Abstract: Provided are amino acid sequences of engineered transaminase polynucleotide that are useful for asymmetrically synthesizing chiral amine compounds, and its preparation process and reaction process under industrial-relevant conditions. Also provided are polynucleotide sequences encoding engineered transaminase polypeptides, engineered host cells capable of expressing engineered transaminase polypeptides, and methods of producing chiral amine compounds using engineered transaminase polypeptides. Compared to other enzymes, the engineered transaminase polypeptides provided by this invention have better catalytic activity and stability, and are not inhibited by chiral amine products in the synthesis process. The use of the engineered polypeptides of the present invention for the preparation of chiral amine compound results in higher unit activity, and has good industrial application prospects.

Abstract: A refrigerator with a liner body and a beam, where the beam has an end portion, and the liner body has a liner wall. An insertion groove is on the liner wall, and the end portion is configured to be inserted into the insertion groove. A limit convex pin is on the end portion and a limit groove is on the liner wall and matched with a shape of the limit convex pin. The limit convex pin is configured to be inserted into the limit groove to limit rotation of the beam relative to the liner body. By matching the limit convex pin and the limit groove, the rotation of the beam relative to the liner wall is limited by the liner wall when the beam is under uneven forces, thereby reducing the flip probability of the beam of the refrigerator.

Abstract: A refrigerator with a liner body and a beam, where the beam has an end portion, and the liner body has a liner wall. An insertion groove is on the liner wall, and the end portion is configured to be inserted into the insertion groove. A limit convex pin is on the end portion and a limit groove is on the liner wall and matched with a shape of the limit convex pin. The limit convex pin is configured to be inserted into the limit groove to limit rotation of the beam relative to the liner body. By matching the limit convex pin and the limit groove, the rotation of the beam relative to the liner wall is limited by the liner wall when the beam is under uneven forces, thereby reducing the flip probability of the beam of the refrigerator.

Abstract: A switching power converter is provided with a phase-shifting RC network for phase-shifting a divided version of a drain voltage of a power switch transistor into a phase-shifted voltage. A comparator compares the phase-shifted voltage to a DC bias voltage to detect peaks and valleys during resonant oscillations of the drain voltage of the power switch transistor.

Abstract: A switching power converter is provided with a phase-shifting RC network for phase-shifting a divided version of a drain voltage of a power switch transistor into a phase-shifted voltage. A comparator compares the phase-shifted voltage to a DC bias voltage to detect peaks and valleys during resonant oscillations of the drain voltage of the power switch transistor.

Abstract: An LED lamp comprises one or more LEDs and an LED driver receiving an input signal from a dimmer switch indicative of an amount of dimming for the LED lamp. The LED driver controls regulated current through the one or more LEDs based on the input signal such that an output light intensity of the one or more LEDs substantially corresponds to the amount of dimming for the LED lamp. A regulated output provides operating power for the LED driver. A controller regulates the regulated output to power the LED driver. The controller selects a power source for charging the regulated output from two or more power sources, and the regulated output is charged using the power source selected by the controller.

Abstract: An LED lamp comprises one or more LEDs and an LED driver receiving an input signal from a dimmer switch indicative of an amount of dimming for the LED lamp. The LED driver controls regulated current through the one or more LEDs based on the input signal such that an output light intensity of the one or more LEDs substantially corresponds to the amount of dimming for the LED lamp. A regulated output provides operating power for the LED driver. A controller regulates the regulated output to power the LED driver. The controller selects a power source for charging the regulated output from two or more power sources, and the regulated output is charged using the power source selected by the controller.

Abstract: An LED lamp comprises one or more LEDs and an LED driver receiving an input signal from a dimmer switch indicative of an amount of dimming for the LED lamp. The LED driver controls regulated current through the one or more LEDs based on the input signal such that an output light intensity of the one or more LEDs substantially corresponds to the amount of dimming for the LED lamp. A regulated output provides operating power for the LED driver. A controller regulates the regulated output to power the LED driver. The controller selects a power source for charging the regulated output from two or more power sources, and the regulated output is charged using the power source selected by the controller.

Abstract: The present document relates to driver circuits and/or power converters, e.g. for Solid State Lighting (SSL) devices, such as Light Emitting Diodes (LEDs). A controller for a driver circuit which is configured to provide a drive voltage to a load subject to an input voltage is described. The driver circuit comprises a power converter network and a power transistor. The controller comprises a control transistor which is configured to couple or to decouple a low voltage terminal of the power transistor to or from a low voltage potential, to put the power transistor to a conduction-state or an off-state, respectively. Furthermore, the controller comprises a charging transistor, arranged in parallel to the control transistor, and configured to couple or to decouple the low voltage terminal of the power transistor to a supply voltage capacitor, to put the power transistor to the conduction-state or off-state, respectively.

Abstract: An LED lamp comprises one or more LEDs, an inductive element coupled to an input voltage source and the one or more LEDs, and a switch coupled to the inductive element. A first current detector is coupled between the input voltage source and a ground node of the LED lamp, such that a current detected by the first current detector is proportional to a bulk voltage across the input voltage source. A second current detector is coupled between the inductive element and the ground node, such that current detected by the second current detector is proportional to a drain voltage across the switch. A switch controller controls the switch based on a feedback signal indicative of a voltage across the inductive element, which is generated based on a difference between the current detected by the second current detector and the current detected by the first current detector.

