Patent ID: 6141195
Filing Date: 2000-10-31
Classification: G08B,H02H

Abstract:
Apparatus for transmitting data and/or energy over a pair of conductors between a generator and a plurality of user stations in a communication system; said apparatus comprising a disconnect unit which includes a switch and a monitoring unit;said switch being connected to a first of said conductors so as to divide it into a first and a second conductor segment which are serially connected or disconnected via said switch depending on whether said switch is conductive or non-conductive, said switch being adapted when conductive to conduct current in either direction between said first and second segments of the first of said conductors;said disconnect unit further including a current limiting circuit element bridging said switch so as to provide a high ohmic level coupling path between said first and second conductor segments when said switch is non-conductive;said monitoring unit being connected to at least one of said conductor segments and being adapted to control said switch to become non-conductive when the potential of said one conductor segment falls below a first activation threshold and to become conductive again when the potential of said one conductor segment rises above a second activation threshold; andsaid monitoring unit comprises an FET connected in series between a second of said conductors and a control input of said switch, the gate of said FET being connected to one of said first and second segments of the first of said conductors.