Abstract: A battery charger having fixed ends for winding and releasing wires includes a box; an immovable axis provided at an inner wall of the box; a large turning wheel having a larger diameter and a small turning wheel having a smaller diameter disposed next to the large turning wheel, wherein the large and small turning wheels have a same center orifice flexibly connected into the immovable axis; and a wire having one end thereof penetrated through a through hole provided at the inner wall and further connected to the circuit board and winded in the large and small wire storage grooves. A wire is efficiently collected in the box, and thus making the wire of the battery charger spaceless for ready storage.

Abstract: A coaxial wire storage wheel devise includes a wire storage turning wheel having an uniform diameter, a center hole jointed to a uni-axial portion, and a wheel plane distinguished into left and right wheel planes; a spiral spring having a bottom end thereof connected to the axial portion and an outer end thereof connected to the wheel plane of the wire storage turning wheel; a communication wire fastened at the wheel plane to form upper and lower wires; and a right wall body having an inner wall plane fixed to the axial portion inserted through a left wall body, and a wire storage groove formed at the left and right wheel planes. The wire storage groove is for winding and storing the upper and lower wires, thereby releasing the upper wire at the turning wheel with equal length and distance as those of the lower wire being simultaneously released.

Abstract: An earphone wire winding box with coaxial and dual wheels has a communication wire, a big turning wheel with a longer outer diameter and a small turning wheel with a shorter outer diameter; both of the center holes thereof are respectively and lively jointed into an uni-axial portion; the wheel planes of the big and small turning wheels are respectively formed into storage grooves for the communication wire to coil around therein; when quite a length of the upper wire inside the storage groove of the big turning wheel is pulled out, the lower wire inside the storage groove of the small turning wheel descends only an extremely short distance, so that the earphone wire and the plug wire can be designed as one to eliminate any undesired connectional situation between them.

Abstract: A ceramic piezoelectric type microphone includes a lower cover and an upper cover, and a receiving space confined by the lower and upper covers when they are connected. A signal wire is led in the receiving space via an extension portion of the lower cover and passes through a substrate to connect to an electrical circuit board. The other side of the circuit board is connected to a piezoelectric ceramic plate. A high-density foam body is sandwiched between the piezoelectric ceramic plate and a securing portion on an inner side of the upper cover. When a ratio value of a diameter of the surface of the upper cover to a contact thickness formed by the upper cover is greater than 0.15, sound waves generated as a result of contact between cover surfaces and the user's throat skill pass through the foam body to the piezoelectric ceramic plate to be directly converted into a signal output, thereby eliminating most of the background noise except the sound of the user's voice.