A remote power feed device for supplying a remote power feed to a terminal in a telecommunication network includes a first resistor and a second resistor in parallel with the first resistor and having a lower resistance than the first resistor. It compares the voltage at the terminal of the first resistor...http://www.google.com.hk/patents/US20020091951?utm_source=gb-gplus-share專利 US20020091951 - Device for remote power feeding a terninal in a telecommunication network, and a concentrator and a repreater including the device
