Dual sourcing power over ethernet on a single data path

A method for providing direct current (DC) power using a power-over-Ethernet (PoE) protocol in an HDBase T data communication system, comprising:

• installing at least two powered devices (PDs) adapted to communicate with each other using a first and second Ethernet data path (EDP) and further adapted to receive DC power using a PoE protocol and the first and second EDPs;
• and
• installing a mid-span power injection device (MSPID) between the at least two PDs, wherein
• the MSPID is adapted to provide a first DC power to a first of the at least two PDs using the PoE protocol and the first EDP and without the first DC power being provided to a second of the at least two PDs, and wherein
• the MSPID is further adapted to provide a second DC power to the second PD using the PoE protocol and the first EDP and without the second DC power being provided to the first PD, and further wherein,
• data communications can occur between the first and second PDs using the first EDP that provides respective DC power to each of the first and second PDs, wherein
• each of the first and second EDPs comprises
• one pair of twisted wires, each of the twisted wires of the one pair of twisted wires including a first portion and a second portion, each of the first and second portions including a first end connected to a respective PD, and each of the first and second portions further including a second end, and
• a pair of capacitors, each capacitor connecting the first and second portions of a respective wire together at the second end of the first and second portions.

A data communication system using power over Ethernet (PoE) for power distribution, comprising:

• a first and second powered device (PD), each of which is adapted to communicate with each other through a first and second Ethernet data path (EDP), and wherein each of which is further adapted to receive direct current (DC) power using a PoE protocol;
• and
• a mid-span power injection device (MSPID) adapted to provide a bi-directional communications interface between the first and second PDs using the first and second EDPs, and wherein
• the MSPID is further adapted to
• provide a first set of DC power to the first PD using the first and second EDP, and to
• provide a second set of DC power to the second PD using the first and second EDP, and to
• substantially prevent the first set of DC power from reaching the second PD, and to
• substantially prevent the second set of DC power from reaching the first PD, wherein
• each of the first and second EDPs comprises
• one pair of twisted wires, each of the twisted wires of the one pair of twisted wires including a first portion and a second portion, each of the first and second portions including a first end connected to a respective PD, and each of the first and second portions further including a second end, and
• a pair of capacitors, each capacitor connecting the first and second portions of a respective wire together at the second end of the first and second portions.

A data communication system using power over Ethernet (PoE) for power distribution, comprising:

• a first data path comprising a single pair of twisted wires,
• each of the twisted wires comprising a first portion and a second portion,
• each of the first and second portions of the twisted wires comprising a first terminal and a second terminal;
• a first powered device and a second powered device (PD), each of which is adapted to communicate with each other through the first data path, and each of which are further adapted to receive direct current (DC) power;
• a first power supply adapted to provide a first direct current (DC) power;
• a second power supply adapted to provide a second DC power;
• a pair of capacitors;
• and
• a pair of inductors, wherein
• a first terminal of a first inductor is connected to the first portion of a first wire of the twisted wires,
• a second terminal of the first inductor is connected to the first portion of a second wire of the twisted wires,
• a first terminal of a second inductor is connected to the second portion of the first wire of the twisted wires,
• a second terminal of the second inductor is connected to second portion of the second wire of the twisted wires, and wherein
• a first terminal of a first capacitor is connected to a second terminal of a first portion the first wire of the twisted wires,
• a second terminal of the first capacitor is connected to a second terminal of a second portion of the first wire of the twisted wires,
• a first terminal of a second capacitor is connected to a second terminal of a first portion of the second wire of the twisted wires,
• a second terminal of the second capacitor is connected to a second terminal of the second portion of the second wire of the twisted wires, and wherein
• a first terminal of the first portion of the first wire is connected to a first DC power receiving terminal of the first powered device,
• a first terminal of the first portion of the second wire is connected to a second DC power receiving terminal of the first powered device,
• a first terminal of the second portion of the first wire is connected to a first DC power receiving terminal of the second powered device,
• a first terminal of the second portion of the second wire is connected to a second DC power receiving terminal of the second powered device, and wherein
• the first power supply is adapted to provide a first DC power through the first inductor to the first powered device,
• the second power supply is adapted to provide a second DC power through the second inductor to the second powered device,
• the first power supply is substantially prevented from supplying first DC power to the second powered device by the first and second capacitor,
• the second power supply is substantially prevented from supplying second DC power to the first powered device by the first and second capacitor, and
• the first and second powered devices can communicate to each other through the first data path.