Fault locating system for determining distance of fault on a transmission line from a predetermined position thereon

Claim 2

In a system for determining the location of a fault on a transmission line between a master station and a remote station, which fault produces a fault pulse that travels from the fault location to both stations, with the system having means for coupling pulses to and from the line at each station, the improvement comprising: in combination: a. first delay means for introducing a first delay of a predetermined period between the input and output thereof; having its input connected to said remote station and circuit means connecting the output thereof to said remote station, b. time interval means for measuring the time period between receipt of it of a first pulse and a second pulse, c. circuit means connected to receive pulses from said master station and having its output connected to said time interval means, said circuit means comprising second time delay means started by a fault pulse from said master station, said pulse resulting from a fault occurring in said transmission line, and travelling directly to the master station, and means for preventing said fault pulse from reaching said time interval means and permitting a generated pulse from said master station to reach said time interval means as the first pulse thereto, said generated pulse resulting from said fault pulse travelling directly from said fault and reaching said first delay means at said remote station as an input thereto, said generated pulse being generated at said remote station in response to an output from said first delay means and being transmitted through said transmissIon line to said master station, said second time delay means generating a pulse to said time interval means as the second pulse thereto a predetermined time after reception of said first pulse by said second time delay means, c-1. with the delay periods of said first and second delay means being selected such that the delay between the master station and said time interval means through said second delay means is at least as great as the delay between the master station and said time interval means through the line, the remote station and said first delay means, and c-2. with the time between arrival of the first and second pulses at said time interval means following occurrence of a fault being a function of the distance of the fault location from one of the stations.

Claim 3

A system as defined in claim 1, wherein said circuit means connecting the output of said first delay means to said remote station includes a pulse generator having the input thereof connected to the output of said first delay means and the output thereof connected to said remote station.

Claim 4

A system as defined in claim 1, wherein said means for preventing said first pulse from reaching said time interval means and for permitting a second pulse to reach said time interval means comprises control gate means having an input connected to said master station, an output connected to said time interval means, and an input connected to the output of said second time delay means, said second time delay means comprising means for generating a first pulse to said control gate means and thereafter said second pulse to said time interval means after reception of said fault pulse from said master station.

Claim 5

A system as defined in claim 3, wherein said second time delay means having the delay period for the generation of said pulse to said control gate means being selected such that the delay between the line remote station and said control gate means through said second delay means, bypassing said first delay means, is less than the delay between the line remote station and said control gate means through said first delay means, bypassing said second delay means.

Claim 6

A system as defined in claim 2, including: a. a test pulse generator for generating a test pulse simulating a fault pulse; b. circuit means for coupling a test pulse from said test pulse generator to the line master station; and c. means for actuating said test pulse generator to provide a test pulse after a second pulse is received at said time interval means.

Claim 7

A system as defined in claim 1, including: a. a test pulse generator for generating a test pulse simulating a fault pulse; b. circuit means for coupling a test pulse from said test pulse generator to the line master station; and c. means for actuating said test pulse generator to provide a test pulse after a second pulse is received at said time interval means.

Claim 8

A system as defined in claim 6 in which said means for actuating includes a third delay means having said second pulse as an input and providing an output to said test pulse generator a predetermined period after receiving said second pulse.

Claim 9

In a system for determining the location of a fault on a transmission line between a master station and a remote station, which fault produces a fault pulse that travels from the fault location to both stations, with the system having means for coupling pulses to and from the line at each station, the improvement comprising; in combination: a. time interval means for measuring the time period between receipt by it of a start pulse and a stop pulse, b. means for generating a start pulse in response to a fault pulse occurring in said transmission line and arriving at said remote station comprising first delay means having the input thereof connected to said remote station and generating an output pulse a predetermined time after reception of the input pulse from said remote station, c. telephone-type transmission line means having the input thereof coupled to the output of said first delay means and the output thereof coupled to said time interval means for transmission of the output pulse from said delay means to the time interval means as the start pulse therefor, d. means for generating a stop pulse in response to the fault pulse occurring in said transmission line and arriving at said master station comprising second delay means having the input thereof connected to said master station and generating an output pulse a predetermined time after reception of the input pulse from said master station, and e. means for coupling the output of said second delay means to said time interval means for coupling the output pulse from said second delay means to the time interval means as the stop pulse therefor, f. with the delay periods of said first and second delay means being selected such that the delay between the master station and said time interval means through said second delay means is at least as great as the delay between the master station and said time interval means through the line, the remote station and said first delay means, and g. with the time between arrival of the start and stop pulses at said time interval means following occurrence of a fault being a function of the distance of the fault location from one of the stations.

Claim 10

In a system for determining the location of a fault on a transmission line between a master station and a remote station, which fault produces a fault pulse that travels from the fault location to both stations, with the system having means for coupling pulses to and from the line at each station, the improvement comprising; in combination: a. time interval means for measuring the time period between receipt by it of a start pulse and a stop pulse, b. means for generating a start pulse in response to a fault pulse occurring in said transmission line and arriving at said remote station comprising first delay means having the input thereof connected to said remote station and generating an output pulse a predetermined time after reception of the input pulse from said remote station, c. telephone-type transmission line means having the input thereof coupled to the output of said first delay means and the output thereof coupled to said time interval means for transmission of the output pulse from said delay means to the time interval means as the start pulse therefor, d. means for generating a stop pulse in response to the fault pulse occurring in said transmission line and arriving at said master station comprising second delay means having the input thereof connected to said master station and generating an output pulse a predetermined time after reception of the input pulse from said master station, and e. means for coupling the output of said second delay means to said time interval means for coupling the output pulse from said second delay means to the time interval means as the stop pulse therefor, f. with the delay periods of said first and second delay means being selected such that the delay between the master station and said time interval means through said second delay means is at least as great as the delay between the master station and said time interval means through the line, the remote station and said first delay means, and g. with the time between arrival of the start and stop pulses at said time interval means following occurrence of a fault being a function of the distance of the fault location from one of the stations.

