizung einer Röhre sowie zur Bestimmung der Lebensdauer einer Röhre. Eine erfindungsgemäße Röhre (100) weist einen evakuierten oder gasgefüllten Bereich (110) auf, in welchem eine oder mehrere Elektroden (140, 190) sowie Mittel (150) zur Messung der Temperatur einer der Elektroden (140, 190) angeordnet sind. Der Vorteil der vorliegenden Erfindung ist darin zu sehen, daß mit verhältnismäßig geringem Aufwand eine präzise Ermittlung der Elektrodentemperatur einer Röhre (100) erfolgen kann. Dadurch kann zum einen die Lebensdauer der Röhre genauer vorhergesagt werden. Andererseits ist es durch Überwachen der Elektrodentemperatur und entsprechendes Ansteuern der Elektroden und/oder der Elektrodenheizung möglich, die Elektrodentemperatur exakt auf einem gewünschten Wert (Sollwert) zu halten.
摘要:
An emitter for a charged particle beam apparatus is provided, said emitter comprising a filament (3) extending between and being attached to first and second supports (2), an emitter tip (4) attached to the filament (3), and a stabilization element (6) attached to a third support (5) and to the filament (3), wherein the first, second and third supports (2, 5) define a triangle so that the stabilization element (6) extends at least partially in a direction perpendicular to the direction in which the filament (3) extends.
摘要:
A directly heated cathode assembly comprises a cathode button 100 having a concave surface, two electrodes 120, 170 positioned on said cathode button such that the application of a voltage between them causes current to flow through the body of the cathode button thereby causing heat to be produced within the body of the cathode button. The current flow is evenly distributed between the electrodes by an arrangement incorporated within the cathode button illustrated as a maze of insulating pieces 220. This maze causes the current to travel in a path substantially greater in length than the distance between the electrodes.
摘要:
Cette cathode comprend un corps (1) en matière non émissive d'électrons ayant une face non émissive (1A) substantiellement lisse et des éléments en matière émissive (3) ayant chacun une face émissive (9), espacés les uns des autres et fixés au corps (1), par exemple dans des évidements (2) avec leur surface émissive (9) en relief d'une valeur déterminée (3S) par rapport à ladite face non émissive (1A), afin qu'une électrode de protection puisse être placée entre les parties saillantes de ces éléments (3).
摘要:
An electron tube device comprising an electron tube having a line cathode, and an electric power source for supplying power pulses to the line cathode, characterized in that the electron tube device comprises determination means for determining, during a power pulse, the value of a physical quantity which depends on the temperature of the line cathode, comparison means for comparing the value with a reference value and for supplying a control signal, and termination means to end the power pulse in dependence on the control signal. Consequently, the temperature of the line cathode is more stable.
摘要:
Disclosed are a method and apparatus for rapidly heating a thermionic vacuum tube cathode, thereby enabling the vacuum tube to be placed in useful operation shortly after the tube is switched on. Rapid heating of the cathode is achieved by passing current through the cathode, thereby directly heating it. Simultaneously, the cathode is also heated by an indirect radiant heater and by electron bombardment by electrons emitted from the heater. When the cathode reaches its operating temperature, the direct heating current and the electron bombardment are stopped and the cathode is maintained at its operating temperature by the indirect heater alone. Cathode warm-up times of less than 1 second may be attained using this invention.