A single-phase hybrid multilevel inverter capable of producing a higher number of output voltage levels using fewer power switches and DC voltage sources compared to existing multilevel inverters. The levels are synthesized by switching the DC voltage sources in series/parallel combinations. An auxiliary circuit is introduced to double the number of levels by creating an intermediate step in between two levels. In addition, a zero level is introduced to overcome the inherent absence of this level in the original circuit. To improve the total harmonic distortion, a hybrid modulation technique is utilized. A 300 W, a thirteen level multilevel inverter (including the zero level) was designed and constructed. The circuit was tested with a no-load, resistive load and resistive-inductive load. The experimental results closely match simulated and mathematical analyses.

A single-phase hybrid multilevel inverter capable of producing a higher number of output voltage levels using fewer power switches and DC voltage sources compared to existing multilevel inverters. The levels are synthesized by switching the DC voltage sources in series/parallel combinations. An auxiliary circuit is introduced to double the number of levels by creating an intermediate step in between two levels. In addition, a zero level is introduced to overcome the inherent absence of this level in the original circuit. To improve the total harmonic distortion, a hybrid modulation technique is utilized. A 300 W, a thirteen level multilevel inverter (including the zero level) was designed and constructed. The circuit was tested with a no-load, resistive load and resistive-inductive load. The experimental results closely match simulated and mathematical analyses.

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.

Embodiments of the present disclosure disclose a multi-output high-voltage power supply including a channel selection circuit (103) including a plurality of switches; and a high-voltage power supply module (101) connected to the channel selection circuit (103), wherein the high-voltage power supply module (101) includes a fine adjusting power supply component (110) and a plurality of coarse adjusting power supply components (120-1 to 120-N) connected in series, wherein one high-voltage output terminal of the high-voltage power supply module (101) is connected to a common terminal of the channel selection circuit (103), and the other high-voltage output terminal of the high-voltage power supply module (101) is grounded through a current sampling resistor.

Embodiments of the present disclosure disclose a multi-output high-voltage power supply including a channel selection circuit (103) including a plurality of switches; and a high-voltage power supply module (101) connected to the channel selection circuit (103), wherein the high-voltage power supply module (101) includes a fine adjusting power supply component (110) and a plurality of coarse adjusting power supply components (120-1 to 120-N) connected in series, wherein one high-voltage output terminal of the high-voltage power supply module (101) is connected to a common terminal of the channel selection circuit (103), and the other high-voltage output terminal of the high-voltage power supply module (101) is grounded through a current sampling resistor.

In one embodiment, the present invention is directed to an ear tip having a proximal end and a distal end, the eartip including: a transmit coil, the transmit coil including a core of a ferromagnetic material, the ferromagnetic core having a central channel there through, a distal end of the ferromagnetic core positioned at a first opening in a distal end of the ear tip; a passage extending from an opening at a proximal end of the ear tip to the distal end of the ear tip, the passage ending at a second opening in the distal end of the ear tip, wherein a proximal end of the central channel is connected to the passage.

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.

In embodiments of the invention, the present invention is directed to a contact hearing system including: a transmit circuit including a transmit coil positioned in an ear tip, THE transmit circuit having a first bandpass characteristic, wherein the transmit circuit is tuned such that a center of the first bandpass characteristic is set at a first frequency; and a receive circuit including a receive coil positioned on a contact hearing device, the receive circuit having a second bandpass characteristic, wherein the receive circuit is tuned such that a center of the second bandpass characteristic differs from the center of the first bandpass characteristic.

In embodiments of the invention, the present invention is directed to a contact hearing system including: a transmit circuit including a transmit coil positioned in an ear tip, THE transmit circuit having a first bandpass characteristic, wherein the transmit circuit is tuned such that a center of the first bandpass characteristic is set at a first frequency; and a receive circuit including a receive coil positioned on a contact hearing device, the receive circuit having a second bandpass characteristic, wherein the receive circuit is tuned such that a center of the second bandpass characteristic differs from the center of the first bandpass characteristic.