Electrical current sensing and monitoring methods include connecting a compensation circuit across a conductor having a non-linear resistance such as a fuse element. The compensation circuit injects a current or voltage to the conductor that allows the resistance of the conductor to be determined. The current flowing in the conductor can be calculated based on a sensed voltage across the conductor once the resistance of the conductor has been determined.

Embodiments of the present disclosure provide industrial control apparatus and monitoring methods for industrial control apparatus. The industrial control apparatus comprises: at least one input or output module, each input or output module comprising a fuse adapted to be coupled between a power supply and a user load, and a detection assembly coupled to the fuse and configured to send a detection signal after monitoring that the fuse is blown; and a processing device communicatively coupled to the detection assembly of each input or output module and configured to output information that the input or output module associated with the detection signal is blown. By the aspects of the present disclosure, it is advantageous for an operator to timely obtain information that the fuse is blown and to improve the efficiency of locating and replacing the fuse.

A device includes a light source configured to emit light as an indication that an electrical protection device has operated. The electrical protection device is configured to operate in response to a fault condition detected on an energized conductor to which the electrical protection device is electrically coupled. The device further includes an optical device coupled to the light source and configured to channel the emitted light from a first end portion of the optical device to a second end portion of the optical device, and a photosensor optically coupled to the second end portion of the optical device and configured to detect the emitted light.

An in-vehicle device of the present invention includes a fuse and an upstream capacitor having one end connected to a connection node upstream of the fuse in a current path of current that flows through the fuse. One end of a downstream capacitor is connected to a connection node downstream of the fuse in the current path. A determiner determines whether or not the fuse is blown based on an upstream voltage that passed through the upstream capacitor and a downstream voltage that passed through the downstream capacitor.

The present invention relates to a method for checking the switch-off capability of an electronic fuse which is arranged between a voltage source and a consumer. The method includes monitoring a voltage at the consumer, switching the electronic fuse to a non-conductive state, and checking whether the voltage at the consumer drops to a threshold voltage within a set time. The present invention also relates to a system for checking the switch-off capability of an electronic fuse. The system includes a voltage source, a consumer, an electronic fuse between the voltage source and the consumer, a voltage measuring device to measure the voltage at the consumer, and a checking unit. The checking unit monitors the voltage at the consumer via the voltage measuring device, switches the electronic fuse to a non-conductive state, and checks whether the voltage at the consumer drops to a threshold voltage within a set time.

A plurality of fuses (F1, F2, . . . , and Fn) are respectively disposed on current paths for a plurality of currents branched from one end of a DC power source (10). In a blown fuse detection apparatus (11), ends on one side of a plurality of capacitors (C1, C2, . . . , Cn) are respectively connected to the ends on the downstream side of the plurality of fuses (F1, F2, . . . , and Fn). A plurality of currents that have flowed through the capacitors (C1, C2, . . . , Cn) are input to a circuit switch (30) and a circuit resistor (31). A microcomputer (37) instructs that the circuit switch (30) be switched on, obtains a detected value of a resistance voltage, and detects, based on the obtained detected value, whether or not there is a blown fuse among the fuses (F1, F2, . . . , and Fn).

An ECU (on-board device) includes a fuse F1 and a blown fuse detection circuit. The blown fuse detection circuit monitors a fuse voltage between two connection nodes respectively located upstream and downstream of the fuse in a current path of a current flowing from a positive electrode of a DC power supply through the fuse. The blown fuse detection circuit outputs a voltage lower than a reference voltage if the fuse voltage is lower than a voltage threshold value. The blown fuse detection circuit outputs a voltage higher than or equal to the reference voltage if the fuse voltage is higher than or equal to the voltage threshold value.