Abstract: A vehicle power management system and a power management method thereof are provided. The power management method includes: determining, by a microcontroller, whether or not a voltage of an ignition-off signal is less than a voltage threshold when the microcontroller receives the ignition-off signal; stopping a vehicle power supply from charging a backup battery, and using the vehicle power supply to charge a back-end load; activating a counter of the microcontroller; stopping the vehicle power supply from charging the back-end load, and using the backup battery to charge the back-end load when a counting time of the counter reaches a first time threshold; sending, by the microcontroller, the ignition-off signal to the back-end load when the counting time of the counter reaches a second time threshold; and stopping the backup battery from charging the back-end load when the counting time of the counter reaches a third time threshold.

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: The present disclosure provides a polyimide resin having at least two glass transition temperatures measured by dynamic mechanical analysis (DMA). Also, a metal-clad laminate including the polyimide resin.

Abstract: The present disclosure provides a polyimide resin having at least two glass transition temperatures measured by dynamic mechanical analysis (DMA). Also, a metal-clad laminate including the polyimide resin.