There is described a power supply unit having at least one alternating current (AC) input and at least one direct current (DC) output for producing an output voltage. The power supply unit comprises at least one input transformer coupled to the at least one AC input and at least one rectification circuit defining an AC side and a DC side, and coupled to the at least one input transformer on the AC side. The at least one rectification circuit comprises a diode rectifier section on the AC side comprising at least one set of diode rectifiers, and a controlled rectifier section in series with the diode rectifier section and configured for producing a variable load voltage to modulate the output voltage between a base voltage and a maximum value of the output voltage using at least one set of three single-phase controlled rectifiers usable as one to three DC outputs to form a three-phase controlled rectifier.

In one embodiment, the present invention is directed to a contact hearing system comprising: an ear tip including a transmit coil, wherein the transmit coil is connected to an audio processor, including an H Bridge circuit; a first input to the H Bridge circuit comprising an AND circuit wherein a first input to the AND circuit comprises a carrier signal and a second input to the AND circuit comprises an output of a delta sigma modulation circuit, wherein the delta sigma modulation circuit is a component of the audio processor; and a second input to the H Bridge circuit comprising an NAND circuit wherein a first input to the NAND circuit comprises a carrier signal and a second input to the NAND circuit comprises an output of the delta sigma modulation circuit.

In one embodiment, the present invention is directed to a contact hearing system comprising: an ear tip including a transmit coil, wherein the transmit coil is connected to an audio processor, including an H Bridge circuit; a first input to the H Bridge circuit comprising an AND circuit wherein a first input to the AND circuit comprises a carrier signal and a second input to the AND circuit comprises an output of a delta sigma modulation circuit, wherein the delta sigma modulation circuit is a component of the audio processor; and a second input to the H Bridge circuit comprising an NAND circuit wherein a first input to the NAND circuit comprises a carrier signal and a second input to the NAND circuit comprises an output of the delta sigma modulation circuit.

A semiconductor device and the like with low power consumption are provided. In a semiconductor device including an electrostatic actuator group, an OS transistor and a capacitor are provided in each electrostatic actuator, and a power supply voltage supplied from the outside is boosted in each electrostatic actuator. The use of the OS transistor can retain the boosted voltage for a long period even after the supply of the power supply voltage is stopped. The use of the OS transistor can miniaturize the capacitor.

A system comprises a first 3-phase rectifier having a positive DC lead and a negative DC lead and a second 3-phase rectifier having a positive DC lead and a negative DC lead. The system also includes a 4-phase, 3-level inverter connected to the first and second 3-phase rectifiers. A method comprises receiving variable frequency, 3-phase power from a first generator, receiving variable frequency, 3-phase power from a second generator, rectifying the variable frequency, 3-phase power from each of the first and second generators into DC power. And inverting the DC power into 4-phase, constant frequency power for powering a load.

In embodiments of the invention, the present invention is directed to a contact hearing system, the contact hearing system including: an ear tip, the ear tip including a transmit coil wherein the transmit coil is wound around a core including, at least in part, a ferromagnetic material; and a contact hearing device including a receive coil wherein the receive coil is wound around a core including, at least in part, a non-ferromagnetic material.

In embodiments of the invention, the present invention is directed to a contact hearing system, the contact hearing system including: an ear tip, the ear tip including a transmit coil wherein the transmit coil is wound around a core including, at least in part, a ferromagnetic material; and a contact hearing device including a receive coil wherein the receive coil is wound around a core including, at least in part, a non-ferromagnetic material.

Fluctuations of an output voltage at the time of a sudden change in a load current is suppressed while keeping an increase in size of a device. According to one aspect of the present invention, a high-voltage power supply device capable of outputting a high voltage of both positive and negative polarities in a switchable manner, includes: a first voltage generation unit (1A) configured to output a high voltage of a positive polarity; a second voltage generation unit (1B) configured to output a high voltage of a negative polarity; a first discharging diode (2A) connected to a voltage output end of the first voltage generation unit in a direction in which when a high voltage is outputted to the voltage output end of the first voltage generation unit, the high voltage is applied to the first discharging diode in a reverse biased state; a second discharging diode (2B) connected to a voltage output end of the second voltage generation unit in a direction in which when a high voltage is outputted to the voltage output end of the second generation unit, the high voltage is applied to the second discharge diode in a reverse biased state; a first output circuit connected between the voltage output end of the first voltage generation unit and a polarity switching voltage output end which is common to both the positive and negative polarities, the first output circuit being configured by a first switch (3A1) and a protective resistor (5A) connected in series to each other, the first switch being configured by a voltage-controlled semiconductor switch; a second output circuit connected between the voltage output end of the second voltage generation unit and the polarity switching voltage output end, the second output circuit being configured by a second switch (3B1) and a protective resistor (5A) connected in series to each other, the second switch being configured by a voltage-controlled semiconductor switch; an output capacitor (4) connected in parallel to a load (100) to be connected to the polarity switching voltage output end; a controller (7) configured to control operations of the first voltage generation unit and the second voltage generation unit and opening/closing operations of the first switch and the second switch such that both the first voltage generation unit and the second voltage generation unit are turned on once in a state in which both the operations of the first voltage generation unit and the second voltage generation unit are stopped when switching a polarity of a voltage outputted from the polarity switching voltage output end; a first limitation unit (<

In one embodiment, the present invention is directed to a contact hearing system including: an ear tip including a transmit circuit having a first Q value, wherein the ear tip includes a transmit coil wound on a ferrite core; a contact hearing device including a receive circuit having a second Q value, wherein the first Q value is greater than the second Q value; a receive coil positioned on the contact hearing device, wherein the receive coil includes a core of a non-ferromagnetic material.

In one embodiment, the present invention is directed to a contact hearing system including: an ear tip including a transmit circuit having a first Q value, wherein the ear tip includes a transmit coil wound on a ferrite core; a contact hearing device including a receive circuit having a second Q value, wherein the first Q value is greater than the second Q value; a receive coil positioned on the contact hearing device, wherein the receive coil includes a core of a non-ferromagnetic material.