Power over ethernet emergency lighting system and method of detecting power loss of a link segment thereof
View Patent ↗A system for providing power over Ethernet emergency lighting is disclosed. The system includes a rechargeable battery pack that is charged without interfering with data signals present on a power over Ethernet link that provides normal lighting. The system includes a power loss monitor for monitoring the presence of normal lighting power present on a power over Ethernet link without interference.
1. A power over Ethernet (POE) emergency lighting system comprising:
a POE input configured to connect to a POE port link segment, the POE input connected to a POE interface, which extracts a DC power from a connected POE port link segment and supplies the DC power to a normal lighting lamp driver and an auxiliary DC output;
a rechargeable battery configured to receive the DC power from the auxiliary DC output;
a power loss monitor configured to detect a loss of normal operating power, and
a switch having a first input connected to the rechargeable battery, a second input connected to the normal lighting lamp driver and an output, wherein
when the system has normal operating power, the switch's output is connected to the normal lighting lamp driver, and when the power loss monitor detects a loss of normal operating power, the switch's output is connected to the rechargeable battery.
2. The system of claim 1 , wherein the power loss monitor is configured to monitor the loss of normal operating power by monitoring a loss of power of DC power supplied at the auxiliary DC output.
3. The system of claim 2 , further including a DC power interface converter for receiving the DC power from the auxiliary DC output.
4. The system of claim 3 , wherein the power loss monitor is connected to the DC power interface converter.
5. The system of claim 2 , wherein the DC power interface converter is connected between the rechargeable battery and the auxiliary DC output.
6. The system of claim 2 , further comprising a controller configured to receive an indication of a power down condition from the power loss monitor and to direct the switch to switch between its first and second inputs depending on whether DC power is present on the connected POE port link segment.
7. The system of claim 1 , further comprising a battery charger configured between the auxiliary DC output and the rechargeable battery.
8. The system of claim 1 , further comprising a backup lighting LED driver configured between the rechargeable battery and the first input of the switch.
9. The system of 7 , further comprising one or more LED lamps connected to the output of the switch.
10. The system of claim 1 , wherein the switch is one of a solid-state switch or an electromechanical switch.
11. The system of claim 1 , wherein the POE interface supplies no more than 3W to the auxiliary DC output.