High-efficiency single-ended inverter circuit

Claim 2

In a single-ended Class C oscillator having a tuned L-C tank circuit, the improvement comprising: power transistor means having a control element; and saturable core feedback transformer means for supplying intermittent feedback signals to the control element of the transistor means in order to effect periodic transistor means conduction.

Claim 3

The oscillator of claim 1 wherein the feedback transformer means comprises a current transformer.

Claim 4

An inverter circuit connected to a unidirectional voltage at an input and being operable to provide an alternating voltage at an output, comprising: energy-storing inductor means connected to the voltage input; power transistor means having a control element; saturable core feedback transformer means having a primary winding in circuit with the inductor means and the transistor means and having a secondary winding for providing intermittent feedback current to the control element of the transistor means in order to effect periodic transistor means conduction; and energy-storing tank capacitor means in circuit with the power transistor means and the output for interchange of energy with the inductor means when the transistor means in non-conductive, discharge of the capacitor means serving to provide periodic reset current to the saturable transformer means.

Claim 5

An inverter circuit connected to a unidirectional voltage at an input and being operable to provide an alternating voltage at an output, comprising: energy-storing inductor means connected to the voltage input; power transistor means having a control element; saturable core feedback transformer means having a primary winding in circuit with the inductor means and the transistor means and having a secondary winding for providing intermittent feedback current to the control element of the transistor means in order to effect periodic transistor means conduction; and energy-storing tank capacitor means in circuit with the power transistor means and the output for interchange of energy with the inductor means when the transistor means in non-conductive, discharge of the capacitor means serving to provide periodic reset current to the saturable transformer means.

Claim 6

The inverter circuit of claim 3 and rectifier means in series with the transistor means.

Claim 7

The inverter circuit of claim 3 and diode means connected to the control element of the transistor means in order to limit the maximum control element voltage to a predetermined level.

Claim 8

An inverter circuit connected to a DC voltage at an input and being operable to provide an AC voltage at an output connected to a load comprising: energy-storing inductor means connected to the voltage input; power transistor means having a base, an emitter and a collector; saturable core feedback transformer means having a primary winding in series with the inductor means and the transistor means and having a secondary winding connected in circuit with the base-emitter junction thereof in order to provide intermittent feedback current thereto in order to effect periodic transistor means conduction; and energy-storing tank capacitor means connected in parallel with the power transistor means and the output for interchange of energy with the inductor means when the transistor means is non-conductive; whereby periodic energy transfer from the inductor means serves to charge the capacitor means and supply energy to the load and periodic energy transfer from the capacitor means to the inductor means serves to provide reset current to the saturable transformer means.

Claim 9

An inverter circuit connected to a DC voltage at an input and being operable to provide an AC voltage at an output connected to a load comprising: energy-storing inductor means connected to the voltage input; power transistor means having a base, an emitter and a collector; saturable core feedback transformer means having a primary winding in series with the inductor means and the transistor means and having a secondary winding connected in circuit with the base-emitter junction thereof in order to provide intermittent feedback current thereto in order to effect periodic transistor means conduction; and energy-storing tank capacitor means connected in parallel with the power transistor means and the output for interchange of energy with the inductor means when the transistor means is non-conductive; whereby periodic energy transfer from the inductor means serves to charge the capacitor means and supply energy to the load and periodic energy transfer from the capacitor means to the inductor means serves to provide reset current to the saturable transformer means.

Claim 10

The inverter circuit of claim 6 and rectifier means in series with the transistor means.

Claim 11

The inverter circuit of claim 6 and diode means connected across the base-emitter junction of the transistor means in order to limit the control element voltage to a predetermined level.

Claim 12

The inverter circuit of claim 6 and a capacitor for coupling the load to the inverter output.

Claim 13

The inverter circuit of claim 6 and clamping means in circuit with the inverter input for limiting the value of the instantaneous positive output voltage.

Claim 14

The inverter circuit of claim 10 wherein the clamping means comprises a transformer winding tightly coupled to the inductor means.

Claim 15

The inverter circuit of claim 10 wherein the clamping means comprises a clamping transformer winding tightly coupled to the inductor means and further comprises an additional winding on the feedback transformer means in circuit with the clamping transformer winding and the inverter circuit input.

Claim 16

An inverter circuit connected to a DC voltage input and being operable to provide a segmented sine wave voltage output, comprising: at least one power transistor means comprising a base, an emitter and a collector; tank circuit means in circuit with the transistor means and the output and comprising an inductor and a capacitor operable to interchange energy when the transistor means is non-conductive; and means for providing drive current to the transistor means to effect periodic conduction thereof, each conduction period being initiated when the emitter-collector voltage of the transistor means is substantially zero in magnitude.

Claim 17

An inverter circuit connected to a DC voltage input and being operable to provide a segmented sine wave voltage output, comprising: at least one power transistor means comprising a base, an emitter and a collector; tank circuit means in circuit with the transistor means and the output and comprising an inductor and a capacitor operable to interchange energy when the transistor means is non-conductive; and means for providing drive current to the transistor means to effect periodic conduction thereof, each conduction period being initiated when the emitter-collector voltage of the transistor means is substantially zero in magnitude.

Claim 18

The inverter circuit of claim 13 wherein the drive current means is operable to effect transistor means conduction once during each full cycle of the voltage output.