Abstract: A semiconductor structure is provided. The semiconductor structure includes a substrate, a channel layer, a barrier layer, a compound semiconductor layer, a gate electrode, and a stack of dielectric layers. The channel layer is disposed on the substrate. The barrier layer is disposed on the channel layer. The compound semiconductor layer is disposed on the barrier layer. The gate electrode is disposed on the compound semiconductor layer. The stack of dielectric layers is disposed on the gate electrode. The stack of dielectric layers includes layers having different etching rates.

Abstract: A adjustment method for lens driving apparatus is provided, comprising: (a) assembling a lens in a voice coil motor (VCM), with optical axis tilting towards a normal of VCM bottom surface and forming a tilt angle; forming at least three pillars at VCM bottom surface; (b) performing processing on the pillars according to the tilting direction and tilt angle, after processing, at least pillar having a length different from remaining pillars, each pillar having a bottom at first datum plane, and the optical axis perpendicular to first datum plane; (c) an image sensor having an engaging surface engaged to the pillar bottoms and located at the first datum plane, so that the lens optical axis s perpendicular to the engaging surface of the image sensor, resulting in the optical axis of the lens overlapping an axis of the image sensor to achieve 0° tilt angle.

Abstract: A method for operating the DC-to-DC voltage regulator including plural active switches and plural inductors is disclosed. The method including the steps of: turning on the first active switch, and then turning off the first active switch when the current flowing in the first inductor is equal to zero; turning on the third active switch, and then turning off the third active switch when the current flowing in the second inductor is equal to zero; turning on the second active switch, and then turning off the second active switch when the current flowing in the first inductor is equal to zero; and turning on the fourth active switch, and then turning off the fourth active switch when the current flowing in the second inductor is equal to zero.

Abstract: A method for operating the DC-to-DC voltage regulator including plural active switches and plural inductors is disclosed. The method including the steps of: turning on the first active switch, and then turning off the first active switch when the current flowing in the first inductor is equal to zero; turning on the third active switch, and then turning off the third active switch when the current flowing in the second inductor is equal to zero; turning on the second active switch, and then turning off the second active switch when the current flowing in the first inductor is equal to zero; and turning on the fourth active switch, and then turning off the fourth active switch when the current flowing in the second inductor is equal to zero.

Abstract: The disclosure provides a DC-to-AC power inverting apparatus for photovoltaic modules, which comprises two stages: a first stage including a resonant circuit in series, an isolating transformer with three windings, a full-bridge DC-to-AC converting unit operating in a high-frequency switch mode so as to reduce the transformer volume, and a full-wave rectifier; while a second stage including a half-bridge single-phase inverter unit with two active switches. In the first stage, any high-frequency AC signal produced from the primary winding of the isolating transformer is converter into a DC signal by the full-wave rectifier at the secondary winding of the isolation transformer. Moreover, the switching of the two active switches in the second stage is controlled to operate in a low-frequency mode using a switching frequency synchronized with the frequency of the public electrical supply to control the AC output, and thus to reduce the switching loss of the active switches.

Abstract: An apparatus of auto-focus module and the related assembly method are provided. The module includes a focus-driving module and a photo-sensor module. The focus-driving module includes a lens set and a focus-driving device. The outer circumference of the lens is a smooth surface and the inner circumference of the lens holder is also a smooth surface. The assembly method includes the steps of: sheathing the lens into the lens holder of the focus-driving device and fastening the lens to the lens holder to form a focus-driving module; maintaining a gap as the space for adjusting the locations of the focus-driving module and the photo-sensor module, and after adjustment, fastening the focus-driving module and the photo-sensor module.

Abstract: The disclosure provides a DC-to-AC power inverting apparatus for photovoltaic modules, which comprises two stages: a first stage including a resonant circuit in series, an isolating transformer with three windings, a full-bridge DC-to-AC converting unit operating in a high-frequency switch mode so as to reduce the transformer volume, and a full-wave rectifier; while a second stage including a half-bridge single-phase inverter unit with two active switches. In the first stage, any high-frequency AC signal produced from the primary winding of the isolating transformer is converter into a DC signal by the full-wave rectifier at the secondary winding of the isolation transformer. Moreover, the switching of the two active switches in the second stage is controlled to operate in a low-frequency mode using a switching frequency synchronized with the frequency of the public electrical supply to control the AC output, and thus to reduce the switching loss of the active switches.

