Abstract: The present invention discloses an apparatus and a method for determining the voltage level of a first signal from a playback device having an interface in compliance with an industrial standard. According to the method, first receive the first signal by a signal receiving pin electrically coupled to a signal transmitting pin of the interface. Then output a first output voltage by processing the first signal by the combination of a first zener diode and a first transistor and a second output voltage by processing the first signal by the combination of a second zener diode and a second transistor. Thus the voltage level of the first signal can be determined according to the first output voltage and the second output voltage.

Abstract: The present invention discloses an apparatus and a method for determining the voltage level of a first signal from a playback device having an interface in compliance with an industrial standard. According to the method, first receive the first signal by a signal receiving pin electrically coupled to a signal transmitting pin of the interface. Then output a first output voltage by processing the first signal by the combination of a first zener diode and a first transistor and a second output voltage by processing the first signal by the combination of a second zener diode and a second transistor. Thus the voltage level of the first signal can be determined according to the first output voltage and the second output voltage.

Abstract: A network switching apparatus for supplying power to network communication equipment through a twisted pair line comprising a power control circuit having a plurality of sockets, each socket connected with a RJ-45 connector so as to electrically connect the switching apparatus to a corresponding socket of the communication equipment through the twisted pair line of RJ-45 connector, and having the ability to identify, in accordance with specifications stipulated in IEEE 802.3af, whether the communication equipment has the capability of receiving power from each socket through the twisted pair line prior to supplying power to the communication equipment.

Abstract: A network switching apparatus for supplying power to network communication equipment through a twisted pair line comprising a power control circuit having a plurality of sockets, each socket connected with a RJ-45 connector so as to electrically connect the switching apparatus to a corresponding socket of the communication equipment through the twisted pair line of RJ-45 connector, and having the ability to identify, in accordance with specifications stipulated in IEEE 802.3af, whether the communication equipment has the capability of receiving power from each socket through the twisted pair line prior to supplying power to the communication equipment.