A surge protection apparatus may include an input terminal; an output terminal, the output terminal electrically coupled to the input terminal; a ground terminal, the ground terminal electrically coupled to the input terminal and output terminal: a positive temperature coefficient (PTC) fuse, the PTC fuse connected in electrical series between the input terminal and output terminal; a crowbar device, the crowbar device electrically connected to the ground terminal and output terminal, wherein the crowbar device is in electrical series with the PTC fuse between the input terminal and ground terminal; and a central frame portion, the central frame portion electrically coupled to the input terminal, output terminal and ground terminal, wherein the crowbar device is disposed on a first side of the central frame portion and the PTC fuse is disposed on a second side of the central frame portion, opposite the first side.

A motor vehicle multi-voltage battery device, includes: a first electrical output terminal and an electrical ground terminal providing a first rated voltage; a second electrical output terminal and the electrical ground terminal providing a second rated voltage; a first series circuit having a first battery cell group and a first controllable switch between the first electrical output terminal and electrical ground terminal; a protective resistor parallel to the first switch. The first switch configured to bridge the protective resistor in a closed state; a second battery cell group between the second electrical output terminal and the first electrical output terminal connected switchably in series with the first battery cell group; and a battery management assembly configured to switch the first switch into an open state to protect the first battery cell group.

A composite circuit protection device includes first and second positive temperature coefficient (PTC) components, a voltage-dependent resistor, and first, second and third conductive leads. The first PTC component includes a first PTC layer, and first and second electrode layers respectively disposed on two opposite surfaces of the first PTC layer. The second PTC component includes a second PTC layer, and third and fourth electrode layers respectively disposed on the two opposite surfaces of the second PTC layer. The voltage-dependent resistor is connected to the second and third electrode layers. The first, second and third conductive leads are bonded to the first electrode layer, the voltage-dependent resistor, and the fourth electrode layer, respectively.

A over-current protection device includes a positive temperature coefficient (PTC) polymeric element having two opposite surfaces, two electrodes respectively connected to the surfaces of the PTC polymeric element, and a power-free trip indicator disposed on at least one of the electrodes for sensing temperature of the over-current protection device.

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 20 kΩ at 85° C. and larger than 80 kΩ at 100° C. A current flowing through the data conductor does not exceed 20 mA.

A circuit arrangement for protection against an undue overheating of a charging control, discharging control and/or a secondary battery is disclosed, the circuit arrangement comprising the secondary battery, the charging and/or discharging control for charging and/or discharging the secondary battery, a connector for connecting the charging and discharging control to an external power supply, at least one current limiting electronic component arranged in electrical connection to the charging and/or discharging control and optionally, a switchable load.

A power system includes a control circuit, a power conversion circuit, a current detection circuit and a overheat detection circuit. The control circuit is for generating one or more pulse signal. The power conversion circuit is electrically coupled to the control circuit, for generating an output current according to the pulse signal. The current detection circuit is electrically coupled to the power conversion circuit, for generating a sensing current according to the output current. The overheat detection circuit is electrically coupled to the current detection circuit and the control circuit, for generating the correction current according to a temperature of the power conversion circuit. The control circuit adjusts a duty ratio of the pulse signal according to a correction sensing current to adjust the output current, and the correction sensing current is a sum of the value of the sensing current and the correction current.

A system includes a module having at least one input/output (I/O) channel. The system also includes a terminal block having terminals configured to provide electrical connections for the at least one I/O channel. The system further includes a barrier assembly having one or more intrinsic safety (IS) barriers. Each IS barrier is configured to receive at least one data or power signal, limit an amount of energy in the at least one data or power signal, and output the at least one energy-limited data or power signal. Each IS barrier includes at least one limiter circuit configured to limit the amount of energy in the at least one data or power signal. Each IS barrier is configured to be mounted on the terminal block. Each IS barrier could be configured to provide galvanic isolation between multiple devices or systems coupled to the IS barrier. Each limiter circuit could include a current limiter.

An over-current protection device comprises first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer comprises a polymer, an electrically conductive filler and a metal compound filler. The PTC material layer comprises the polymer of 50-70% by volume, and the electrically conductive filler and the metal compound filler are distributed in the polymer. The metal compound filler has a particle size D50 of 2-15 m and 5-20% by volume and is selected from the group consisting of aluminum nitride, aluminum hydroxide, aluminum oxide, titanium oxide and zirconium oxide. The over-current protection device has a resistivity of 0.7-1.2 .Math.cm.

A circuit protection device including a primary fuse, and a positive temperature coefficient (PTC) device and a secondary fuse electrically connected in series with one another and in parallel with the primary fuse, the secondary fuse formed of a quantity of solder disposed on a dielectric surface, wherein the dielectric surface exhibits a de-wetting characteristic relative to the solder such that, when the solder is melted, the solder draws away from the dielectric surface to create a galvanic opening.