Claim 11

A system as defined in claim 8 in which said telephone-type transmission line is continuously connected between said first delay means and said time interval means.

Claim 12

A system as defined in claim 8 in which said telephone-type transmission line is intermittently connected between said first delay means and said interval means, and in which said system includes means for automatically dialing up a telephone-type transmission line after receiving a pulse at the line remote station.

Claim 13

A system as defined in claim 10 including: a. a test pulse generator for generating a test pulse simulating a fault pulse; b. circuit means for coupling a test pulse from said test pulse generator to the line master station; and c. means for actuating said test pulse generator to provide a test pulse after said second pulse is received at said time interval means.

Claim 14

A system as defined in claim 9 including: a. a test pulse generator for generating a test pulse simulating a fault pulse; b. circuit means for coupling a test pulse from said test pulse generator to the line master station; and c. means for actuating said test pulse generator to provide a test pulse after a second pulse is received at said time interval means.

Claim 15

In a system for determining the location of a fault on a transmission line between a master station and a remote station, which fault produces a fault pulse that travels from the fault location to both stations, with the system having means for coupling pulses to and from the line at each station, the improvement comprising in combination: a. first delay means for introducing a first delay of a predetermined period between the input and output thereof; b. second delay means for introducing second and third delays of predetermined periods between the inputs and outputs thereof, said third delay being greater than said second delay; c. time interval means for measuring the time period between receipt of a first pulse and a second pulse; d. circuit means for coupling a pulse from the line remote station to said first delay means as an input; e. circuit means for coupling a pulse from said first delay means to said time interval means as a first pulse including a pulse generator connected between said first delay means and the line remote station, the line itself, and a gate connected between the line master station and the time interval means, with said pulse generator providing a pulse for transmission along the line as the first pulse in response to an output pulse from said first delay unit, and with said control gate including means for blockiNg a fault pulse and passing said first pulse from the line master station to said time interval means; f. circuit means for coupling a pulse from the line master station to said second delay means as an input; g. circuit means for coupling a pulse from said second delay unit to said time interval unit as said second pulse, with the delay periods of said first and second delay means being selected such that the delay between the master station and said time interval means through said second delay means is at least as great as the delay between the master station and said time interval means through the line, the remote station and said first delay means, and with the time between arrival of the first and second pulses at said time interval unit following occurrence of a fault being a function of the distance of the fault location from one of the stations, and with said second delay means providing prior to the second pulse a control pulse for said gate permitting passage of a first pulse on receipt of the control pulse, with the delay period of said second delay unit for the control pulse being selected such that the delay between the line remote station and said gate through said second delay means, bypassing said first delay unit, is less than the delay between the line remote station and said control gate through said first delay means, bypassing said second delay means; h. a test pulse generator for generating a test pulse simulating a fault pulse; i. circuit means for coupling a test pulse from said test pulse generator to the line master station; and j. means for actuating said test pulse generator to provide a test pulse after said second pulse is received at said time interval means.

Claim 16

In a system for determining the location of a fault on a transmission line between a master station and a remote station, which fault produces a fault pulse that travels from the fault location to both stations, with the system having means for coupling pulses to and from the line at each station, the improvement comprising in combination: a. first delay means for introducing a first delay of a predetermined period between the input and output thereof; b. second delay means for introducing second and third delays of predetermined periods between the inputs and outputs thereof, said third delay being greater than said second delay; c. time interval means for measuring the time period between receipt of a first pulse and a second pulse; d. circuit means for coupling a pulse from the line remote station to said first delay means as an input; e. circuit means for coupling a pulse from said first delay means to said time interval means as a first pulse including a pulse generator connected between said first delay means and the line remote station, the line itself, and a gate connected between the line master station and the time interval means, with said pulse generator providing a pulse for transmission along the line as the first pulse in response to an output pulse from said first delay unit, and with said control gate including means for blockiNg a fault pulse and passing said first pulse from the line master station to said time interval means; f. circuit means for coupling a pulse from the line master station to said second delay means as an input; g. circuit means for coupling a pulse from said second delay unit to said time interval unit as said second pulse, with the delay periods of said first and second delay means being selected such that the delay between the master station and said time interval means through said second delay means is at least as great as the delay between the master station and said time interval means through the line, the remote station and said first delay means, and with the time between arrival of the first and second pulses at said time interval unit following occurrence of a fault being a function of the distance of the fault location from one of the stations, and with said second delay means providing prior to the second pulse a control pulse for said gate permitting passage of a first pulse on receipt of the control pulse, with the delay period of said second delay unit for the control pulse being selected such that the delay between the line remote station and said gate through said second delay means, bypassing said first delay unit, is less than the delay between the line remote station and said control gate through said first delay means, bypassing said second delay means; h. a test pulse generator for generating a test pulse simulating a fault pulse; i. circuit means for coupling a test pulse from said test pulse generator to the line master station; and j. means for actuating said test pulse generator to provide a test pulse after said second pulse is received at said time interval means.