Abstract:
A gas turbine engine having a turbine section cooling system is disclosed which is able to cool the turbine section of the gas turbine engine to an optimal operating temperature range, while at the same time not substantially degrading engine performance. The disclosure provides a number of different structures for doing so including the provision of turning foils, turning holes, and turning grooves within a secondary air flow cavity which turns or directs cooling and parasitic leakage air into the turbine section in a direction in substantial alignment with a gas flow path through the turbine section.
Abstract:
Microwave oven including a cavity for placing food therein, a magnetron for generating a microwave, a waveguide having at least two slots for guiding the microwave from the magnetron to an inside of the cavity, and a stirrer fan rotatably mounted on an inside of the cavity for varying an interfered state of the microwaves periodically, thereby heating the food more uniformly.
Abstract:
Hyperbranched polymers are prepared by a process in which a monomer having the form Ax is reacted with another monomer of the form By, where A and B are functional groups that do not react with themselves, but do react with each other. The process allows synthesis of hyperbranched polymers having a single type of terminal functional group from comonomers, each of which has a single type of functional group. The invention allows greater flexibility in the preparation of a larger variety of different hyperbranched polymers and enables hyperbranched polymers to be prepared at a lower cost as compared with conventional processes using monomers having two types of functional groups that react during polymerization.
Abstract:
Hyperbranched polycarbosilanes, polycarbosiloxanes, polycarbosilazenes and copolymers thereof are prepared by reacting a difunctional or polyfunctional monomer having functional groups of one type (A) without any other functional groups capable of reacting significantly during polymerization, and a difunctional or polyfunctional monomer having functional groups of another type (B) without any other functional groups capable of reacting significantly during polymerization, wherein each A-functional group is reacted with a B-functional group, and wherein at least one of the monomers has a functionality of at least three. The process enables hyperbranched polycarbosilanes, polycarbosiloxanes, polycarbosilazenes and copolymers thereof to be prepared at a lower cost than with conventional synthesis processes, and provides greater flexibility in the preparation of a larger variety of different types of hyperbranched polycarbosilanes, polycarbosiloxanes, polycarbosilazenes and copolymers thereof.
Abstract:
The present invention discloses a functional electrical stimulation system comprising a primary power, a boost module, an energy storage section, an output control relay, an automatic discharge circuit, a foot/hand controlled switch, a current detection chip and a current limiting fuse. The boost module comprises n DC chopper circuits connected in series, and outputs a high voltage of 100-200V. According to an enable signal and a current detection signal, the output control relay disables/enables the DC boost module. The automatic discharge circuit discharges capacitance of the energy storage section automatically when the relay turns off the power input. The Foot/hand controlled switch, the current detection chip and the current limiting fuse form a triple accident protection circuit. The functional electrical stimulation system maximizes the intensity of electrical stimulation within the range that the human body can withstand. Meanwhile, it provides multiple security protection mechanisms and enhanced reliability to avoid danger during the use.
Abstract:
A scheduler and scheduling method that may select a data transmission time interval and a data transmitting station are included in a multi-user Multiple Input Multiple Output (MIMO) communication system. An access point may include a receiver to receive channel measurement signals from stations using a plurality of receive antennas; a channel estimation unit to generate channel state matrices with respect to wireless channels formed from the stations to the receive antennas using the channel measurement signals; and a scheduler to select at least one transmitting station from the stations by considering the channel state matrices and a number of the receive antennas. The receiver may receive a data stream from the selected transmitting stations. Stations receive identifiers corresponding to transmitting stations and/or transmitting antennas to identify stations or antennas for transmitting data streams to the access point.
Abstract:
In accordance with the teachings described herein, systems and methods are provided for a switching mode power supply. In one example, the switching mode power supply may include a transformer, a switching circuit and a switching control circuit. The transformer receives a DC input voltage on a primary winding and generates a DC output voltage on a secondary winding. The switching circuit, which may include a MOSFET switch, is coupled to the transformer and is configured to switch the transformer on and off. The switching control circuit generates a switching control signal to control the switching circuit in order to regulate the DC output voltage of the transformer. The switching control circuit is configured to generate the switching control signal as a function of a timing signal having a varying frequency, wherein the varying frequency of the timing signal causes a switching frequency of the switching circuit to vary over a period of time in order to reduce electromagnetic interference caused by the switching circuit.
Abstract:
Embodiments of LED driver circuits and the associated methods are disclosed herein. In one embodiment, the LED driver circuit comprises a switch-mode converter, a controller, a feedback circuit, and a gating circuit. The feedback circuit includes a current balance circuit. The gating circuit is responsive to both a current feedback signal and a voltage feedback signal and is configured to select one of them as the feedback signal.
Abstract:
In accordance with the teachings described herein, systems and methods are provided for a switching mode power supply. In one example, the switching mode power supply may include a transformer, a switching circuit and a switching control circuit. The transformer receives a DC input voltage on a primary winding and generates a DC output voltage on a secondary winding. The switching circuit, which may include a MOSFET switch, is coupled to the transformer and is configured to switch the transformer on and off. The switching control circuit generates a switching control signal to control the switching circuit in order to regulate the DC output voltage of the transformer. The switching control circuit is configured to generate the switching control signal as a function of a timing signal having a varying frequency, wherein the varying frequency of the timing signal causes a switching frequency of the switching circuit to vary over a period of time in order to reduce electromagnetic interference caused by the switching circuit.
Abstract:
A digital camera and a method for manually focusing the digital camera are disclosed. The digital camera includes an image sensing unit, a buffer memory unit, an image processing unit, and an image display unit. The image sensing unit senses a signal and produces a full-view area image and a focus-view area image. The image sensing unit selectively outputs the full-view area image and the focus-view area image to the buffer memory unit. When the image sensing unit outputs the focus-view area image to the buffer memory unit, the buffer memory unit outputs the focus-view area image to the image display unit for manual focusing operation by users.