Abstract: A circuit board assembly is applied to the field of electronic communications technologies to resolve a prior-art heat dissipation problem of a circuit board. The circuit board assembly combines, on a second circuit board, low-speed signals transmitted between a plurality of I/O modules and an IC chip, and then transmits the combined low-speed signals to the IC chip by using a low-speed cable. A low-speed signal sent by the IC chip to the plurality of I/O modules is extended to a plurality of low-speed signals on the second circuit board, and then the plurality of low-speed signals are separately sent to the plurality of I/O modules. This may be applied to a scenario in which a relatively large quantity of electronic components need to be disposed on a circuit board.

Abstract: An optical phased board includes a plurality of optical waveguide layers and a plurality of isolation layers. Each optical waveguide layer includes a plurality of optical waveguides, and the optical waveguides are arranged side by side. The optical waveguide layers and the isolation layers are arranged in a superimposed manner, and each isolation layer is located between two adjacent optical waveguide layers. The optical phased board includes a two-dimensional optical waveguide array to perform two-dimensional beam scanning.

Abstract: A variable-speed magnetic coupling having a radially movable magnet, comprising a drive disc assembly (I), a driven disc assembly (II), and a speed adjusting device assembly (III). Relative rotation of a speed adjustment sleeve (15) with respect to a drive shaft (16) is achieved by means of contact and fitting of a cylindrical pin (20) with respect to a vertical recess on an inner wall of the drive shaft and to an inclined recess on an inner wall of the speed adjustment sleeve. The speed adjustment sleeve is connected to a circular slotted disc (18) by means of a screw. A permanent magnet (10) is attached to a permanent magnet bearer (9) and inserted into a rectangular through hole of a circular frame (13), and a radial movement of the permanent magnet is enabled by means of a cam and groove sliding block mechanism consisting of the circular slotted disc, the circular frame, the permanent magnet bearer, and the permanent magnet.

Abstract: A disc-type speed regulation magnetic coupler based on bevel gear drive is provided, consisting of a driving disc assembly and a driven disc assembly, wherein a speed regulation device is mounted on the driving disc assembly.

Abstract: A disc-type speed regulation magnetic coupler based on bevel gear drive is provided, consisting of a driving disc assembly and a driven disc assembly, wherein a speed regulation device is mounted on the driving disc assembly.

Abstract: A variable-speed magnetic coupling having a radially movable magnet, comprising a drive disc assembly (I), a driven disc assembly (II), and a speed adjusting device assembly (III). Relative rotation of a speed adjustment sleeve (15) with respect to a drive shaft (16) is achieved by means of contact and fitting of a cylindrical pin (20) with respect to a vertical recess on an inner wall of the drive shaft and to an inclined recess on an inner wall of the speed adjustment sleeve. The speed adjustment sleeve is connected to a circular slotted disc (18) by means of a screw. A permanent magnet (10) is attached to a permanent magnet bearer (9) and inserted into a rectangular through hole of a circular frame (13), and a radial movement of the permanent magnet is enabled by means of a cam and groove sliding block mechanism consisting of the circular slotted disc, the circular frame, the permanent magnet bearer, and the permanent magnet.

Abstract: A gas water heater includes a water tank, a combustion chamber, a burner, a heat exchanger tube at least partially within the water tank, and a fan. The burner receives fuel gas and primary air from a first air-supply channel to create a primary air-fuel mixture for combustion in the combustion chamber with secondary air. The primary air-fuel mixture has a gas concentration above the upper explosive limit of the fuel gas. Secondary air is supplied through a second air-supply channel to the combustion chamber. The secondary air creates a low excess air ratio (e.g., below 1.5) for combustion in the combustion chamber. A totally sealed channel is defined from the air inlet of the fan to the heat exchanger tube.

Abstract: A gas water heater includes a water tank, a combustion chamber, a burner, a heat exchanger tube at least partially within the water tank, and a fan. The burner receives fuel gas and primary air to create a primary air-fuel mixture for combustion in the combustion chamber with secondary air. The primary air-fuel mixture has a gas concentration above the upper explosive limit of the fuel gas. Secondary air is supplied to the combustion chamber through a secondary air conduit that is separate from the burner. The heat exchanger tube receives the products of combustion, transfers heat from the products of combustion to water in the tank, and exhausts of the products of combustion. Only air flows through the fan; no fuel-air mixture flows through the fan. The water heater utilizes partial premix combustion with low excess air ratio and low contaminant emission.