A photonic AC-DC voltage and current equivalence converter includes: a photonic chip; a weak thermal link; an isothermal region; a resistive electrode; an isothermal region photonic nanoresonator; an isothermal region waveguide; a chip photonic nanoresonator; and a chip waveguide, such that an ac voltage is determined from matching a temperature rise of the isothermal region due to a primary elevated temperature of the isothermal region when ac voltage is received by the resistive electrode.

An I-V converting module includes: a current output sensor, an I-V transforming circuit, a sampling and holding circuit, a source follower, a loop switch, and a bypass circuit. A drain of the source follower is connected to an input/output end of the sampling and holding circuit. A source of the source follower is connected to an input end of the I-V transforming circuit and an output end of the current output sensor, and a gate of the source follower is connected to an output end of the I-V transforming circuit via the loop switch, and to the bypass circuit. When the loop switch is closed and the bypass circuit is disabled, a feedback loop formed by the source follower, the I-V transforming circuit and the loop switch is conducted, and the I-V converting module enters into a sampling setup stage.

An I-V converting module includes: a current output sensor, an I-V transforming circuit, a sampling and holding circuit, a source follower, a loop switch, and a bypass circuit. A drain of the source follower is connected to an input/output end of the sampling and holding circuit. A source of the source follower is connected to an input end of the I-V transforming circuit and an output end of the current output sensor, and a gate of the source follower is connected to an output end of the I-V transforming circuit via the loop switch, and to the bypass circuit. When the loop switch is closed and the bypass circuit is disabled, a feedback loop formed by the source follower, the I-V transforming circuit and the loop switch is conducted, and the I-V converting module enters into a sampling setup stage.

An ignition device for welding equipment includes a capacitor, a transformer, a high voltage output circuit connected to a secondary winding of the transformer, a discharging switch enabling discharge of the capacitor to a primary winding of the transformer, a charger and an operation control circuit that controls the charger and the discharging switch.

The present invention relates to a power conversion device in the power electronics field. An object of the present invention is to provide a technique of determining whether a switching element operates normally or not from a gate monitor signal of a power conversion device, and predicting a sign of a failure by obtaining the temperature of the switching element from a transient state of the switching voltage of the power conversion circuit as a component of the power conversion device without using a new signal path.

The present invention relates to a power conversion device in the power electronics field. An object of the present invention is to provide a technique of determining whether a switching element operates normally or not from a gate monitor signal of a power conversion device, and predicting a sign of a failure by obtaining the temperature of the switching element from a transient state of the switching voltage of the power conversion circuit as a component of the power conversion device without using a new signal path.

The present invention discloses a cascade type power conversion device and a communication system for the same. Each phase of the cascade type power conversion device comprises a plurality of power modules connected in series and a communication system. The communication system comprises a plurality of low voltage communication units and a plurality of optical fibers. The plurality of low voltage communication units are connected in series and disposed in the plurality of power modules, respectively. And the plurality of optical fibers are connected between the low voltage communication units and a master control system of the cascade type power conversion device.

The present invention discloses a cascade type power conversion device and a communication system for the same. Each phase of the cascade type power conversion device comprises a plurality of power modules connected in series and a communication system. The communication system comprises a plurality of low voltage communication units and a plurality of optical fibers. The plurality of low voltage communication units are connected in series and disposed in the plurality of power modules, respectively. And the plurality of optical fibers are connected between the low voltage communication units and a master control system of the cascade type power conversion device.

The current-to-voltage converter includes an input for the current to be converted, an output for the converted voltage, a current-to-voltage conversion resistor arranged between the output and a reference potential, a processing circuit including a transistor, the input being connected to the output via the transistor, a twin circuit including components identical to and disposed in a similar way to those of the processing circuit, a voltage follower connected at the input to the processing circuit and at the output to the twin circuit, and means for reinjecting the current at the output of the follower into the processing circuit.

A pseudo-resonant element (130) is disposed in series with respect to an inductive load (180) on the inductive load (180) side rather than an output end of an inverter unit (120) constituted of a magnetic energy recovery switch.