Asymmetric AC to DC autotransformer for turboelectric propulsion, and associated systems and methods are described herein. In one embodiment, an asymmetric AC to DC autotransformer includes: a first coil, a second coil and a third coil of a delta winding Each coil is energized at its corresponding input phase. A first plurality of correction windings coupled to the first coil, a second plurality of correction windings coupled to the second coil, and a third plurality of correction windings coupled to the third coil. A bridge rectifier having a plurality of rectifiers is coupled to respective individual correction windings. Phases of the individual correction windings are asymmetric such that individual phase voltages are controlled relative to the opposite input phase. Voltages are unbalanced relative to neutral.

Asymmetric AC to DC autotransformer for turboelectric propulsion, and associated systems and methods are described herein. In one embodiment, an asymmetric AC to DC autotransformer includes: a first coil, a second coil and a third coil of a delta winding Each coil is energized at its corresponding input phase. A first plurality of correction windings coupled to the first coil, a second plurality of correction windings coupled to the second coil, and a third plurality of correction windings coupled to the third coil. A bridge rectifier having a plurality of rectifiers is coupled to respective individual correction windings. Phases of the individual correction windings are asymmetric such that individual phase voltages are controlled relative to the opposite input phase. Voltages are unbalanced relative to neutral.

Impedance matching circuit for radio-frequency amplifier. In some embodiments, an impedance matching circuit can include a primary metal trace having a first end configured to be capable of being coupled to a voltage source for the power amplifier, and a second end configured to be capable of being coupled to an output of the power amplifier. The impedance matching circuit can further include a secondary metal trace having first end coupled to the second end of the primary metal trace, and a second end configured to be capable of being coupled to an output node. The impedance matching circuit can further include a capacitance implemented between the first and second ends of the secondary metal trace, and be configured to trap a harmonic associated with an amplified signal at the output of the power amplifier.

The embodiments relate to a directional coupler including, in each case, one connection for a first, a second, a third, and a fourth port. The coupler includes a first coupling network for providing the connection for the first port and a second coupling network for providing the connection for the second port. The first and second coupling networks are both connected to the connections for the third and fourth ports, wherein the second coupling network has a first inductance connected between the third port and an electrical reference potential, a first capacitance connected between the fourth port and the electrical reference potential, a second capacitance connected between the third port and the second port, and a second inductance connected between the fourth port and the second port.

The embodiments relate to a directional coupler including, in each case, one connection for a first, a second, a third, and a fourth port. The coupler includes a first coupling network for providing the connection for the first port and a second coupling network for providing the connection for the second port. The first and second coupling networks are both connected to the connections for the third and fourth ports, wherein the second coupling network has a first inductance connected between the third port and an electrical reference potential, a first capacitance connected between the fourth port and the electrical reference potential, a second capacitance connected between the third port and the second port, and a second inductance connected between the fourth port and the second port.

An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

A transformer (100, 100′) is disclosed, comprising a first conducting element (110) having a first lobed portion (114) arranged to form a first plurality of lobes (116); and a second conducting element (120) having a second lobed portion (124) arranged to form a second plurality of lobes (126); wherein said first lobed portion (114) overlaps said second lobed portion (124) to define a plurality of enclosed areas (130). The transformer is adapted for applications requiring an autotransformer having a weak, negative magnetic coupling coefficient.

An autotransformer for converting three-phase AC power to nine-phase AC power. The autotransformer includes three coils each having serial connected windings and non-serial connected windings. The combination of the serial and non-serial windings are interconnected to form a polygon for a total of six windings per phase, in an arrangement which reduces the power rating of an autotransformer suitable for 18-pulse AC to DC power converters. There are a plurality of direct outputs that are equal in magnitude and are out of phase with respect to the voltages at the input. The input is offset from the nine outputs to create the required phase magnitudes for DC power converters.

An electric fence energizer including an IPC (isolated power coupling) power transmitter and an IPC power receiver adapted to receive power from the IPC power transmitter and supply power to the energizer. A pulse shaping circuit between an energy source and output transformer of the energizer may include a series inductance of between 2 μH to 20 μH and a parallel capacitance of between 3μF to 30 μF. The energizer output transformer may comprise a primary winding consisting of less than 15 turns and a secondary winding of between 5 and 50 times the number of turns of the primary winding. The energizer may produce a pulse having a duration of between 20 μs and 60 μs and a peak amplitude greater than 5 kV into 300 Ω.