The present disclosure relates to an insulation resistance measuring device and method, including a parameter resistance connected to a negative electrode terminal of a battery; a shunt resistance connectable to the parameter resistance; a current detection circuit including an operational amplifier configured to detect and output voltage between both ends of the shunt resistance; and a control unit configured to determine the insulation resistance of the battery using a switch control terminal configured to control a switch connected between the parameter resistance and the shunt resistance to an ON or OFF state, a detection signal output terminal configured to selectively apply a first high voltage signal and a first low voltage signal to the shunt resistance, a control signal output terminal configured to apply a control voltage signal to the operational amplifier to adjust an output voltage of the operational amplifier within a predetermined range, an ADC connected to an output terminal of the operational amplifier, and a predefined insulation resistance formula that includes, as a parameter, a first voltage change amount with respect to the output voltage of the operational amplifier being measured through the ADC when the first high voltage signal and the first low voltage signal are applied to the shunt resistance.

The present disclosure relates to an insulation resistance measuring device and method, including a parameter resistance connected to a negative electrode terminal of a battery; a shunt resistance connectable to the parameter resistance; a current detection circuit including an operational amplifier configured to detect and output voltage between both ends of the shunt resistance; and a control unit configured to determine the insulation resistance of the battery using a switch control terminal configured to control a switch connected between the parameter resistance and the shunt resistance to an ON or OFF state, a detection signal output terminal configured to selectively apply a first high voltage signal and a first low voltage signal to the shunt resistance, a control signal output terminal configured to apply a control voltage signal to the operational amplifier to adjust an output voltage of the operational amplifier within a predetermined range, an ADC connected to an output terminal of the operational amplifier, and a predefined insulation resistance formula that includes, as a parameter, a first voltage change amount with respect to the output voltage of the operational amplifier being measured through the ADC when the first high voltage signal and the first low voltage signal are applied to the shunt resistance.

An electrical activity sensor attachable to a power cable of an electrical device for detecting an impulse generated in the power cable in response to a change in electrical power state of the electrical device is described. The electrical activity sensor has an antenna assembly including an antenna element operable to magnetically couple with an electrical pulse generated in the power cable, to induce an electrical signal, in response to a change in electrical power state of the electrical device and to wirelessly transmit data representative of the electrical power state change of the electrical device to a remote reader device. The antenna element is a helical shape dipole having at least one turn arranged, in use, around the power cable.

A method for detection of a failure of a protective fuse used to protect an associated load against overcurrent and/or against overload, wherein the method includes the steps of: measuring an electrical current, flowing through the protective fuse to the load by means of a current sensor element, determining a thermal energy generated in the protective fuse depending on the measured electrical current, and automatically detecting a failure of the protective fuse if the determined thermal energy exceeds a predetermined threshold value and if the electrical current, measured by the current sensor element has stopped flowing through said protective fuse.

A method for detection of a failure of a protective fuse used to protect an associated load against overcurrent and/or against overload, wherein the method includes the steps of: measuring an electrical current, flowing through the protective fuse to the load by means of a current sensor element, determining a thermal energy generated in the protective fuse depending on the measured electrical current, and automatically detecting a failure of the protective fuse if the determined thermal energy exceeds a predetermined threshold value and if the electrical current, measured by the current sensor element has stopped flowing through said protective fuse.

A state detection apparatus includes a communication circuit that transmits information to an external apparatus, a control circuit that operates the communication circuit at a first timing, a battery that supplies electric power to the communication and control circuits, and a first explosion-proof barrier connected between a contact circuit and the control circuit. The control circuit applies a test signal, generated based on voltage from the battery, to the contact circuit at a second timing arriving at shorter intervals than the first timing, acquires a detection signal indicating current flow in the contact circuit due to test signal application, and regardless of the first timing, operates the communication circuit when the detection signal is acquired to transmit to the external apparatus that the state of a device connected to the contact circuit is abnormal.

A state detection apparatus includes a communication circuit that transmits information to an external apparatus, a control circuit that operates the communication circuit at a first timing, a battery that supplies electric power to the communication and control circuits, and a first explosion-proof barrier connected between a contact circuit and the control circuit. The control circuit applies a test signal, generated based on voltage from the battery, to the contact circuit at a second timing arriving at shorter intervals than the first timing, acquires a detection signal indicating current flow in the contact circuit due to test signal application, and regardless of the first timing, operates the communication circuit when the detection signal is acquired to transmit to the external apparatus that the state of a device connected to the contact circuit is abnormal.

A current sensor is configured to detect a current flowing through an electrical conductor. The current sensor includes a core and a coil wound around the core. The core has a hollow therein configured to allow the electrical conductor to pass through the hollow. The core substantially has a C-shape having a gap connected to the hollow. The core has a pair of end surfaces facing each other in a facing direction across the gap. The core includes plural split cores joined to one another. Each pair of split cores of the plural split cores adjacent to each other have respective joining surfaces joined to each other. The respective joining surfaces of the each pair of split cores being parallel to the facing direction. This current sensor has a desired sensitivity characteristic.

A current sensor is configured to detect a current flowing through an electrical conductor. The current sensor includes a core and a coil wound around the core. The core has a hollow therein configured to allow the electrical conductor to pass through the hollow. The core substantially has a C-shape having a gap connected to the hollow. The core has a pair of end surfaces facing each other in a facing direction across the gap. The core includes plural split cores joined to one another. Each pair of split cores of the plural split cores adjacent to each other have respective joining surfaces joined to each other. The respective joining surfaces of the each pair of split cores being parallel to the facing direction. This current sensor has a desired sensitivity characteristic.

A flexible sheet-type leak sensor device according to the present invention comprises: a flexible base sheet made of a non-conductive fluorine-based synthetic resin comprising ethylene tetrafluoroethylene (ETFE); conductive lines formed on a surface of the base sheet so as to have a predetermined pattern and so as not to meet or cross each other, the conductive lines being formed by depositing on the base sheet surface a carbon black-containing, conductive fluorine-based synthetic resin comprising ethylene tetrafluoroethylene (ETFE); and a conductive material composed of pure carbon black, formed at the bottom of the conductive lines.