Abstract: An integrated LED controller drives and reads a passive dimmer and controls a power circuit for the LED. The integrated LED controller detects changes in the position of the passive dimmer and causes the power circuit to brighten or dim the LED accordingly. These functions are normally performed by multiple discrete components. However, the integrated LED controller is implemented as a single integrated circuit, thus reducing the size and cost of the LED dimming system. The integrated LED controller can also include a unified timing controller that coordinates the timing of multiple functions within the controller in a manner that reduces the noise sensitivity of the controller.

Abstract: An LED lamp comprises one or more LEDs and an LED driver receiving an input signal from a dimmer switch indicative of an amount of dimming for the LED lamp. The LED driver controls regulated current through the one or more LEDs based on the input signal such that an output light intensity of the one or more LEDs substantially corresponds to the amount of dimming for the LED lamp. A regulated output provides operating power for the LED driver. A controller regulates the regulated output to power the LED driver. The controller selects a power source for charging the regulated output from two or more power sources, and the regulated output is charged using the power source selected by the controller.

Abstract: An LED lamp comprises one or more LEDs, an inductive element coupled to an input voltage source and the one or more LEDs, and a switch coupled to the inductive element. A first current detector is coupled between the input voltage source and a ground node of the LED lamp, such that a current detected by the first current detector is proportional to a bulk voltage across the input voltage source. A second current detector is coupled between the inductive element and the ground node, such that current detected by the second current detector is proportional to a drain voltage across the switch. A switch controller controls the switch based on a feedback signal indicative of a voltage across the inductive element, which is generated based on a difference between the current detected by the second current detector and the current detected by the first current detector.

Abstract: A TRIAC dimmer controller for an LED lamp dynamically adjusts the amount of additional current supplied to the TRIAC dimmer based on the TRIAC dimmer operating mode. A TRIAC dimmer current controller continually senses the TRIAC dimmer current loading and determines a TRIAC dimmer operating mode based on the detected current. The TRIAC dimmer controller compares the detected current with a threshold current value called a TRIAC holding current, and adjusts the amount of bleeder current based on the difference between the detected current and the threshold current value. By continually sensing the TRIAC dimmer current loading, the LED controller regulates the amount of bleeder current supplied to the TRIAC dimmer using a single sink current path to satisfy the TRIAC dimmer current demands of multiple TRIAC dimmer operating modes.

Abstract: The present document relates to driver circuits and/or power converters, e.g. for Solid State Lighting (SSL) devices, such as Light Emitting Diodes (LEDs). A controller for a driver circuit which is configured to provide a drive voltage to a load subject to an input voltage is described. The driver circuit comprises a power converter network and a power transistor. The controller comprises a control transistor which is configured to couple or to decouple a low voltage terminal of the power transistor to or from a low voltage potential, to put the power transistor to a conduction-state or an off-state, respectively. Furthermore, the controller comprises a charging transistor, arranged in parallel to the control transistor, and configured to couple or to decouple the low voltage terminal of the power transistor to a supply voltage capacitor, to put the power transistor to the conduction-state or off-state, respectively.

Abstract: A power converter that controls a collector current of a bipolar junction transistor (BJT) by controlling the base current to the BJT after having determined the gain of the BJT. A gain detection block determines a gain of the BJT during a first mode. A current calculation block generates a current setting for the base current based on the gain of the BJT determined by the gain detection block during a second mode distinct from the first mode. In some embodiments, the power converter may be included in a LED lamp system.

Abstract: The embodiments herein describe a power converter including a controller that estimates input current of the power converter. The controller estimates the input current without explicitly sensing the input current. The estimated input current can be used in various applications such as regulating power factor and total harmonic distortion as well as estimating current required to maintain proper operation of a dimmer switch in light emitting diode lamp systems.

Abstract: The embodiments herein describe a power converter including a controller that estimates input current of the power converter. The controller estimates the input current without explicitly sensing the input current. The estimated input current can be used in various applications such as regulating power factor and total harmonic distortion as well as estimating current required to maintain proper operation of a dimmer switch in light emitting diode lamp systems.

Abstract: A TRIAC dimmer controller for an LED lamp dynamically adjusts the amount of additional current supplied to the TRIAC dimmer based on the TRIAC dimmer operating mode. A TRIAC dimmer current controller continually senses the TRIAC dimmer current loading and determines a TRIAC dimmer operating mode based on the detected current. The TRIAC dimmer controller compares the detected current with a threshold current value called a TRIAC holding current, and adjusts the amount of bleeder current based on the difference between the detected current and the threshold current value. By continually sensing the TRIAC dimmer current loading, the LED controller regulates the amount of bleeder current supplied to the TRIAC dimmer using a single sink current path to satisfy the TRIAC dimmer current demands of multiple TRIAC dimmer operating modes.

Abstract: The embodiments disclosed herein describe the dynamic control of a switching power converter between different operation modes of the switching power converter. In one embodiment, the operation modes of the switching power converter include a switching mode and a linear mode. The switching power converter may be included in a LED lamp system according to one embodiment.