Generalized circuit topology of voltage level multiplier modules (VLMMs) for use with multilevel inverters (MLIs) and power converter circuits comprising at least one VLMM and a MLI are described herein. The VLMM is configured to receive a first output voltage from the MLI having a first number of voltage levels and to generate a second output voltage having a second number of voltage levels. If the first number of voltage levels is M, and the VLMM is N-fold voltage level multiplier, then second number of voltage levels is M×N+1. Switching pattern generators for use with the VLMM and modulation methods for controlling switching elements of the VLMM are also described herein.

A high-voltage power source for applying high voltage to a nozzle of an ESI ion source includes a charge release assistant section (26) including switch circuits (62 and 65) and other elements for forcing electric charges accumulated at output terminals to be discharged in a polarity-switching operation, whereby the positive/negative switching of the polarity of the output voltage can be quickly performed. In the mass spectrometer according to the present invention, for example, when the voltage applied to the nozzle needs to be changed from Vi to V.sub.2 (where V.sub.1 and V.sub.2 are positive, and V.sub.1>V.sub.2), a voltage control section (20) under the command of a main controller (9) operates a positive voltage generation section (21) and negative voltage generation section (23) so as to temporarily provide a negative output voltage. After a predetermined period of time, the voltage control section operates the positive voltage generation section (21) and negative voltage generation section (23) so as to provide voltage V.sub.2. If the voltage was simply changed from V.sub.1 to V.sub.2, the voltage would decrease slowly and require considerable time for the change. The positive/negative switching of the polarity induces the discharging of the electric charges accumulated at the output terminals, and consequently, the voltage-switching operation from V.sub.1 to V.sub.2 is quickly performed.

A rectifier comprising a chain of transistors for RF-DC conversion. In order to compensate for the thresholds of the transistors, each transistor can be connected to a junction earlier or later in the chain. By using both p-type and n-type transistors in the same chain, the different types of transistors can be compensated in different directions allowing more transistors to be compensated. Additional transistors connected to the gates of transistors of the main chain can allow the transistors of the main chain to be forward compensated at one part of the input cycle and backward compensated in another part to minimize both the voltage threshold of the rectifier and the leakage current. The line for compensation of the voltage threshold during forward conduction can comprise a solid line or a transistor, and if a transistor is used it may be diode-connected.

The invention provides a double-power-supply switching control system for a welding machine and method. The welding machine double-power-supply switching control method comprises the steps of: continuously detecting and modifying an input voltage signal by a signal modification unit; under the control of a control unit, judging, by a judgment unit, whether to perform voltage doubling, controlling to execute voltage doubling switching action, and locking an actual input voltage mode of a welding machine by a locking unit; and finally outputting matched output current by a power supply output unit.

An AC-DC power conversion system provides extended voltage gain characteristic by virtue of controlling a duty cycle of operation associated with the desired input-to-output gain. The AC-DC power conversion system includes an AC-stage, first and second inductors, first and second voltage-doubler stages, a totem-pole rectifier stage, and a DC-stage coupled across the totem-pole rectifier stage. Each voltage-doubler stage includes a first terminal, a second terminal, and a third terminal, wherein a first terminal of the AC-stage is coupled by the first inductor to the first terminal of each voltage-doubler stage and by the second inductor to the third terminal of each voltage-doubler stage. The totem-pole rectifier stage includes first and second terminals coupled, respectively, to the second terminal of the first voltage-doubler stage and the second terminal of the second voltage-doubler stage.

An AC-DC power conversion system provides extended voltage gain characteristic by virtue of controlling a duty cycle of operation associated with the desired input-to-output gain. The AC-DC power conversion system includes an AC-stage, first and second inductors, first and second voltage-doubler stages, a totem-pole rectifier stage, and a DC-stage coupled across the totem-pole rectifier stage. Each voltage-doubler stage includes a first terminal, a second terminal, and a third terminal, wherein a first terminal of the AC-stage is coupled by the first inductor to the first terminal of each voltage-doubler stage and by the second inductor to the third terminal of each voltage-doubler stage. The totem-pole rectifier stage includes first and second terminals coupled, respectively, to the second terminal of the first voltage-doubler stage and the second terminal of the second voltage-doubler stage.

Disclosed herein is a AC direct LED driving apparatus. The light emitting diode (LED) driving apparatus includes: a rectifier configured to receive and rectify an alternating current (AC) voltage; an LED configured to emit light based on a rectified voltage received from the rectifier; a capacitor connected to a first terminal of the LED, and configured to drive the LED while alternating between charging and discharging sections according to a preset cycle; a first current driver connected to a second terminal of the LED and configured to control a path of current flowing in the LED and the capacitor based on different input voltage levels; a second current driver configured to control charging and discharging of the capacitor; and a first diode connected onto a current path of the capacitor and the second current driver, and configured to form a discharging path for driving the LED based on a charged voltage of the capacitor.

A polarity-selectable high voltage direct current power supply including a first drive assembly that transforms a first low voltage DC input into a first medium voltage alternating current output; a first HV output assembly that transforms the first LV AC output into a first HV DC output, wherein the first HV output assembly defines a first input stage; a polarity selector coupled between the second output junction of the first drive assembly and the first and second input stages of the first HV output assembly, the polarity selector operable between a first configuration and a second configuration; wherein in the first configuration the first HV DC output has a positive polarity; and wherein in the second configuration the first HV DC output has a negative polarity.

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.