Abstract: An electrical fault detector is shown for installation in electrical network (101) of the type comprising a first voltage source (104) and a second voltage source (107), each of which have a respective positive rail (105,108) connected by a positive concentrator (110) and a respective negative rail (106,109) connected by a negative concentrator (111). The detector comprises an inductor (112) for location in one of: the positive concentrator between the connections of the positive rails thereto, and the negative concentrator between the connections of the negative rails to thereto. The detector also comprises a fault identification device (113) configured to monitor the voltage across the inductor, and generate a fault signal in response to the voltage across the inductor exceeding a threshold.

Abstract: An electrical fault detector is shown for installation in electrical network (101) of the type comprising a first voltage source (104) and a second voltage source (107), each of which have a respective positive rail (105,108) connected by a positive concentrator (110) and a respective negative rail (106,109) connected by a negative concentrator (111). The detector comprises an inductor (112) for location in one of: the positive concentrator between the connections of the positive rails thereto, and the negative concentrator between the connections of the negative rails to thereto. The detector also comprises a fault identification device (113) configured to monitor the voltage across the inductor, and generate a fault signal in response to the voltage across the inductor exceeding a threshold.

Abstract: A method of determining the location of a fault within a first inductive part of an electrical circuit, including a voltage source, first inductive part and second inductive part. A shortened circuit created by the fault includes the voltage source, a portion of the first inductive part and the second, connected in series. The fault occurs across first and second points in the first inductive part. The length of first inductive part between a positive terminal and first point is substantially equal to the length of first inductive part between a negative terminal and second point. The voltage source supplies a known voltage Vs when the fault occurs and the second inductive part has a known inductance L2 when the fault occurs. The method takes advantage of the initial transient response of the circuit to determine the inductance of the portion of the first inductive part in the shortened circuit.

Abstract: A method of determining the location of a fault within a first inductive part of an electrical circuit, including a voltage source, first inductive part and second inductive part. A shortened circuit created by the fault includes the voltage source, a portion of the first inductive part and the second, connected in series. The fault occurs across first and second points in the first inductive part. The length of first inductive part between a positive terminal and first point is substantially equal to the length of first inductive part between a negative terminal and second point. The voltage source supplies a known voltage Vs when the fault occurs and the second inductive part has a known inductance L2 when the fault occurs. The method takes advantage of the initial transient response of the circuit to determine the inductance of the portion of the first inductive part in the shortened circuit.

Abstract: An interactive test preparation platform that provides test problems and solutions in an interactive and enhanced manner. For example, the platform can provide an interactive problem and solution user interface that presents solution notations across different selectable problem screens in a manner that enhances the user's understanding of the problem and solution. The platform can enable the user to launch via the user interface multiple videos that explain the solutions to a particular problem in an efficient and bandwidth sensitive manner. The platform can also provide a navigation user interface that enables a user to locate items of interest in a quick and efficient manner by dynamically ordering the items in response to a selected item characteristic.