Abstract: A protective cover for a network cable socket is disclosed. The protective cover is moveably connected to the network cable socket. The protective cover of the network cable socket comprises a housing and two elastic sheets. The housing is moveably connected to the network cable socket. Each of the elastic sheets includes a fixing portion, an extension arm, a stopper and a guiding ramp. The two extension arms are connected to the two fixing portions, respectively. The two fixing portions are fixed to two sides of the housing, respectively. The two stoppers and the two guiding ramps are formed at the two extension arms, respectively. A distance between the two guiding ramps is larger than the distance between the two stoppers.

Abstract: An audio interface circuit including a processor, an audio jack, a first filter circuit, a second filter circuit, a first clamp circuit, a second clamp circuit, a third filter circuit, and a fourth filter circuit is provided. A first clamp circuit and a second clamp circuit between a third and fourth electrodes and a processor, so that the third and fourth electrodes are allowed to be coupled to a microphone.

Abstract: An alarm device applied to a portable electronic device is provided. The alarm device includes a detection unit and a connecting unit. The detection unit includes a first data transfer pin, and the first transfer pin is preset to a first electric potential. When the portable electronic device is connected to the detection unit via the connecting unit, the first data transfer pin is connected to a second electric potential via the connecting unit. The detection unit is set in a detection mode. In the detection mode, when electric potential of the first data transfer pin is switched from the second electric potential to the first electric potential, the detection unit issues an alarm.

Abstract: An audio interface circuit including a processor, an audio jack, a first filter circuit, a second filter circuit, a first clamp circuit, a second clamp circuit, a third filter circuit, and a fourth filter circuit is provided. A first clamp circuit and a second clamp circuit between a third and fourth electrodes and a processor, so that the third and fourth electrodes are allowed to be coupled to a microphone.

Abstract: A protective cover for a network cable socket is disclosed. The protective cover is moveably connected to the network cable socket. The protective cover of the network cable socket comprises a housing and two elastic sheets. The housing is moveably connected to the network cable socket. Each of the elastic sheets includes a fixing portion, an extension arm, a stopper and a guiding ramp. The two extension arms are connected to the two fixing portions, respectively. The two fixing portions are fixed to two sides of the housing, respectively. The two stoppers and the two guiding ramps are formed at the two extension arms, respectively. A distance between the two guiding ramps is larger than the distance between the two stoppers.

Abstract: An alarm device applied to a portable electronic device is provided. The alarm device includes a detection unit and a connecting unit. The detection unit includes a first data transfer pin, and the first transfer pin is preset to a first electric potential. When the portable electronic device is connected to the detection unit via the connecting unit, the first data transfer pin is connected to a second electric potential via the connecting unit. The detection unit is set in a detection mode. In the detection mode, when electric potential of the first data transfer pin is switched from the second electric potential to the first electric potential, the detection unit issues an alarm.