Switching power supply

Claim 2

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, an inductance value of the transformer viewed from the primary side being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulse being applied as the control signal to the switching element.

Claim 3

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, and inductance value of the transformer viewed from the primary side being different from a product of a 2 and an inductance value of the transformer viewed from the secondary side, where a indicates a turn ratio; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 4

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, and inductance value of the transformer viewed from the primary side being different from a product of a 2 and an inductance value of the transformer viewed from the secondary side, where a indicates a turn ratio; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 5

A switching power supply for driving a magnetron, comprising: a D.C. power source; a step-up transformer having an iron core, a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to the magnetron the iron core having two legs, the secondary winding being wound around each of two legs, the primary winding being wound around only one of two legs; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 6

A switching power supply for driving a magnetron, comprising: a D.C. power source; a step-up transformer having an iron core, a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to the magnetron the iron core having two legs, the secondary winding being wound around each of two legs, the primary winding being wound around only one of two legs; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 7

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, an inductance value of the transformer viewed from the primary side being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 8

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, an inductance value of the transformer viewed from the primary side being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 9

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, one of the primary and secondary windings being divided with first and second portions, the magnetic coupling between the first portion and the other winding being made close, the magnetic coupling between the second portion and the other winding being made loose; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 10

A switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to a load, one of the primary and secondary windings being divided with first and second portions, the magnetic coupling between the first portion and the other winding being made close, the magnetic coupling between the second portion and the other winding being made loose; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 11

A switching power supply for driving a magnetron comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to the magnetron, an inductance value of the transformer viewed from the primary side being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 12

A switching power supply for driving a magnetron comprising: a D.C. power source; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to the magnetron, an inductance value of the transformer viewed from the primary side being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 13

A switching power supply for driving a magnetron, comprising: a D.C. power source; a step-up transformer having an iron core, a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to the magnetron, the iron core having two legs, the secondary winding being wound around each of two legs, the primary winding being wound around only one of two legs; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 14

A switching power supply for driving a magnetron, comprising: a D.C. power source; a step-up transformer having an iron core, a primary winding and a secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary winding being connected to the magnetron, the iron core having two legs, the secondary winding being wound around each of two legs, the primary winding being wound around only one of two legs; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to the switching element for forming an oscillation circuit in cooperation with the primary winding; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 15

A microwave oven range comprising: rectifier means for obtaining a D.C. voltage by rectifying a commercial A.C. voltage; a magnetron for supplying microwave power to a microwave heating device; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the rectifier means, the secondary winding being connected to the magnetron, an inductance value of the transformer viewed from the primary wide being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulse being applied as the control signal to the switching element.

Claim 16

A microwave oven range comprising: rectifier means for obtaining a D.C. voltage by rectifying a commercial A.C. voltage; a magnetron for supplying microwave power to a microwave heating device; a step-up transformer having a primary winding and a secondary winding, the primary winding being supplied with electric power from the rectifier means, the secondary winding being connected to the magnetron, an inductance value of the transformer viewed from the primary wide being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel to at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulse being applied as the control signal to the switching element.

Claim 17

A high-voltage switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a pair of secondary windings connected in series to each other, one of the secondary windings being loosely coupled to the primary winding and the other secondary winding being tightly coupled to the primary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary windings being connected to a load, an inductance value of the transformer viewed from the primary side when measured in a state that the secondary side of the transformer is open being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side when measured in a state that the primary side of the transformer is open into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 18

A high-voltage switching power supply comprising: a D.C. power source; a step-up transformer having a primary winding and a pair of secondary windings connected in series to each other, one of the secondary windings being loosely coupled to the primary winding and the other secondary winding being tightly coupled to the primary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary windings being connected to a load, an inductance value of the transformer viewed from the primary side when measured in a state that the secondary side of the transformer is open being different from a converted secondary inductance value of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side when measured in a state that the primary side of the transformer is open into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and secondary windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 19

A high-voltage switching power supply comprising: a D.C. power source; a step-up transformer having a pair of primary windings connected in series to each other and a secondary winding, one of the primary windings being loosely coupled to the secondary winding and the other primary winding being tightly coupled to the secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary windings being connected to a load, an inductance value of the transformer viewed from the primary side when measured in a state that the secondary side of the transformer is open being different from a converted secondary inductance of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side when measured in a state that the primary side of the transformer is open, into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and second windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.

Claim 20

A high-voltage switching power supply comprising: a D.C. power source; a step-up transformer having a pair of primary windings connected in series to each other and a secondary winding, one of the primary windings being loosely coupled to the secondary winding and the other primary winding being tightly coupled to the secondary winding, the primary winding being supplied with electric power from the D.C. power source, the secondary windings being connected to a load, an inductance value of the transformer viewed from the primary side when measured in a state that the secondary side of the transformer is open being different from a converted secondary inductance of the transformer, the converted secondary inductance value being obtained by converting an inductance value of the transformer viewed from the secondary side when measured in a state that the primary side of the transformer is open, into an inductance value on the primary side; a switching element connected in series with the primary winding for repeating an ON-OFF operation in accordance with a control signal; a capacitor connected in parallel with at least one of the switching element, the primary winding and the secondary winding, for forming an oscillation circuit in cooperation with one of the primary and second windings; and a control device for periodically generating an ON-pulse which makes the switching element conductive for a predetermined period, to supply a series of ON-pulses to the switching element, the ON-pulses being applied as the control signal to the switching element.