A universal serial bus (USB) cable including a power conductor configured to transmit power between a first device and a second device, a configuration channel (CC) conductor configured to allow the first device and the second device to determine whether a connection has been established via the USB cable, and a first positive temperature coefficient (PTC) element coupled to the CC conductor and configured to mitigate current flowing through the CC conductor if a temperature of the first PTC element rises above a predefined trip temperature.

An over-current protection device is a hexahedron comprising an upper surface, a lower surface and four lateral surfaces. The over-current protection device comprises a PTC device, a first insulating layer, a first electrode layer and a second electrode layer. The PTC device comprises a first conductive layer, a second conductive layer and a PTC material layer laminated therebetween. The first conductive layer comprises a first conductive section and a second conductive section separated by at least one trench. The first insulating layer is disposed on the first conductive layer. The first electrode layer is disposed on the first insulating layer and electrically coupled to the first conductive section. The second electrode layer is disposed on the first insulating layer and electrically coupled to the second conductive section. The trench comprises a primary portion not parallel to a longitudinal direction of the first and second electrode layers.

A battery housing can include a housing body defining a cavity sized and shaped to receive a cell for a battery, and a breaker coupled with the housing body. The battery housing can comprise a first electrical conductor at a first end portion of the housing body and electrically connected to the switch, the first electrical conductor configured to electrically connect to a first battery cell terminal of the cell. The battery housing can comprise a second electrical conductor at a second end portion of the housing body, the second electrical conductor configured to electrically connect to a second battery cell terminal of the cell to define a first electrical pathway between the first electrical conductor and the second electrical conductor. The battery housing can include a bypass conductor to define a second electrical pathway between the switch and the second electrical conductor.

An electric component with a fail safe element is disclosed. In an embodiment a component includes a functional element and a fail safe element electrically interconnected therewith, wherein the fail safe element is configured to ensure a minimum resistance or a minimum conductivity of the component in the event of a failure of the functional element.

An over-current protection device includes first and second electrodes and a positive temperature coefficient (PTC) multilayered structure disposed between the first and second electrodes. The PTC multilayered structure includes a first polymer layer that is bonded to the first electrode, an intermediate layered unit that is bonded to said first polymer layer and that includes a second polymer layer, a third polymer layer that is bonded to and disposed between the intermediate layered unit and the second electrode. The first, second and third polymer layers respectively have first, second and third volume resistances, the second volume resistance being higher than the first and third volume resistances.

A cable comprises a power conductor, a data conductor and a first PTC device. The power conductor is configured to transmit electrical power between a source and a sink. The data conductor is configured to transmit data between the source and the sink. The first PTC device is coupled to the data conductor and its resistance increases drastically to decrease current flowing through the data conductor if a temperature of the first PTC device exceeds a first trip temperature. The first trip temperature is 55-80 C. The resistance of the PTC device is larger than 20k at 85 C. and larger than 80k at 100 C. A current flowing through the data conductor does not exceed 20 mA.

A DC soft turn-off module includes a switch contact and a soft turn-off circuit connected in parallel onto the switch contact. The soft turn-off circuit includes three branches connected each other in parallel. The first branch includes a thermistor and a first thyristor connected in series. The second branch comprises a capacitor and a first resistor connected in series. A second thyristor, a second resistor and a third resistor form a trigger branch for the first thyristor. The third branch includes a varistor connected in parallel onto the first branch and the second branch.

A device, according to one embodiment, includes a fuse, and a resistor electrically coupled directly to the fuse in series therewith. A hybrid device, according to another embodiment, includes a fuse, and a resistor electrically coupled directly to the fuse in series therewith in a single package. A resistance of the resistor is 1 ohm or less, and is substantially temperature insensitive.

An electrical circuit for charging a secondary battery that comprises a dc-converter and an output connector that can be connected to the positive terminal of the secondary battery for applying a charging current to the secondary battery. The dc-converter has a voltage feedback connector for sensing a feedback voltage, wherein the dc-converter is adapted to regulate the output voltage by adjusting the output current at the output connector depending on the sensed feedback voltage and a feedback-sub-circuit connected to the output connector and to the voltage feedback connector of the dc-converter.

A thermal hazard protection circuit for a transportation vehicle comprises an interruptible power circuit connected between a power source and load, and a failsafe circuit operative to permanently interrupt current flow under an overcurrent condition. The interruptible power circuit comprises a Positive Temperature Coefficient (PTC) component in series with bi-stable relay configured as a SPST switch. The failsafe circuit comprises a failsafe relay energized by current in the interruptible power circuit. An input of the failsafe relay is connected to the battery, and a normally closed (NC) output (not connected to the input so long as the failsafe relay is energized) is connected to a control input of the bi-stable relay that opens the SPST switch. In an overcurrent condition, the PTC component limits current flow, switching the failsafe relay input to its NC outputs, providing a control signal to open the SPST switch, rendering the interruptible power circuit non-conductive and isolating the load.