Abstract: The variable gain amplifier of the present invention includes at least an operation amplifier. By choosing one of output stages, a feedback resistor is selected and the gain of the variable gain amplifier is decided according to the resistance of the selected feedback resistor, as desired. By adjusting the gain of the variable gain amplifier, the received signals can be amplified or attenuated in accordance with design requirement. The variable gain amplifier can include a two-stage architecture, in which a first stage is used for coarse gain adjustment and a second stage is used for fine gain adjustment. The gain of the two-stage variable gain amplifier can be easily adjusted to a desired value.

Abstract: A glasses structure has a lens frame and a temple. The lens frame has a curved portion disposed at a side thereof and a shaft portion downwardly extending from the curved portion. The temple has a positioning portion disposed at an end thereof, a position opening defined inside the positioning portion, a bushing portion downwardly extending from the positioning portion and a hole defined inside the bushing portion. The shaft portion of the lens frame is inserted into the hole of the temple and the curved portion of the lens frame is held in the position opening of the temple so that the temple pivots on the lens frame.

Abstract: A transmission device for a 2D image display module includes rods in the box, a transmission element slidably mounted around the rods, a motor in the box and having a disk rotatably connected to a motor shaft, a driving rod eccentrically formed on top of the disk and a driving board provided with a slot defined to receive therein the driving rod, wherein distal ends of the transmission element are securely connected to the driving board, and a securing member securely connected to the transmission element to be adapted to connect to either the backboard or the lens. Rotation of the driving rod is able to drive the driving board to move, which drives the lens to move opposite to the driving board so that the image is revealed as a result of relative movement between the backboard and the lens.

Abstract: An anchoring screw with triple threads of different depths of thread especially useful for coupling with a construction hole on a cement wall (or other construction boards and panels) includes a first bolt section, a tool driven section and a second bolt section. The second bolt section has a first screw thread, a second screw thread and a third screw thread of different depths of thread formed on the outer surface that are spaced from one another at 120 degrees. Thus, the screw threads can gather extruded cement debris when the screw is fastened into the construction hole to produce a stronger fastening effect. As there is no expansion incurred, the wall or board does not crack. Therefore, the interval between the construction holes may be shortened, and the number of construction holes may be increased in a given unit area. The anchoring screw of the invention also may be removed easily and conveniently to facilitate construction.

Abstract: A fast assembly structure module comprises a seat body connected to at least one control unit. The seat body has at least three plate bodies. Each plate body has a connection hole. The control unit has an arm. A retaining plate, which can be controlled to insert in and extract out of a corresponding connection hole, is controlled by the arm. The retaining plate is retracted by use of the arm. An electrical component having a plurality of projection sticks, each of which is removably inserted into the connection hole of one of the at least three plate bodies, is releasably locked to the seat body by the retaining plate and inserted into and removed from the seat body by using to arm to displace the retaining plate.

Abstract: Ratchet socket for fitting onto a screwed member. The ratchet socket is drivable by a tool to wrench the screwed member. The ratchet socket includes: a cylindrical main body formed with at least one internal circular hole and at least one through hole formed on the circumference of the main body and communicating with the circular hole; and a ratchet mechanism including a ratchet wheel rotatably disposed in the circular hole, a dog member movably accommodated in the through hole and a resilient hoop fitted around the main body to exert a resilient force onto the outer side of the dog member, keeping the dog member resiliently engaged with the ratchet wheel. When the dog member is engaged with the ratchet wheel, the ratchet mechanism provides a ratchet effect and the main body of the socket is one-way drivingly engaged with the ratchet wheel.