Abstract: An improved method for zero-voltage switching (ZVS) of a voltage-fed half-bridge using a variable dead band is provided. The duration of the dead band is determined dynamically and is precisely long enough to ensure the absence of shoot-through events while also minimizing or eliminating switching losses and reverse conduction losses. The method generally includes: (a) calculating the equivalent capacitance as seen by the current source charging the midpoint of the half-bridge; (b) calculating the ZVS charge requirement based on the link voltage and the equivalent capacitance; (c) calculating the charge delivered by the current source over time during a dead band vector, equating the result to the ZVS charge requirement, and solving for the ZVS time requirement at each commutation point over the switching cycle; and (d) updating the dead bands for each commutation of each half-bridge in the switched-mode power converter.

Abstract: An electronic door lock includes a motor having a stator and a rotor that rotates relative to the stator. The rotor is configured to rotate a spindle operatively coupled to a deadbolt lock at a 1:1 drive ratio therewith.

Abstract: A power converter is provided. The power converter includes two or more hybrid switching circuits electrically connected to a source or storage element. Each switching circuit includes a wide bandgap device that is parallel-connected to a silicon-based device. The converter further includes a controller that is operatively coupled to each device of the first and second switching circuits. The controller is configured to operate each hybrid switching circuit by (i) activating the silicon-based device for an activation period, (ii) activating the wide bandgap device for a predetermined duty cycle less than the activation period, (iii) deactivating the silicon-based device while the wide bandgap device is activated, and (iv) deactivating the wide bandgap device. The hybrid switching circuits are sequentially operated to convert an alternating current of a power supply into a link voltage for a power converter, for example.

Abstract: Multi-phase-shift control of a power converter is provided. The power converter includes a dual-active-bridge (DAB) converter having a transformer, a first H-bridge coupled to the primary winding of the transformer, and a second H-bridge coupled to the secondary winding of the transformer. The DAB converter is operable to generate two-level and three-level voltage waveforms on the primary winding and on the secondary winding to yield a system which ensures zero-voltage switching and unity power factor over a wide range of input and output voltage levels and power throughputs. In a multi-phase shift (MPS) mode of operation, the DAB converter changes from a two-level voltage in at least one of the windings to a three-level voltage in both windings in response to the instantaneous load being below a predetermined level, resulting in more efficient performance of the DAB converter in light load conditions.

Abstract: A converter for electrical connection to a three-phase electrical grid and a single-phase electrical grid is provided. The converter includes three DAB modules, each for converting a respective alternating current of a three-phase electrical grid. When connected to a single-phase electrical grid, the third DAB module is bi-directional such that it is operable to filter the power output of the first and second DAB modules. The converter further includes a filter capacitor in electrical communication with the third DAB module through a relay, wherein the relay is responsive to a controller to couple the third DAB module to the filter capacitor when the single-phase electrical grid is detected and to couple the third DAB module to a grid rectifier when the three-phase electrical grid is detected.

Abstract: An improved method for zero-voltage switching (ZVS) of a voltage-fed half-bridge using a variable dead band is provided. The duration of the dead band is determined dynamically and is precisely long enough to ensure the absence of shoot-through events while also minimizing or eliminating switching losses and reverse conduction losses. The method generally includes: (a) calculating the equivalent capacitance as seen by the current source charging the midpoint of the half-bridge; (b) calculating the ZVS charge requirement based on the link voltage and the equivalent capacitance; (c) calculating the charge delivered by the current source over time during a dead band vector, equating the result to the ZVS charge requirement, and solving for the ZVS time requirement at each commutation point over the switching cycle; and (d) updating the dead bands for each commutation of each half-bridge in the switched-mode power converter.

Abstract: An electronic door lock includes a controller, a first touch sensor, and a lock operator. The first touch sensor detects touch on an exterior an exterior side of a door. The lock operator is selectively operated by the controller to unlock a deadbolt according to the touch detected by the first touch sensor. The electronic door lock is located on an interior side of the door. The first touch sensor may be electrically coupleable to a deadbolt lock for the deadbolt to act as an electrode of the touch sensor. The first touch sensor may detect the touch capacitively.

