| 摘要 |
PURPOSE: A timer having an alarm function is provided to generate alarm signals if the user uses the PC over the preset time. CONSTITUTION: The device comprises an input terminal, an output consent, a display, a time setter(10), an output consent sensor(13), an output current sensor(14), and an alarm sound generator(15). The input terminal connects to an external power supply. The output consent, connected to the input terminal, supplies the electric power for a PC. The display displays a usable time span and a current time. The time setter(10) sets or modifies the usable time span or the current time. The output consent sensor(13) senses whether a PC power plug is detached from the output consent. The output current sensor(14) senses the current flowing between the output consent and the input terminal. The alarm sound generator(15) generates the alarm sound if the set usable time has passed and the current between the output consent and the input terminal is sensed by the sensor(14).
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