摘要 |
<p>The device described is used to inspect and detect faults in electrical or telephone lines (3, 4). It comprises an inspection system and an alarm system at one end of the line and another associated system at the other end. The associated system comprises a trip-switch (i), an impedance (9, 10), and a diode (8) which rectifies the line supply. Current polarisation may be achieved by a circuit (13) in equilibrium when the normal electrical contact is open. One arm of this circuit comprises the diode's impedance (8) the condenser (9) and a resistance (10).</p> |