Abstract: An initiative warning system comprises a protective area for accommodating objects and defining an area network, a plurality of sensors respectively installed on the objects, a detecting mainframe connected with the area network, and a terminal communicated with the detecting mainframe through the area network. Wherein, the arrangement of the area network promotes the connection between the detecting main frame and substitutes the conventional wiring allocation, so as to streamline installations of the detecting mainframe and the sensors. Additionally, the sensors can regularly transmit oscillating signals to the detecting mainframe for a further recognition and comparison. Thus, a controlling signal would be timely sent to trigger a warning command showing on the terminal through the area network when the compatible signals between the sensors and the detecting mainframe are not detected by the detecting mainframe, thereby preferably attaining an active warning effect.

Abstract: An initiative warning system comprises a protective area for accommodating objects and defining an area network, a plurality of sensors respectively installed on the objects, a detecting mainframe connected with the area network, and a terminal communicated with the detecting mainframe through the area network. Wherein, the arrangement of the area network promotes the connection between the detecting main frame and substitutes the conventional wiring allocation, so as to streamline installations of the detecting mainframe and the sensors. Additionally, the sensors can regularly transmit oscillating signals to the detecting mainframe for a further recognition and comparison. Thus, a controlling signal would be timely sent to trigger a warning command showing on the terminal through the area network when the compatible signals between the sensors and the detecting mainframe are not detected by the detecting mainframe, thereby preferably attaining an active warning effect.

Abstract: An initiative alarm system mainly comprising a first alarm device and a second alarm device; said first alarm device continuously or alternately transmitted an encoded signal within a certain frequency. In the other hand, said second alarm device includes a receiver for receiving the signal, a CPU for decoding the signal and determining the correctness of received signal, and a siren interconnected with CPU and trigged when the signal is fail to be received or fail to be received within certain frequency. Said second alarm device is hand-hold by a guardian and said first alarm device is carried by a protective object so as when the first alarm device is kept away beyond the certain distance. The signals will be transmitted immediately, and then, the siren is simultaneously triggered.

Abstract: An automatic erasing device is used for erasing chalk marks on a writing board, and includes an erasing mechanism having an elongated housing disposed frontwardly of and slidable relative to the writing board along a longitudinal axis. The housing extends in a transverse axis relative to the longitudinal axis, and has a rear wall formed with an elongated rear opening to confront the writing board, and a lower portion formed with a water tank. An eraser unit is disposed within the elongated housing, and is biased to protrude outwardly and rearwardly of the rear wall via the elongated rear opening for abutting against the writing board. The eraser unit is connected to the water tank in such a manner that water flows from the water tank into the eraser unit so as to soak the eraser unit while the eraser unit moves on the writing board.