公开(公告)号：EP0706663B2

公开(公告)日：2003-11-12

申请号：EP94918977.3

申请日：1994-06-30

申请人： Avo International Limited

发明人： GURR, David, James

IPC分类号： G01R31/42 ,  G01R27/16

CPC分类号： H03H19/002 ,  G01R31/42

公开(公告)号：EP0706663B1

公开(公告)日：1997-10-01

申请号：EP94918977.3

申请日：1994-06-30

申请人： Avo International Limited

发明人： GURR, David, James

IPC分类号： G01R31/42 ,  G01R27/16

CPC分类号： H03H19/002 ,  G01R31/42

摘要： In an electrical test instrument for determining a loop impedance in a circuit breaker protected AC circuit, a test current of less than the circuit breaker trigger current is supplied to the circuit and the test voltage which develops due to the test current is isolated and detected. For testing a 240 volts 50 Hertz mains supply circuit, the test instrument includes a two-path cross synchronised filter (4) which rejects the 240 volts mains signal to isolate the test voltage signal to enable an accurate determination of the loop impedance to be made.

公开(公告)号：EP0706663A1

公开(公告)日：1996-04-17

申请号：EP94918977.0

申请日：1994-06-30

申请人： Avo International Limited

发明人： GURR, David, James

IPC分类号： G01R31 ,  H03H19

CPC分类号： H03H19/002 ,  G01R31/42

摘要： In an electrical test instrument for determining a loop impedance in a circuit breaker protected AC circuit, a test current of less than the circuit breaker trigger current is supplied to the circuit and the test voltage which develops due to the test current is isolated and detected. For testing a 240 volts 50 Hertz mains supply circuit, the test instrument includes a two-path cross synchronised filter (4) which rejects the 240 volts mains signal to isolate the test voltage signal to enable an accurate determination of the loop impedance to be made.