Electrical power inverter with sinusoidal output

Claim 2

A dc to ac sinewave power inverter including a source of dc potential, a load transformer and electrically operable switching means connected between the primary side of the load transformer and The dc source for periodically inverting the signal produced by said dc source and passing through said primary side the improvement comprising: a. a commutator transformer, and b. a resonant circuit coupled to said commutator transformer, said commutator transformer and resonant circuit being coupled to the primary side of said load transformer for periodically causing said switching means to switch; c. said switching means including a feedback transformer and switching elements, said switching elements being responsive to the operation of said commutator transformer and resonant circuit through said feedback transformer.

Claim 3

The inverter of claim 1 wherein said commutator transformer includes first and second series connected windings, said resonant circuit being coupled in parallel across said series connected commutator transformer first and second windings.

Claim 4

The inverter of claim 2 wherein one terminal of said dc source is connected to the common terminal of said first and second windings the other terminal of said dc source being connected to said switching elements.

Claim 5

The inverter of claim 3 wherein said load transformer comprises first and second primary windings serially connected to said series connected first and second winding and at least one secondary winding said feedback transformer comprising first and second primary windings serially connected respectively to said first and second primary windings of said load transformer and first and second secondary windings, said switching means comprising first and second transistors the conducting states of said first and second transistors being controlled respectively by the current in said first and second feedback transformer secondary windings.

Claim 6

The inverter of claim 4 wherein said first and second transistors each include a control electrode and first and second additional electrodes, said secondary windings of the feedback transformer being connected respectively between the control electrode and the first additional electrode of each of said transistor, said primary windings of the feedback transformer being connected respectively between the second additional electrode of said transistors and the first and second primary windings of said load transformer, said other terminal of said dc source being connected to said first additional terminals of said transistors.

Claim 7

The inverter of claim 5 wherein said load transformer is a step-up transformer.

Claim 8

A dc to ac inverter of the type including a resonant circuit for determining the frequency of the ac waveform comprising: a. dc power supply b. a load transformer having a primary and secondary side and receiving signals from said power supply c. switching means for periodically inverting the signals from said power supply applied to the load transformer d. a commutator transformer comprising series connected first and second windings, e. a resonant circuit connected in parallel with said series connected first and second windings, f. said commutator transformer and resonant circuit being connected between the primary side of the load transformer and the said power supply, said switching means being responsive to the operation of said commutator transformer and resonant circuit for switching the direction of current flow in said load transformer.

Claim 9

A dc to ac inverter of the type including a resonant circuit for determining the frequency of the ac waveform comprising: a. dc power supply b. a load transformer having a primary and secondary side and receiving signals from said power supply c. switching means for periodically inverting the signals from said power supply applied to the load transformer d. a commutator transformer comprising series connected first and second windings, e. a resonant circuit connected in parallel with said series connected first and second windings, f. said commutator transformer and resonant circuit being connected between the primary side of the load transformer and the said power supply, said switching means being responsive to the operation of said commutator transformer and resonant circuit for switching the direction of current flow in said load transformer.

Claim 10

The inverter of claim 7 wherein said switching means comprises feedback transformer and first and second switching transistors comprising a control electrode and first and second additional electrodes.

Claim 11

The inverter of claim 8 wherein said feedback transformer comprises first and second primary windings serially connected to the primary side of said load transformer and first and second secondary windings connected respectively between the control electrode and the first additional electrode of said switching transistors.

Claim 12

The inverter of claim 9 wherein said load transformer is a step up transformer including first and second primary windinGs and a plurality of secondary windings said resonant circuit being serially connected between said first and second load transformer primary windings; one terminal of said power supply being connected to the common terminal of said first and second commutator transformer windings the other terminal of said power supply being connected to the first additional terminals of said switching transistors, said second additional terminals of said transistors being connected respectively to said first and second feedback transformer primary windings.