There is disclosed herein a fault-tolerant memory organization which permits through the incorporation of redundancy the utilization of circuit chips having defective sections. The apparatus involves the use of redundant sections fabricated on the chip in conjunction with a data relocation technique. The relocation scheme utilizes a code-decode arrangement which inserts zeros into the data stream to avoid the defective sections and provides a zero delete arrangement when the previously coded inf...

A fault current protection switch detects fault currents from conductors of a supply means to ground. The system uses at least one difference transformer connected to the conductors of the supply mains. An oscillation generator circuit is connected to the difference transformer through feedback windings. The oscillation generator circuit checks the magnetization of a core of the difference transformer, and, in the event of a change in the transforming properties of the core due to "mis" magnetiz...

A fault-tolerant clock system for providng digital timing signals (system clock signals) is provided by a plurality of clock sources. Each clock source receives as inputs the generated clock signals from all the other clock sources and contains receiver circuitry to derive a system clock signal from said clock sources which is the consensus clock signals of the other sources. Each clock source generates and distributes to the other clock sources a clock signal which is phase locked to the derive...

Apparatus provides for testing a fault indicator of the type which has a surge-current detection portion and a settable fault indicating portion and which is widely used in electric power distribution systems. Such a fault indicator must meet certain performance specifications including a maximum allowable reaction-time specification relating to the time required for the detection portion first to detect a surge current flowing in a conductor as a result of a down-line fault and then to set the ...

The present invention comprises computer system equipment useful for detection of faults in data transmission within a computer system. Fault detection is accomplished by monitoring the current flow through a digital signal source means, which is characterized in that it only draws significant current during a non-transition period when a fault condition occurs.

An error detection circuit detects prolonged sequences of unchanged logic state in a data busing structure. The circuit generates a complementary two rail logic output from a pair of flip-flops. The circuit includes a comparator which compares the logic state of the data input from the bus with the output of one of the flip-flops, and which inputs alternate opposite logic states to that flip-flop as long as the data input exists for a time in the same logic state as the output of the one flip-fl...

A device for sensing current flow in an electric conductor employs a ferromagnetic core coupled to the conductor and a control winding on the core for applying a periodic magnetic flux to a part of the core of a magnitude to vary the core permeability, preferably driving a part of the core in and out of saturation. The periodic flux interrupts any flux circulating in the core due to current flow in the conductor. An output winding on the core has a signal voltage induced therein whose amplitude ...

A circuit breaker panel system supplies power to plural circuits that are ground fault protected and plural circuits that are not ground fault protected. The panel system has two sections. One section, which is not ground fault protected, contains a ground fault circuit breaker that supplies power to the second section, so that the entire second section is ground fault protected.

A fault diagnosis system which detects possible faulty components in a complex system. The complex system is represented by a representation comprising a plurality of nodes interconnected by links defining a flow among nodes corresponding to flows in the complex system. At least one of the nodes is a checkpoint node, which generates a report if the flow received by it is not correct. A fault diagnosis processor performing upstream search operation to repeatedly (such as by recursion of iteration...

A hand-held ground fault interrupter for checking the operation of a ground fault protected wall receptacle. The blades of an electrical terminal protrude from one end of a housing which contains a potentiometer and electrical connecting means between the potentiometer and the blades. The tester creates a ground fault by allowing current to leak to the ground path, the amount of leakage varied by the potentiometer. A properly operating ground fault interrupter senses the leakage and is designed ...