Abstract: An electro-acoustical transducer device is disclosed, which includes: a hollow disk body that generally defines an axis of propagation, the hollow disk body comprising: a pair of plate members extending substantially perpendicular to the axis of propagation, each provided with a central transmitting port arranged about the axis of propagation, and a peripheral enclosure jointing the pair of plate members at the respective outer edge portions thereof, thereby defining a chamber of resonance between the pair of plate members; wherein a ring-opening about the axis of propagation that enables access to the chamber of resonance is formed between the central transmitting ports of the plate members.

Abstract: A power saving type vehicle socket apparatus includes a housing, a circuit board, a power conversion circuit, a power socket, a magnetic switch, a shroud and a magnetic object. The housing includes a tube opening. The shroud includes a cap. When the cap caps the tube opening of the housing, the magnetic switch senses the magnetic object to generate a first signal to send the first signal to the power conversion circuit, so that the power conversion circuit stop supplying power to the power socket. When the cap does not cap the tube opening of the housing, the magnetic switch does not sense the magnetic object, so that the magnetic switch generates a second signal to send the second signal to the power conversion circuit, so that the power conversion circuit supplies power to the power socket.

Abstract: A detachment-prevention vehicle socket includes a housing (1) and an electrode body (3) installed in the housing (1). The electrode body (3) includes a movable element (31) and a resilient sleeve (32). A rotatable ring (2) is in contact with the housing (1) and is threadedly fastened to the movable element (31), so rotation of the rotatable ring (2) can drive the movable element (31) and the resilient sleeve (32) to move axially inwardly of the housing (1) and thereby clamp a cigarette lighter plug (B1) inserted in the resilient sleeve (32). Accordingly, the cigarette lighter plug (B1) can be stably fixed in the resilient sleeve (32) without loosening.

Abstract: A detachment-prevention vehicle socket includes a housing (1) and an electrode body (3) installed in the housing (1). The electrode body (3) includes a movable element (31) and a resilient sleeve (32). A rotatable ring (2) is in contact with the housing (1) and is threadedly fastened to the movable element (31), so rotation of the rotatable ring (2) can drive the movable element (31) and the resilient sleeve (32) to move axially inwardly of the housing (1) and thereby clamp a cigarette lighter plug (B1) inserted in the resilient sleeve (32). Accordingly, the cigarette lighter plug (B1) can be stably fixed in the resilient sleeve (32) without loosening.