Positive ignition power supply for a magnetron

Claim 2

A power supply for a magnetron which provides a microwave output and has an anode, a cathode, and a filament circuit, said magnetron having proper and improper modes of oscillation, said supply comprising: a high-leakage reactance step-up transformer having a primary winding for connection to an a.c. power source, at least one seconary winding, a magnetizable core having at least one window, and a high reluctance magnetizable shunt path bridging said window between said primary and secondary windings; means for applying a continuous time-varying voltage across the anode-cathode circuit of said magnetron, said means including a full-wave voltage-multiplying rectifier circuit interconnected with said secondary winding and the anode-cathode circuit of the magnetron, said rectifier circuit having sufficient capacitive reactance to increase the voltage across said secondary winding so that the core in the vicinity of the secondary winding is driven into saturation; and means for simultaneously energizing the filament circuit of said magnetron and the anode-cathode circuit thereof whereby the application of said time-varying voltage across said anodecathode circuit insures that the magnetron goes into its proper mode of oscillation when the filament has substantially reached its operating temperature, and whereby said time-varying voltage is regulated so as to be substantially independent of voltage fluctuations in said a.c. power source.

Claim 3

A power supply for a magnetron as set forth in claim 1 wherein the means for energizing the filament circuit of said magnetron includes another secondary winding on said transformer connected to the filament circuit.

Claim 4

A power supply for a magnetron as set forth in claim 1 wherein said voltage-multiplying circuit includes a first diode and a first capacitor connected across the entire secondary winding and a second diode and a second capacitor connected across a portion of the secondary winding whereby said capacitors are alternately charged to different d.c. levels during alternate half cycles of said a.c. power source, said full-wave voltage-multiplying circuit being adapted to provide the anode-cathode circuit of said magnetron with a time-varying voltage which is a composite of the charge on each capacitor and a part of the alternating voltage on the secondary winding.

Claim 5

A power supply for a magnetron as set forth in claim 1 wherein said voltage-multiplying circuit includes a first diode and a first capacitor connected across the entire secondary winding and a second diode and a second capacitor connected across a portion of the secondary winding whereby said capacitors are alternately charged to different d.c. levels during alternate half cycles of said a.c. power source, said full-wave voltage-multiplying circuit being adapted to provide the anode-cathode circuit of said magnetron with a regulated time-varying voltage which is a composite of the charge on each capacitor and a part of the alternating voltage on the secondary winding.

Claim 6

A power supply for a magnetron as set forth in claim 4 wherein the means for energizing the filament circuit of said magnetron includes another secondary winding of said transformer.

Claim 7

A power supply for a magnetron which provides a microwave output and has an anode, a cathode, and a filament circuit, said magnetron having proper and improper modes of oscillation, said supply comprising a step-up transformer having a primary winding for connection to an a.c. power source and a first secondary winding, means for applying a continuous time-varying voltage across the anode-cathode circuit of said magnetron, said means including a full-wave voltage-multiplying rectifier circuit interconnected with said seconary winding and the anode-cathode circuit of the magnetron, said rectifier circuit comprising a voltage doubler including a first diode and a first capacitor connected across said secondary winding and a second diode and a second capacitor connected across said secondary winding whereby said capacitors are alTernately charged to substantially the same d.c. level during alternate half cycles of said a.c. power source, said transformer having a second secondary winding series-connected with said voltage doubler in the anode-cathode circuit of said magnetron whereby a continuous time-varying voltage which is a composite of the charge on each capacitor and the alternating voltage on the second secondary winding is applied across the anode-cathode circuit of said magnetron, and means for simultaneously energizing the filament circuit of said magnetron and the anode-cathode circuit thereof whereby the application of said time-varying voltage across said anode-cathode circuit insures that the magnetron will go into its proper mode of oscillation when the filament has substantially reached its operating temperature.

Claim 8

A power supply for a magnetron which provides a microwave output and has an anode, a cathode, and a filament circuit, said magnetron having proper and improper modes of oscillation, said supply comprising a step-up transformer having a primary winding for connection to an a.c. power source and a first secondary winding, means for applying a continuous time-varying voltage across the anode-cathode circuit of said magnetron, said means including a full-wave voltage-multiplying rectifier circuit interconnected with said seconary winding and the anode-cathode circuit of the magnetron, said rectifier circuit comprising a voltage doubler including a first diode and a first capacitor connected across said secondary winding and a second diode and a second capacitor connected across said secondary winding whereby said capacitors are alTernately charged to substantially the same d.c. level during alternate half cycles of said a.c. power source, said transformer having a second secondary winding series-connected with said voltage doubler in the anode-cathode circuit of said magnetron whereby a continuous time-varying voltage which is a composite of the charge on each capacitor and the alternating voltage on the second secondary winding is applied across the anode-cathode circuit of said magnetron, and means for simultaneously energizing the filament circuit of said magnetron and the anode-cathode circuit thereof whereby the application of said time-varying voltage across said anode-cathode circuit insures that the magnetron will go into its proper mode of oscillation when the filament has substantially reached its operating temperature.

Claim 9

A power supply for a magnetron as set forth in claim 6 wherein the means for energizing the filament of said magnetron includes a third secondary winding of said transformer.

Claim 10

A power supply as set forth in claim 6 wherein the transformer is a high-leakage reactance step-up transformer including a magnetizable core having at least one window, and a high reluctance magnetizable shunt path bridging said window between said primary and at least the first secondary winding, and wherein said voltage doubler has sufficient capacitive reactance to increase the voltage across said first secondary winding so that the core in the vicinity thereof is driven into saturation whereby a regulated voltage, substantially independent of voltage fluctuations in said a.c. power source, is supplied by said voltage doubler.

Claim 11

A power supply for a magnetron as set forth in claim 9 in which the second secondary winding is also wound on the side of the high reluctance magnetizable shunt path opposite the primary winding.

Claim 12

A power supply for a magnetron as set forth in claim 9 wherein the means for energizing the filament of said magnetron includes a third secondary winding of said transformer, and wherein all the secondary windings are wound on the side of the high reluctance magnetizable shunt path opposite the primary winding.