Fault finder

Claim 1

An electronic fault finder for identifying the location of a fault occurring along an electrical power transmission line coupled to a master unit and a geographically separated remote unit, comprising: fault detection circuit means at both the master unit and remote unit for distinguishing between background line noise and an incoming fault pulse, and for producing a logic fault signal at each unit in response to a detected fault pulse; master unit and remote unit clock means for providing constantly changing numerical output signals at the master unit and remote unit, respectively, the numerical output signals being representative of distance along the line; means operatively connected to the master unit clock means for modulating and transmitting clock signals over a communications line from the master unit clock means to the remote unit; means at the remote unit for demodulating clock signals received from the master unit and for synchronizing operation of the remote unit clock means to operation of the master unit clock means; master unit data means operatively connnected to the master unit fault detection circuit means and clock means for producing a binary output signal in response to a logic fault signal produced by the master unit fault detection circuit means, the binary output signal being representative of distance along the line from the master unit to the location of the fault; remote unit data means operatively connected to the remote unit fault detection circuit means and clock means for producing a binary output signal in response to a logic fault signal produced by the remote unit fault detection circuit means, the binary output signal being representative of distance along the line from the remote unit to the location of the fault; means operatively connected to the remote unit data means for modulating the binary output signals produced by it and transmitting the modulated signals to the master unit over the communications line; means for demodulating signals received by the master unit; and microprocessor means at the master unit for processing both the binary output signals produced by the master unit data means and the binary output signals transmitted from the remote unit data means to produce a distance output value representative of the location of a fault along the line.

Claim 5

A method for identifying the location of a fault occurring along an electrical power transmission line coupled to a master unit and a geographically separated remote unit, comprising the following steps: monitoring all wave forms other than line frequency at both the master unit location and at the remote unit location; discriminating between fault surges and repetitive background line noise levels at each unit; developing a logic fault signal at each unit in response to a detected fault pulse; synchronizing a remote unit clocking system with operation of a similar master unit clocking system by modulating signals produced by the master unit clocking system and transmitting the modulated signals over a conventional communication line for demodulation at the remote unit; producing a binary output signal at the master unit in response to a logic fault signal, the binary output signal being representative of distance along the line from the master unit to the location of the fault; producing a binary output signal at the remote unit in response to a logic fault signal, the binary output signal being representative of distance along the line from the remote unit to the location of a fault; transmitting a modulated binary output signal from the remote unit to the master unit over the communication line for demodulation and storage at the master unit; and electronically processing the binary output signals to produce a distance output value representative of the location of the fault along the line.

Claim 6

A method for identifying the location of a fault occurring along an electrical power transmission line coupled to a master unit and a geographically separated remote unit, comprising the following steps: monitoring all wave forms other than line frequency at both the master unit location and at the remote unit location; discriminating between fault surges and repetitive background line noise levels at each unit; developing a logic fault signal at each unit in response to a detected fault pulse; synchronizing a remote unit clocking system with operation of a similar master unit clocking system by modulating signals produced by the master unit clocking system and transmitting the modulated signals over a conventional communication line for demodulation at the remote unit; producing a binary output signal at the master unit in response to a logic fault signal, the binary output signal being representative of distance along the line from the master unit to the location of the fault; producing a binary output signal at the remote unit in response to a logic fault signal, the binary output signal being representative of distance along the line from the remote unit to the location of a fault; transmitting a modulated binary output signal from the remote unit to the master unit over the communication line for demodulation and storage at the master unit; and electronically processing the binary output signals to produce a distance output value representative of the location of the fault along the line.