Abstract: The present disclosure relates to a resonance circuit for DC-link voltage control in a DC-to-AC inverter. The resonance circuit comprises two active switches. Before the active switches of the DC-to-AC inverter are turned on, a DC-link voltage is isolated by the active switches and the active switches of the DC-to-AC inverter are discharged by the resonance circuit to zero voltage at both ends. Then, the active switches of the DC-to-AC inverter are turned on again after the DC-link voltage is charged by the resonance circuit until the DC-link voltage restores to a normal voltage value. Hence, the active switches of the DC-to-AC inverter achieve zero-voltage switching. Not only the switching loss can be reduced to enhance the conversion efficiency, but also the electro-magnetic interference as well as the RF interference due to dynamic transient changes of the voltage (dv/dt) and of the current (di/dt) can be lowered.

Abstract: A power conversion device is provided for converting a DC voltage to an alternating current corresponding to an AC voltage according to the AC voltage, which includes a power conversion unit and an output unit. The power conversion unit converts the DC voltage to a high-frequency current having two envelops corresponding to the waveform of the AC voltage. The output unit includes an inductive circuit, a full-wave rectifying circuit, an inverter circuit and a filter circuit. The inductive circuit provides two induced currents according to the high-frequency current, wherein one induced current and the high-frequency current are in phase, and the other induced current and the high-frequency current are in antiphase. The full-wave rectifying circuit full-wave rectifies the two induced currents. The inverter circuit alternatively transfers the two full-wave rectified induced currents, and thus output an output current. The filter circuit filters the output current to provide the alternating current.

Abstract: The present invention discloses an apparatus for controlling an H-bridge DC-AC inverter, comprising an H-bridge DC-DC converting circuit capable of converting unstable DC power into stable DC power and a full-bridge DC-AC inverting circuit capable of inverting DC power output from the H-bridge DC-DC converting circuit into AC power. The H-bridge DC-DC converting circuit comprises: a first active switching element and a second active switching element; an inductor capable of storing energy; a first passive switching element and a second passive switching element; and a first capacitor and a second capacitor. The full-bridge DC-AC inverting circuit comprises: a third active switching element, a fourth active switching element, a fifth active switching element and a sixth active switching element; an output inductor; and an output capacitor.

Abstract: The present disclosure relates to a resonance circuit for DC-link voltage control in a DC-to-AC inverter. The resonance circuit comprises two active switches. Before the active switches of the DC-to-AC inverter are turned on, a DC-link voltage is isolated by the active switches and the active switches of the DC-to-AC inverter are discharged by the resonance circuit to zero voltage at both ends. Then, the active switches of the DC-to-AC inverter are turned on again after the DC-link voltage is charged by the resonance circuit until the DC-link voltage restores to a normal voltage value. Hence, the active switches of the DC-to-AC inverter achieve zero-voltage switching. Not only the switching loss can be reduced to enhance the conversion efficiency, but also the electro-magnetic interference as well as the RF interference due to dynamic transient changes of the voltage (dv/dt) and of the current (di/dt) can be lowered.

Abstract: The present invention discloses a resonance circuit for use in an H-bridge DC-DC converter, the resonance circuit comprising: an H-bridge converter, capable of converting unstable DC power into stable DC power; a first resonance circuit, disposed on a buck side of the H-bridge converter for reducing the turn-off loss of a first active switching element; and a second resonance circuit, disposed on a boost side of the H-bridge converter for reducing the turn-on loss of a second active switching element. The H-bridge converter comprises: a first active switching element and a second active switching element; a coupled inductor with dual windings capable of storing energy; and a first passive switching element and a second passive switching element.

Abstract: A power conversion device is provided for converting a DC voltage to an alternating current corresponding to an AC voltage according to the AC voltage, which includes a power conversion unit and an output unit. The power conversion unit converts the DC voltage to a high-frequency current having two envelops corresponding to the waveform of the AC voltage. The output unit includes an inductive circuit, a full-wave rectifying circuit, an inverter circuit and a filter circuit. The inductive circuit provides two induced currents according to the high-frequency current, wherein one induced current and the high-frequency current are in phase, and the other induced current and the high-frequency current are in antiphase. The full-wave rectifying circuit full-wave rectifies the two induced currents. The inverter circuit alternatively transfers the two full-wave rectified induced currents, and thus output an output current. The filter circuit filters the output current to provide the alternating current.

