A frequency generator for generating a working frequency for a transmission signal of a rail contact of an axle counter includes a series resonant circuit having a transmitter coil unit of the rail contact and a capacitor. The frequency generator has an inverter, the output of which is connected to the capacitor. The inverter is configured to generate an oscillating voltage and to feed the generated oscillating voltage to the transmitter coil unit of the rail contact via the capacitor. A current transformer synchronizes the output voltage of the inverter to the current in the series resonant circuit. A start-up circuit electrically connected to the inverter is configured to trigger the inverter and to be electrically connected to an input power supply. The frequency generator is a robust and effective circuit for generation of magnetic fields where manufacturing effort and expensive components can be reduced.

A frequency generator for generating a working frequency for a transmission signal of a rail contact of an axle counter includes a series resonant circuit having a transmitter coil unit of the rail contact and a capacitor. The frequency generator has an inverter, the output of which is connected to the capacitor. The inverter is configured to generate an oscillating voltage and to feed the generated oscillating voltage to the transmitter coil unit of the rail contact via the capacitor. A current transformer synchronizes the output voltage of the inverter to the current in the series resonant circuit. A start-up circuit electrically connected to the inverter is configured to trigger the inverter and to be electrically connected to an input power supply. The frequency generator is a robust and effective circuit for generation of magnetic fields where manufacturing effort and expensive components can be reduced.

A thermal increase system includes a cavity, a first electrode disposed in the cavity, a second electrode disposed in the cavity, and a self-oscillator circuit that produces a radio frequency signal that is converted into electromagnetic energy that is radiated into the cavity by the first and second electrodes. The self-oscillating circuit includes the first electrode and the second electrode. In an embodiment, the first electrode is a first plate in a capacitor structure and the second electrode is a second plate in the capacitor structure. The cavity and a load contained within the cavity operates as a capacitor dielectric of the capacitor structure. A resonant frequency of the self-oscillator circuit is at least partially determined by a capacitance value of the capacitor structure.

A power converter for converting a DC input voltage into an AC output voltage, the power converter having a structure of Phi-2 type, and includes an input terminal for the DC input voltage, an output terminal for the AC output voltage, a power switch equipped with a control electrode, a first electrode and a second electrode linked to a reference potential, the power switch being configured to receive a drive signal at the control electrode, the converter further comprising a self-oscillating circuit, connected between the output terminal and the control electrode, and configured to supply and maintain a sinusoidal drive signal to the power switch from the output voltage.

Resonant power converters and inverters comprising a self-oscillating feedback loop coupled from a switch output to a control input of a switching network comprising one or more semiconductor switches (S1, S2). The self-oscillating feedback loop sets a switching frequency of the power converter (100) and comprises a first intrinsic switch capacitance (CGD) coupled between a switch output and a control input of the switching network and a first inductor (LG). The first inductor (LG) is coupled in-between a first bias voltage source and the control input of the switching network and has a substantially fixed inductance. The first bias voltage source is configured to generate an adjustable bias voltage (VBias) applied to the first inductor (LG). The output voltage (V0UT) of the power converter (100) is controlled in a flexible and rapid manner by controlling the adjustable bias voltage (VBias).

Resonant power converters and inverters comprising a self-oscillating feedback loop coupled from a switch output to a control input of a switching network comprising one or more semiconductor switches (S1, S2). The self-oscillating feedback loop sets a switching frequency of the power converter (100) and comprises a first intrinsic switch capacitance (CGD) coupled between a switch output and a control input of the switching network and a first inductor (LG). The first inductor (LG) is coupled in-between a first bias voltage source and the control input of the switching network and has a substantially fixed inductance. The first bias voltage source is configured to generate an adjustable bias voltage (VBias) applied to the first inductor (LG). The output voltage (V0UT) of the power converter (100) is controlled in a flexible and rapid manner by controlling the adjustable bias voltage (VBias).

An inverter device is formed of the two systems of inverters stored inside a cylindrical metal casing. Each inverter converts DC power to three-phase AC power. The inverters are formed of power semiconductor elements, DC bus bars through which DC power supplied to the respective power semiconductor elements, capacitors connected to the DC bus bars, and switches connected between the respective DC bus bars and the DC input terminals. High-impedance switches are disposed in the vicinity of the DC input terminals. Hence, electromagnetic noises generated by switching actions of the power semiconductor elements are circulated within the inverters by way of the capacitors and eventually attenuated.

Provided is a high-frequency power supply device capable of causing an appropriate current to flow through a transformer. A self-oscillation high-frequency power supply device is provided with a DC power supply, an LC resonant circuit, a switching circuit, and a transformer. The LC resonant circuit includes an induction coil for plasma generation and a capacitor. The switching circuit includes a semiconductor element, the switching circuit being configured to subject DC power supplied from the DC power supply to switching processing to supply high-frequency power to the LC resonant circuit. The transformer includes a primary coil included in the LC resonant circuit and a secondary coil connected to the semiconductor element to turn on/off a semiconductor element. The transformer has a coaxial structure in which the primary coil and the secondary coil are coaxially provided. The LC resonant circuit includes a resistor connected in parallel to the primary coil.

A device which, through its self-oscillation, generates a stable high voltage DC or AC output from a low voltage DC input. The device automatically maintains a desired voltage on an output capacitor, despite changes in output load or input voltage. The device is capable of dead-short operation, capacitor charging, high voltage step-up, high efficiency, and high power density. The capability to step up low voltage to high voltage in such a manner paves the way for advancement in battery-to-grid inverter technology, portable welding devices, portable medical devices, aircraft and spacecraft propulsion devices among many other areas.

A device which, through its self-oscillation, generates a stable high voltage DC or AC output from a low voltage DC input. The device automatically maintains a desired voltage on an output capacitor, despite changes in output load or input voltage. The device is capable of dead-short operation, capacitor charging, high voltage step-up, high efficiency, and high power density. The capability to step up low voltage to high voltage in such a manner paves the way for advancement in battery-to-grid inverter technology, portable welding devices, portable medical devices, aircraft and spacecraft propulsion devices among many other areas.