In one embodiment, an apparatus for redundant control of active fuses for battery pack safety is provided, comprising a battery; an electrical load coupled to the battery via a fuse capable of being activated by an electrical signal; a sensor configured to sense a short circuit condition at the electrical load and output an analog sensor signal; an analog-to-digital converter configured to sample the analog sensor signal and output a digital sensor signal; a microcontroller configured to detect the short circuit condition at the electrical load based on the digital sensor signal, and, during normal operation, to output a first electrical signal to activate the fuse after detecting the short circuit condition at the electrical load; and an analog circuit configured to operate independently of the microcontroller to receive the analog sensor signal and output a second electrical signal to activate the fuse after receiving the analog sensor signal.

A surge protective device (SPD) assembly includes a base and an SPD module configured to be mounted on the base. The SPD module includes an SPD module PCB, an SPD module circuit, and a thermal disconnector mechanism. The SPD module circuit is at least partly embodied in the SPD module PCB and includes an overvoltage protection component mounted on the SPD module PCB. The thermal disconnector mechanism is mounted on the SPD module PCB in a ready configuration. The thermal disconnector mechanism is operative to transition from the ready configuration to an actuated configuration responsive to sufficient overheating of the overvoltage protection component. When the thermal disconnector mechanism is positioned in the ready configuration, the SPD circuit forms a first current path through the overvoltage protection component. When the thermal disconnector mechanism is positioned in the actuated configuration, the thermal disconnector mechanism forms an alternate second current path that bypasses the overvoltage protection component.

A device includes a relative temperature detector configured to determine a temperature difference between a device temperature sensed near a switch device and an ambient temperature sensed outside the switch device. The relative temperature detector is configured to generate a relative temperature output signal based on comparing the temperature difference to a relative temperature threshold. A power detector is configured to generate a power level signal based on comparing an indication of switch power of the switch device to a power threshold. The power level signal specifies whether the indication of switch power is above or below the power threshold. A thermal capacity control is configured to disable the switch device based on the power level signal specifying that the indication of switch power is above the power threshold and based on the relative temperature output signal indicating the temperature difference is above the relative temperature threshold.

A current detecting device includes a sense resistor through which a sense current corresponding to a consumption current supplied to a load flows, and an A/D converter configured to perform A/D conversion on a voltage drop generated by the sense current flowing through the sense resistor to detect the consumption current. A resistance value of the sense resistor is variably provided.

Provided is a protection circuit capable of reliably preventing an overcurrent or a sneak current after cutoff to improve safety, implementing cost reduction with a device configuration simpler than conventional device configurations, and further reducing a failure rate of a device. In a protection circuit, after one of two fuse elements provided in each of a plurality of protection elements is blown due to an overcurrent flowing along a current-carrying path, a heater provided in at least one of the plurality of protection elements generates heat due to a sneak current flowing via the plurality of protection elements on the current-carrying path which is remained and the current-carrying path which is remained is cut off due to destruction of the heater.

A surge protection device with a high breaking capacity includes a housing with at least two lead-out electrodes, and a voltage limiting device and a thermal tripping mechanism that are installed in the housing. The voltage limiting device includes a voltage limiter, a first electrode and a second electrode that are positioned and installed in an insulating cover. The thermal tripping mechanism includes a fixed assembly, a movable assembly and a thermal trigger device. The fixed assembly and the movable assembly form a plurality of displacement switches arranged in series. The thermal trigger device is disposed in linkage with the movable assembly and includes a metal trigger sheet, a fusible alloy and an energy storage member. One end of the metal trigger sheet is fixed on the movable assembly, and the other end of the metal trigger sheet is fixed on the second electrode through welding by the fusible alloy.

A control and protection circuit of a heater, a towel heating barrel and a control method thereof are provided in this disclosure. The control and protection circuit of the heater includes a power module, a power supply module, a control module, a temperature detection module and a heating module. The power module, the power supply module and the heating module are connected in series to supply power to the heating module, the control module is in signal connection with the power supply module to control on and off of the power supply module, and the temperature detection module in signal connection with the control module. The power supply module includes a high-temperature protection switch, a fuse and a relay. The control and protection circuit of the whole heater has three levels of protection, which can not only effectively provide high-temperature protection, but also ensure service life of the heater.

In one aspect, a modular static transfer switch is provided. The module static transfer switch includes an output configured to couple to a load, a first input configured to couple to a first power source, and a second input configured to couple to a second power source. The modular static transfer switch further includes a plurality of sold-state switch modules each comprising at least one solid-state switch. A first plurality of the solid-state switch modules are coupled in parallel between the first input and the output, each configured to selectively couple the first power source to the output using the at least one solid-state switch. A second plurality of the solid-state switch modules are coupled in parallel between the second input and the output, each configured to selectively couple the second power source to the output using the at least one solid-state switch.

A resettable electronic fuse for a high-power device such as a power tool, a battery pack for the power tool, or a battery pack charger. The resettable electronic fuse is connected in a current path of the device and is operable or configured to selectively interrupt current through the resettable electronic fuse based on a detected condition of the device (e.g., a detected fault condition of the device). The resettable electronic fuse is also configured to be reset after a detected fault condition has ended. In some embodiments, the resettable electronic fuse is configured to reset itself. In other embodiments, the resettable electronic fuse is configured to receive a signal (e.g., from a device controller) to reset.

An electrochemical energy storage module and a vehicle having an energy storage module of this type. At least one energy storage cell and at least one bridging device are electrically connected in parallel. The bridging device has a first current conductor having at least one bridging point, which has a bridging point cross-section, and a second current conductor, which is spaced apart from the first current conductor by a gap. The bridging device also has a bridging switch for establishing a first partial electrical connection between the first current conductor and the second current conductor and has a bridging material arranged in the region of the bridging point.