Abstract:
A centrifugal fan includes a spiral housing, a driving mechanism and multiple internally mounted impellers. The driving mechanism and the centrifugal impeller, rotated by the driving mechanism, are installed in the spiral housing. A spiral flow channel is defined between the centrifugal impeller and the spiral housing. When the centrifugal impeller rotates, airflow is sucked axially into the spiral housing through an inlet opening and moves along each blade of the centrifugal impeller into the spiral flow channel. The centrifugal impeller includes a hub and multiple blades. Each blade is secured to the hub at one end and has at least one vertical convex strip or vertical concave strip at an opposite end, wherein the vertical convex strip or vertical concave strip on each of blade disturbs the airflow across thereof and reduces narrow-band noise.
Abstract:
A RF front-end circuit and a low noise amplifier thereof configured for a receiver are provided. The circuit includes a low noise amplifier and a quadrature passive mixer. The low noise amplifier provides two RF output differential signals to the quadrature passive mixer. The RF signals are down-converted to the differential in-phase baseband signals and the differential quadrature-phase baseband signals. The structure of the RF front-end circuit can avoid the signal and noise interfering between in-phase channel and quadrature-phase channel without using a 25% duty cycle local oscillation generator circuit.
Abstract:
A slim fan includes a casing, a fan module and a ring cover. The casing includes an upper casing which has an opening, and a lower casing. The fan module includes a plurality of fans annularly disposed in the opening, and each of the fans has a first side and a second side opposite to each other. The ring cover is connected to the first side of the fans and exposed out of the opening. The height of the fans is equal to that between the upper casing and the lower casing.
Abstract:
A heat-dissipated fastener including a heat-dissipated plate, an elastic frame and a heat sink module is provided. The elastic frame includes a sheet element, multiple connecting ribs and multiple attaching portions. Two elastic arms extend from two corresponding sides of the sheet element, respectively. The attaching portions are located below the sheet element and attached to the heat-dissipated plate. The connecting ribs are connected to the attaching portion and the sheet element, and an accommodating space is formed by the connecting ribs, the sheet element and the heat-dissipated plate to accommodate the heat sink module. When the heat-dissipated plate is attached to the heat source and the elastic arms are bent and fixed to the circuit board of the heat source, the connecting ribs exert force on the heat-dissipated plate vertically, respectively.
Abstract:
A centrifugal fan is described. The centrifugal fan is suitable for a portable electrical apparatus. A tongue shape is formed from a volute sidewall of a casing of the centrifugal fan and non-parallel to a rotational axis of blades. Therefore, when the blades rotate to generate a wake flow to blow on a surface of the volute sidewall at the tongue shape, noise generated by the centrifugal fan can be decreased.
Abstract:
Remote control system of an electric equipment comprises a control plane and an under-control plane. The control plane comprises a micro controller. A channel switch module has a plurality of channels, and the micro controller is electrically connected to the channel switch module to select one channel of the pluralities of channels or perform a channel switch of the pluralities of channels. A first blue tooth module is electrically connected to the micro controller. A first antenna is connected to first blue tooth module to emit a blue tooth wireless communication signal of the selected channel of the micro controller. The under-control plane comprises a plurality of antennas to receive the blue tooth wireless communication signal. A plurality of second blue tooth modules are connected to the pluralities of antennas respectively. A plurality of control modules are electrically connected to the pluralities of second blue tooth modules respectively. One of the pluralities of control modules corresponding to the selected channel of the micro controller may output a signal. A power source is connected to the pluralities of control modules.
Abstract:
A system for generating milling codes includes a plurality of personal computers (10), a database (14), and an application server (12). The application server, connected between the personal computers and the database, includes a circular hole handling module (125), for handling circular holes of an engineering drawing, and receiving relevant parameters of the circular holes; a non-circular hole handling module (126), for determining and handling all non-circular holes of the engineering drawing, and receiving relevant parameters of the non-circular holes; a milling path generating module (128), for generating milling paths according to the parameters of the circular holes and the non-circular holes; and a milling code generating module (129), for generating milling codes according to the milling paths. A related method for generating milling codes is also provided.
Abstract:
An aluminum extruded fin set includes a substrate and a plurality of dissipation fins mounted upright on it. There are gaps between heat dissipation fins. Each dissipation fin is divided into three child dissipation fins by two slanted cutouts. The child dissipation fin between two slanted cutouts is bent toward the gap between heat dissipation fins. When airflow passes by the gaps, the airflow velocity distribution is modified due to the bent child dissipation fins and the noise spectrum distribution is modified as well. Such a Hay-stack noise spectrum distribution is more comfortable for the listener than a conventional one.
Abstract:
A dissipation module has a dissipation fin module and a centrifugal fan. The centrifugal fan outputs airflow towards the dissipation fin module to remove the heat from it. The centrifugal fan includes a centrifugal impeller mounted on a motor. An outer housing houses the motor and the centrifugal impeller. Convex members or concave portions are formed on an inner wall of the housing outlet so as to reduce noise. The dissipation fin module includes a fin set closely attached to a heat source, as well as an airflow channel housing. Convex members or concave portions are also formed on an inner wall of the airflow channel for reducing noise.