Abstract: The present invention discloses an apparatus for controlling an H-bridge DC-AC inverter, comprising an H-bridge DC-DC converting circuit capable of converting unstable DC power into stable DC power and a full-bridge DC-AC inverting circuit capable of inverting DC power output from the H-bridge DC-DC converting circuit into AC power. The H-bridge DC-DC converting circuit comprises: a first active switching element and a second active switching element; an inductor capable of storing energy; a first passive switching element and a second passive switching element; and a first capacitor and a second capacitor. The full-bridge DC-AC inverting circuit comprises: a third active switching element, a fourth active switching element, a fifth active switching element and a sixth active switching element; an output inductor; and an output capacitor.

Abstract: The present invention discloses a resonance circuit for use in an H-bridge DC-DC converter, the resonance circuit comprising: an H-bridge converter, capable of converting unstable DC power into stable DC power; a first resonance circuit, disposed on a buck side of the H-bridge converter for reducing the turn-off loss of a first active switching element; and a second resonance circuit, disposed on a boost side of the H-bridge converter for reducing the turn-on loss of a second active switching element. The H-bridge converter comprises: a first active switching element and a second active switching element; a coupled inductor with dual windings capable of storing energy; and a first passive switching element and a second passive switching element.

Abstract: An inverter circuit and a control circuit thereof for converting DC power from the renewable energy or distributed energy into AC power so as to be fed into the AC utility power system according to related regulations. The inverter circuit comprises a buck-boost inverter, a DC-to-AC inverter comprising two half-bridge inverters, and a by-pass passive switch coupled to an input DC voltage and the positive terminal of a first DC voltage. The inverter circuit of the present invention prevents the switching loss of an active switch and the energy loss of a coupled inductor by use of the by-pass passive switch and improves the efficiency of the inverter circuit by use of voltage feed-forward compensation.

Abstract: An islanding detection method is proposed to overcome the incapability of detecting islanding operations in accordance with prior arts. A distortion for causing a variation of an AC power system is performed, and an AC power system frequency and a voltage variation are detected as the bases for determining the occurrence of an islanding operation.

Abstract: A transformerless power conversion circuit is interconnected with an electric grid and converts an input DC power provided by a power generator into an AC power and feeding the AC power into the grid. The power conversion circuit includes a buck-boost converter converting the input DC power into two sets of DC power levels; and at least one half-bridge inverter converting the two sets of DC power levels into the AC power for feeding into the grid. The isolating transformer can be eliminated and the common ground problem for DC side and AC side is also solved. The power conversion circuit has significant improvement for device size, manufacture cost and conversion efficiency.

Abstract: An inverter circuit and a control circuit thereof for converting DC power from the renewable energy or distributed energy into AC power so as to be fed into the AC utility power system according to related regulations. The inverter circuit comprises a buck-boost inverter, a DC-to-AC inverter comprising two half-bridge inverters, and a by-pass passive switch coupled to an input DC voltage and the positive terminal of a first DC voltage. The inverter circuit of the present invention prevents the switching loss of an active switch and the energy loss of a coupled inductor by use of the by-pass passive switch and improves the efficiency of the inverter circuit by use of voltage feed-forward compensation.

Abstract: An islanding detection and protection method of a parallel-type power converter is proposed, which performs perturbation to a power system to detect the frequency of the system voltage and the variation of the magnitude of the negative-sequence voltage as the basis for deciding the occurrence of an islanding operation. When the system operates normally, the frequency or phase and magnitude of the system voltage and the magnitude of the negative-sequence voltage won't be affected by the perturbation. On the other hand, if an islanding operation occurs, this perturbation will cause an apparent drift of the frequency or phase and magnitude of the system voltage and the magnitude of the negative-sequence voltage. Through detection of this apparent drift, the perturbation can be amplified by means of positive feedback to quickly detect the islanding operation phenomenon and trigger the protection mechanism.