Abstract: A power converter is provided. The power converter includes two or more hybrid switching circuits electrically connected to a source or storage element. Each switching circuit includes a wide bandgap device that is parallel-connected to a silicon-based device. The converter further includes a controller that is operatively coupled to each device of the first and second switching circuits. The controller is configured to operate each hybrid switching circuit by (i) activating the silicon-based device for an activation period, (ii) activating the wide bandgap device for a predetermined duty cycle less than the activation period, (iii) deactivating the silicon-based device while the wide bandgap device is activated, and (iv) deactivating the wide bandgap device. The hybrid switching circuits are sequentially operated to convert an alternating current of a power supply into a link voltage for a power converter, for example.

Abstract: An electronic door system is disclosed for a door that selectively closes a door opening of a building structure. The electronic door system includes two or more of a gyroscope that senses angular velocity of the door, an accelerometer that senses acceleration of the door, a capacitive sensor that capacitively senses the building structure, or a microphone that senses sound of the door. The electronic door system also includes a controller that assesses a physical position of the door according to the two or more of the gyroscope, the accelerometer, the capacitive sensor, or the microphone.

Abstract: An electronic door lock includes a controller, a first touch sensor, and a lock operator. The first touch sensor detects touch on an exterior an exterior side of a door. The lock operator is selectively operated by the controller to unlock a deadbolt according to the touch detected by the first touch sensor. The electronic door lock is located on an interior side of the door. The first touch sensor may be electrically coupleable to a deadbolt lock for the deadbolt to act as an electrode of the touch sensor. The first touch sensor may detect the touch capacitively.

Abstract: An electronic door lock includes a controller, a first touch sensor, and a lock operator. The first touch sensor detects touch on an exterior an exterior side of a door. The lock operator is selectively operated by the controller to unlock a deadbolt according to the touch detected by the first touch sensor. The electronic door lock is located on an interior side of the door. The first touch sensor may be electrically coupleable to a deadbolt lock for the deadbolt to act as an electrode of the touch sensor. The first touch sensor may detect the touch capacitively.

Abstract: Multi-phase-shift control of a power converter is provided. The power converter includes a dual-active-bridge (DAB) converter having a transformer, a first H-bridge coupled to the primary winding of the transformer, and a second H-bridge coupled to the secondary winding of the transformer. The DAB converter is operable to generate two-level and three-level voltage waveforms on the primary winding and on the secondary winding to yield a system which ensures zero-voltage switching and unity power factor over a wide range of input and output voltage levels and power throughputs. In a multi-phase shift (MPS) mode of operation, the DAB converter changes from a two-level voltage in at least one of the windings to a three-level voltage in both windings in response to the instantaneous load being below a predetermined level, resulting in more efficient performance of the DAB converter in light load conditions.

Abstract: A structural assembly (900) and method of fabricating the same, the method comprising: providing a first member (204) comprising a bond surface (800) and a plurality of protrusions (802) extending from the bond surface (800), a length of each of the protrusions (802) from the bond surface (800) being less than or equal to 2 mm; providing a second member (202) comprising a fibre-reinforced composite material, the fibre-reinforced composite material comprising a plurality of elongate fibres (902) embedded in a polymer matrix (904); while the polymer matrix (904) is in its plastic state, forcing the second member (202) against the bond surface (800) and the protrusions (802) so as to cause the second member (202) to form onto the bond surface (800) and the protrusions (802); and thereafter causing the polymer matrix (904) to harden, thereby fixing the first member (204) to the bond surface of the second member (202).

Abstract: A control circuit for converting an unbalanced grid voltage into a DC voltage is provided. The control circuit includes a controller having a voltage detection module, a first transformation module, a level shift module, and a second transformation module. The voltage detection module provides voltage component values indicating the voltage in each phase of a three-phase AC power supply. The first transformation module converts the voltage component values from a stationary reference frame into reference voltage signals in a rotating reference frame using a Clarke-Park transform. The level shift module compensates the reference voltage signals to simulate a balanced three-phase AC voltage. The second transformation module converts the compensated reference voltage signals from the rotating reference frame to the stationary reference frame using an inverse Clarke-Park transform.

Abstract: A single stage DAB control circuit for converting an unbalanced grid voltage into a DC voltage is provided. The control circuit includes a controller having a voltage detection module, a first transformation module, a level shift module, and a second transformation module. The voltage detection module provides voltage component values that are indicative of the voltage in each phase of a three-phase AC power supply. The first transformation module converts the voltage component values from a stationary reference frame into reference voltage signals in a rotating reference frame using a Clarke-Park transform. The level shift module compensates the reference voltage signals to simulate an ideal or balanced three-phase AC voltage. The second transformation module converts the compensated reference voltage signals from the rotating reference frame to the stationary reference frame using an inverse Clarke-Park transform.