In a protective device fuses are respectively provided in three current paths from a battery to respective loads. A microcomputer outputs, to a synthesis circuit, pulse signals having pulses in mutually-different positions. The pulse signals correspond to the fuses, respectively. The synthesis circuit synthesizes a pulse signal corresponding to a fuse, among the fuses, that has a voltage on a downstream-side end less than a threshold. The microcomputer identifies a blown fuse on the basis of a synthesized signal synthesized by the synthesis circuit.

Examples include detection of high temperature events. In some examples, a high temperature event may be detected in an electronic component by running the electronic component on a printed circuit board. A continuity sensor may detect whether a trace positioned under the electronic component has broken. A broken trace may indicate a high temperature event in the electronic component. Based on the detection of the broken trace, the electronic component is disconnected.

In accordance with one example, the electronic switch has a load current path operably coupled to a load via a wire; the electronic switch is configured to connect or disconnect a load current supply node and the load via the wire dependent on a drive signal. Further, the electronic fuse circuit includes a monitoring circuit configured to receive a current sense signal representing the load current passing through the wire and to determine a first protection signal based on the current sense signal and at least one wire parameter. The first protection signal is indicative of whether to disconnect the load current supply node from the load. Moreover, the electronic fuse circuit includes a logic circuit configured to receive at least one selection signal and to set the at least one wire parameter based on the at least one selection signal.

A voltage transient detector includes circuitry for transmitting electrical current through a light emitting diode and a fuse that is serially connected between the light emitting diode and a reference potential, such that the light emitting diode is illuminated when the fuse is not blown. The voltage transient detector also includes circuitry for transmitting a controlled amount of electrical current through the fuse in conjunction with an occurrence of a voltage transient at a voltage measurement location, where the voltage transient exceeds a set transient threshold voltage. The controlled amount of electrical current transmitted through the fuse causing the fuse to blow and the light emitting diode to turn off, thereby indicating occurrence of the voltage transient at the voltage measurement location.

A method for detection of a fuse failure of a protective fuse used to protect an associated load against overcurrent and/or against overload includes the steps of: measuring electrical current flowing through the protective fuse in a current path to the load by means of a current sensor element; determining one or more failure indicators adapted to indicate a possible failure of the protected fuse on the basis of the measured electrical current; and detecting automatically a failure of the protective fuse if the determined at least one failure indicator indicates a possible failure of the protective fuse and if the electrical current stopped to flow through the protective fuse or is below a predefined current threshold value.

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.

This power supply device includes: an AC path from an input end to an output end; a current sensor configured to detect a current flowing through the AC path; a conversion unit connected to the AC path and being capable of bidirectional power conversion; a storage battery connected to the AC path via the conversion unit; an AC switch provided between the input end and a point at which the conversion unit is connected to the AC path, the AC switch including parallel body of a relay contact and a semiconductor switch; and a control unit configured to control the conversion unit and the AC switch. When the control unit executes a current conduction mode for the first time, and when the current sensor detects an excessive current during the current conduction mode, the control unit closes only the relay contact while keeping the semiconductor switch opened.

A surge reduction filter (SRF) includes a cartridge having a cartridge housing, a first active connection point for connection to an active line of an AC power supply, and a neutral connection point for connection to a neutral line of the AC power supply. The active and neutral connection points are located to be accessible from outside the cartridge. A first fuse and a first surge protection element are electrically connected in series between the active and neutral connection points. A status circuit is connected to monitor the surge protection element and an indicator is connected to the status circuit to indicate at least a normal status and a fault status of the surge protection element. The status circuit detects a change in voltage at a point between the fuse and the protection element and creates a fault indication if a voltage change is detected due to the fuse operating.

A circuit board and a battery connection module are provided. The circuit board has an insulating substrate and a plurality of circuit traces provided thereto. At least one of the traces is provided with a fuse unit. The fuse unit has a main fuse and at least one spare fuse. The main fuse has two main trace connection end portions respectively positioned at two ends of the main fuse and connected to the trace and a main fuse section connected between the two main trace connection end portions. The spare fuse has two trace connection end portions respectively positioned at two ends of the spare fuse and a fuse section connected between the two trace connection end portions, the fuse section and the main fuse section are spaced apart from each other and arranged side by side, and at least one of the two trace connection end portions is not connected with the trace so as to form an electrical disconnection with the trace, and after the main fuse section forms an electrical disconnection, the two trace connection end portions are connected to the trace so that a current conductive path is formed by the spare fuse and the trace.

A power conversion apparatus includes a power conversion device connected to a 3-phase AC power source, a first fuse positioned on a first phase of the source between the conversion device and the source, a second fuse positioned on a second phase of the source between the conversion device and the source, a first voltage detection device which detects first voltage between a third phase and the first phase of the source on the conversion device side with respect to the first fuse, a second voltage detection device which detects second voltage between the third and second phases of the source on the conversion device side with respect to the second fuse, and a status detection device connected to the first and second voltage devices such that the status device detects status of the first and second fuses based on comparison between detection result of the first and second voltage.