Abstract: Methods, systems and locators for detecting faults in an insulation later of an insulated conductor buried beneath a ground surface are described. The locator comprises a magnetometer arranged to detect a magnetic field generated by the alternating current and to generate a current signal on the basis of the detected magnetic field, and an Alternating Voltage Gradient receiver comprising a pair of probes arranged to make electrical contact with the ground surface, which is arranged to generate a voltage signal indicative of a voltage between the pair of probes. A processor is configured to substantially synchronously sample the current signal and the voltage signal. This enables improved detection of faults in the insulation layer of the insulated conductor.

Abstract: Methods, systems and locators for detecting faults in an insulation layer of an insulated conductor buried beneath a ground surface are described. The locator comprises a magnetometer arranged to detect a magnetic field generated by the alternating current and to generate a current signal on the basis of the detected magnetic field, and an Alternating Voltage Gradient receiver comprising a pair of probes arranged to make electrical contact with the ground surface, which is arranged to generate a voltage signal indicative of a voltage between the pair of probes. A processor is configured to substantially synchronously sample the current signal and the voltage signal. This enables improved detection of faults in the insulation layer of the insulated conductor.

Abstract: Methods, systems and locators for detecting faults in an insulation layer of an insulated conductor buried beneath a ground surface are described. The locator comprises a magnetometer arranged to detect a magnetic field generated by the alternating current and to generate a current signal on the basis of the detected magnetic field, and an Alternating Voltage Gradient receiver comprising a pair of probes arranged to make electrical contact with the ground surface, which is arranged to generate a voltage signal indicative of a voltage between the pair of probes. A processor is configured to substantially synchronously sample the current signal and the voltage signal. This enables improved detection of faults in the insulation layer of the insulated conductor.

Abstract: An apparatus comprising a processor, at least one transceiver, a sensor configured to sense the presence of a user, wherein the processor is configured to cause the at least one transceiver to transmit information indicative of a user status only when the proximity sensor senses the presence of a user.

Abstract: An apparatus comprising a processor, at least one transceiver, a sensor configured to sense the presence of a user, wherein the processor is configured to cause the at least one transceiver to transmit information indicative of a user status only when the proximity sensor senses the presence of a user.

Abstract: A method of checking messages from a network of communication sources includes initially testing the signal strength of a plurality of communication sources, storing the identity of the communication sources with the two strongest signals, and alternatively entering a sleep mode and a wake-up mode, the wake-up mode synchronized to the communication source with the strongest signal. The method further includes testing the signal strength of one additional communication source, switching synchronization to the additional communication source if said source presents a signal stronger than the signal of a stored communication source with the strongest signal, and replacing the identity of any stored communication source if an additional communication sources tested in sequence presents a signal stronger than the signal of said stored communication source.

Abstract: A method of checking messages from a network of communication sources includes initially testing the signal strength of a plurality of communication sources, storing the identity of the communication sources with the two strongest signals, and alternatively entering a sleep mode and a wake-up mode, the wake-up mode synchronized to the communication source with the strongest signal. The method further includes testing the signal strength of one additional communication source, switching synchronization to the additional communication source if said source presents a signal stronger than the signal of a stored communication source with the strongest signal, and replacing the identity of any stored communication source if an additional communication sources tested in sequence presents a signal stronger than the signal of said stored communication source.

Abstract: A vehicle locating unit with improved power management. A receiver receives a signal from a network of communication sources. A signal strength monitoring subsystem determines which of the communication sources are transmitting the strongest signals. A power management subsystem is responsive to the signal strength monitoring subsystem and is configured to alternatively enter sleep and wake-up modes, synchronize the wake-up mode to the communication source transmitting the strongest signal, and test the signal strength of at least one additional communication source according to a predefined sequence.

Abstract: A vehicle locating unit with a receiver for receiving a signal from a network of communication sources, a transponder activated when a communication source sends a message to the receiver, and a power supply regulating circuit for regulating a nominal input voltage and powering the receiver and the transponder. A protection circuit is responsive to an injected input voltage and configured to clamp the injected (high level) input voltage at a predetermined maximum voltage.

Abstract: A vehicle locating unit with improved power management. A receiver receives a signal from a network of communication sources. A signal strength monitoring subsystem determines which of the communication sources are transmitting the strongest signals. A power management subsystem is responsive to the signal strength monitoring subsystem and is configured to alternatively enter sleep and wake-up modes, synchronize the wake-up mode to the communication source transmitting the strongest signal, and test the signal strength of at least one additional communication source according to a predefined sequence.

Abstract: A vehicle locating unit features a receiver which receives a signal from a network of communication sources and a transponder activated when a communication source sends a message to the receiver. There is a transmitter for sending signals to the communication sources and a proof of life subsystem configured to periodically send a proof of life message via the transmitter to the communication sources.

Abstract: A vehicle locating unit with a receiver for receiving a signal from a network of communication sources, a transponder activated when a communication source sends a message to the receiver, and a power supply regulating circuit for regulating a nominal input voltage and powering the receiver and the transponder. A protection circuit is responsive to an injected input voltage and configured to clamp the injected (high level) input voltage at a predetermined maximum voltage.

Abstract: In a method of timing a multi shot blast, a plurality of explosive charges each comprising a programmable detonator arrangement 14.1 to 14.n are positioned at a blast site. At a control center 11, the desired times of the shots in the blast are programmed into a transportable firing tool 13 and the tool is carried to each detonator arrangement where a dedicated data path is established between the tool and each detonator arrangement, one after the other. The charges are fired by loading data regarding the times on which the detonator arrangements must cause their associated charges to explode into each detonator arrangement, individually. The detonator arrangements are allowed to process the data and to cause their associated charges to explode when according to a clock in the detonator arrangement and the data stored in the arrangement it is time for the charge to explode.

Abstract: An electronic detonator system 10 comprises a remote RF transmitter 11 and a transportable housing 12 comprising means 13 for charging energy storage means in the detonator 15 and means 14 for programming delay time means in the detonator. The programming means 14 and charging means 13 are connected to a connector 26. Detonator 15 comprises an antenna 29, a RF receiver 30, programmable delay time means 32, a switch 33, a fuse 34 and energy storage means 35. The delay time means 32 and energy storage means 35 are connected to a connector 28. In use, connector 26 is connected to connector 28 at the blast site and storage device 35 is charged and delay time means 32 is programmed. A fire command signal is then transmitted by transmitter 11 and after the delay time, switch 33 connects storage means 35 to fuse 34 thereby to energize the fuse.

Abstract: A remote controllable electronic detonator and a method of detonating an explosive charge are disclosed and claimed. The detonator comprises an antenna 16, a RF receiver 15, an energy storage capacitor 17, a switch 18, a delay time circuit 21 and a fuse 19. The method comprises the steps of transmitting to the detonator, by means of transmitter 11, a wave comprising a carrier amplitude modulated by a low frequency modulating signal, receiving the wave and utilizing energy in the wave to charge capacitor 17, enabling switch 18 by increasing the frequency of the modulating signal and communicating, by means of the wave, a fire command signal to the detonator. After a predetermined time delay, switch 18 connects capacitor 17 to fuse 19 thereby to energize the fuse.