Abstract: An electronic power supply device is provided for light-emitting diodes (LEDs), which employs electronic control to maintain the LEDs within the rated ranges of current, voltage and temperature and provides the LEDs with extremely stable current, voltage and temperature. Meanwhile, the power supply device is effective in confining the LEDs within the rated ranges of voltage, current, and temperature so that the excellent electronics protection and design of logic device realized by the power supply device effectively overcomes aging/deterioration of LEDs caused by exceeding voltage and current and burning out due to exceeding temperature and also effectively pushes the rated current and voltage of a (low-power) LED module toward the maximum values to provide the greatest luminous efficiency for upgrading the applications of the LEDs to the primary grade of lighting.

Abstract: A MP3 loudspeaker system is disclosed. The MP3 loudspeaker system comprises a main loudspeaker and a sub loudspeaker connected by signal cables. The loudspeaker has a flat configuration and the edge of the loudspeaker is provided with magnetic element such that the main loudspeaker and the sub loudspeaker attract each other. The lower section of the main and sub loudspeaker is provided with a folding section and a signal cable connector. The loudspeaker can be folded and stand with the folding section as a support. The signal cable connector is also functioned as the base support for the loudspeaker.

Abstract: An electronic power supply device is provided for light-emitting diodes (LEDs), which employs electronic control to maintain the LEDs within the rated ranges of current, voltage and temperature and provides the LEDs with extremely stable current, voltage and temperature. Meanwhile, the power supply device is effective in confining the LEDs within the rated ranges of voltage, current, and temperature so that the excellent electronics protection and design of logic device realized by the power supply device effectively overcomes aging/deterioration of LEDs caused by exceeding voltage and current and burning out due to exceeding temperature and also effectively pushes the rated current and voltage of a (low-power) LED module toward the maximum values to provide the greatest luminous efficiency for upgrading the applications of the LEDs to the primary grade of lighting.

Abstract: A computer keyboard which includes a body portion, two loudspeakers mounted on the body portion, a microphone mounted on the body portion, a plurality of sockets mounted on the body portion, a switch mounted on the keyboard, a volume control mounted on the keyboard, a cable provided with a USB connector, a loudspeaker connector, a microphone connector, and a cable reel connected with the cable, whereby the computer keyboard can be used for converting electrical signals into sounds loud enough to be heard at a distance and converting sound waves into electrical energy thereby enabling the user to listen to the music and talk through the computer via the Internet.