A protection circuit including an inrush current detector operable to detect an inrush current from a DC link is disclosed herein. The inrush current detector includes a transistor switch that is turned on in normal operation of the protection circuit. The protection circuit operates to detect when the voltage across the transistor switch exceeds a threshold voltage in response to a detected inrush current, and in response operates to turn off the transistor switch.

The present invention relates to a circuit protection device including: a device comprising a heating element configured to comprise a body and a pair of electrodes formed on the body, and a pair of lead wires connected, respectively, to the pair of electrodes; and a case having an independent accommodating space formed therein to accommodate at least the heating element, wherein the case includes at least one heat insulating layer disposed in the vicinity of the accommodating space.

A charging protection and regulation device includes a matrix of Positive Temperature Coefficient (PTC) devices having multiple legs each including one or more PTC devices, a matrix of diodes having multiple legs and multiple types of diodes having different voltage drops, and a matrix of resistors having multiple legs each including a current limiting resistor. Each PTC device is thermally coupled to an ambient environment using a different amount of thermal coupling. Respective legs of the matrix of PTC devices, matrix of diodes, and matrix of resistors are electrically coupled together, and coupled to one or more electron storage devices. During conditions of overload or circuit fault, the PTC devices act as high resistance circuit interrupters. During conditions of light loading between input and output terminals, the different voltage drops across the diodes provide voltage regulation/current regulation such that a specified charge voltage is provided to electron storage devices.

A current cut-off device for high-voltage DC current includes: between a primary point and an intermediate point, a primary diversion member and, in parallel, a primary surge protector; a secondary mechanical switch between the intermediate point and the secondary point; a main resonator whose terminal is linked to the secondary point; a main oscillation switch; a main surge protector, in parallel with a main capacitance of the main resonator; wherein the main oscillation switch includes three terminals linked respectively to the primary point, to the intermediate point and to the other terminal of the main resonator; the changeover switch can switch at least between three direct, inverting and isolated states.

An over-current protection device includes a resistor element, an outer electrode, and an encapsulation layer. The resistor element has a first insulation layer, a first electrically conductive layer, a PTC material layer, a second electrically conductive layer and a second insulation layer stacked sequentially from bottom to top. The first insulation layer has a. bottom surface and a first sidewall adjoining the bottom surface. The outer electrode has a first electrode and a second electrode disposed on the bottom surface. The first and second electrodes are electrically connected to the first conductive layer through the first and second vias, respectively. The encapsulation layer covers the first sidewall of the first insulation layer and extends to a part of the bottom surface, thereby forming a first perimeter on the bottom surface of the first insulation layer. The first and second electrodes are located inside the first perimeter.

A novel polymer positive temperature coefficient (PPTC) material, device, and method of fabrication. The PPTC device may include a PPTC body; a first electrode disposed on a first surface of the PPTC body and a second electrode disposed on a second surface of the PPTC body, opposite the first electrode. The PPTC body may include a polymer matrix; and a conductive filler, disposed in the polymer matrix. The conductive filler may include a tungsten carbide component comprising at least 30 volume percent of the PPTC body; and a carbon component, wherein a total volume fraction of the conductive filler comprises between forty volume percent and sixty five volume percent of the PPTC body.

A device for controlling a pre-charge current generated when electrically connecting a first terminal and a second terminal, according to one embodiment of the present invention, may comprise: a switch for controlling a magnitude of a current flowing between the first terminal and the second terminal; a first resistor for generating a base voltage of a first transistor in proportion to a magnitude of the pre-charge current flowing between the first terminal and the second terminal; the first transistor for limiting the magnitude of the pre-charge current when a voltage generated by the first resistor is equal to or greater than a predetermined threshold voltage; a photocoupler for receiving, in a state insulated from a first power source, an optical signal from the first power source and supplying power; a capacitor charged by the power supplied by the photocoupler; a second transistor for controlling the magnitude of the pre-charge current on the basis of a charging voltage of the capacitor; and a second resistor for controlling an operating time of the second transistor along with the capacitor.

A pPTC heating device having areas with different power densities distributed over the surface of the device. The device is constructed using a base layer composed of a pPTC material having a layer of sectioned conductive plates disposed over and under the layer of pPTC such as to control the path of the current through the device, thereby controlling resistance of the device and the power density of the device.

A network apparatus includes a hybrid data/power cable further including a power conductor and a data conductor extending between a first end and a second end thereof, the first end of the hybrid data/power cable terminating with a first connector head. The first connector head includes a fuse element coupled in series with the power conductor of the hybrid data/power cable. A remote device is coupled to the second end of the hybrid data/power cable for receiving a data signal from the data conductor of the hybrid data/power cable and a DC voltage from the power conductor of the first hybrid data/power cable. The remote device includes a current-limiting circuit coupled in series with the power conductor of the first hybrid data/power cable to produce a DC voltage at an output of the current-limiting circuit. The remote device further includes a buck/boost converter coupled to the output of the current-limiting circuit for adjusting the DC voltage. An external power supply may also be provided for the remote device.

A charging protection and regulation device includes a matrix of Positive Temperature Coefficient (PTC) devices having multiple legs each including one or more PTC devices, a matrix of diodes having multiple legs and multiple types of diodes having different voltage drops, and a matrix of resistors having multiple legs each including a current limiting resistor. Each PTC device is thermally coupled to an ambient environment using a different amount of thermal coupling. Respective legs of the matrix of PTC devices, matrix of diodes, and matrix of resistors are electrically coupled together, and coupled to one or more electron storage devices. During conditions of overload or circuit fault, the PTC devices act as high resistance circuit interrupters. During conditions of light loading between input and output terminals, the different voltage drops across the diodes provide voltage regulation/current regulation such that a specified charge voltage is provided to electron storage devices.