In order to achieve a universal, flexible and highly integrated operating device for driving various lamps, ensuring the protection of the entire operating device and of the appliances connected thereto by means of staggered protective measures at both the input and the output, starting from the preamble of claim 1, a first branch for connecting a lamp to a first of the interface circuits (SS1) and a second branch for connecting at least one communication module to a second of the interface circuits (SS2) are connected to the coarse protection circuit (G) which short-circuits an overvoltage of the mains voltage occurring at the input of the operating device. In the first branch, a line filter (NF) is connected to the coarse protection circuit (G) and a clamp circuit (K) consisting of the fine protection circuit (F) and of a first energy absorber (E1) is connected to the line filter (NF). When the residual pulse voltage is too high, the fine protection circuit (F) activates the first energy absorber (E1), the overvoltage pulse is short-circuited and the short-circuit is deactivated again when the mains voltage reaches the next zero crossing. A second energy absorber (E2) which, when it is switched on, limits the current with the aid of a temperature-dependent resistor (NTC), is connected to the first energy absorber (E1). Moreover, the first interface circuit (SS1) comprises a protection circuit (ÜS) against overvoltage and overcurrent, and an intermediate protection circuit (M) consisting of a transmitter (Ü) and of a first fine protection circuit (F1) is connected to the coarse protection circuit (G) in the second branch. A filter (FK) for separating communication signals fed in parallel into the power supply grid is connected to the first fine protection circuit (F) and a second fine protection circuit (F2) is connected to this filter (FK). In order to protect the second interface circuit (SS2) of the operating device from overvoltage and overcurrent coming from the communication module and acting upon the operating device, the second interface circuit (SS2) comprises a protection circuit (ÜS) against overvoltage and overcurrent. The invention is used in the field of protection systems against overvoltage.

A system for protection from fires and electrical shock of components used in construction of electrical systems is disclosed using a sensing degree of characteristic before an arc fault, with the purpose to detect, annunciate, and remove the hazard before an electrical arc occurs.

A power cord includes a plug and a load connection portion connected to a load. The plug contains a plurality of plug pins which are respectively inserted in plug pin insertion holes of a power socket and connected to the power socket and a plurality of PTC thermistors, at least one of which is provided for each of the plug pins to detect a temperature of the corresponding plug pin. The PTC thermistors form one series circuit, and the power cord includes a shut-off device which turns off power supply to the load connection portion from the plug pins when a resistance value of the series circuit is equal to or higher than a predetermined value.

In a power distribution device, a current detection circuit detects a current value of a current flowing through a wire. When a switch is on, a microcomputer determines whether or not a predetermined condition is satisfied, based on the current value detected by the current detection circuit. If it is determined by the microcomputer that the predetermined condition is satisfied, a drive circuit turns off the switch.

Circuits for providing overcurrent protection are disclosed herein. The circuits feature depletion mode MOSFETs connected to resistive elements, preferably, Positive Temperature Coefficient (PTC) devices, configured in such a way so that the voltage across the PTC device is the same as the gate-to-source voltage of the MOSFET. The circuit may further be configured using a TVS diode, for clamping the drain-to-source voltage of the MOSFET during the overcurrent events. Heat transfer between the MOSFET and the PTC device facilitates overcurrent protection. A two-terminal device including a depletion mode MOSFET, a PTC device, and a TVS diode may provide overcurrent protection to other circuits. A bidirectional circuit c including two MOSFETS disposed on either side of a PTC is also contemplated for AC voltage overcurrent protection.

A system includes a vehicle including a motive electrical power path; a power distribution unit including: a current protection circuit disposed in the motive electrical power path, the current protection circuit including a fuse and a contactor in a series arrangement with the fuse; a high voltage power input coupling including a first electrical interface for a high voltage power source; and a high voltage power output coupling including a second electrical interface for a motive power load, where the current protection circuit electrically couples the high voltage power input coupling to the high voltage power output coupling.

Circuits for providing overcurrent protection are disclosed herein. The circuits feature depletion mode MOSFETs connected to resistive elements, preferably, Positive Temperature Coefficient (PTC) devices, configured in such a way so that the voltage across the PTC device is the same as the gate-to-source voltage of the MOSFET. The circuit may further be configured using a TVS diode, for clamping the drain-to-source voltage of the MOSFET during the overcurrent events. Heat transfer between the MOSFET and the PTC device facilitates overcurrent protection. A two-terminal device including a depletion mode MOSFET, a PTC device, and a TVS diode may provide overcurrent protection to other circuits. A bidirectional circuit c including two MOSFETS disposed on either side of a PTC is also contemplated for AC voltage overcurrent protection.

To provide a protecting device and a battery pack using the same, which are less likely to cause a spark even when a high voltage is applied and can safely and quickly interrupt the current path. A protecting device includes: an insulating substrate 2; a fuse element 3; a heat-generator 4 which generates heat to blow the fuse element 3; a heat-generator feeding electrode 5 which serves as a power-feeding terminal to the heat-generator 4; an insulating layer 6 which covers the heat-generator 4; and a heat-generator lead-out electrode 7 which is formed along the heat-generator 4 on the insulating layer 6 and holds the melted conductor 3a of the fuse element 3, wherein, when the heat-generator 4 is energized, the heat-generator feeding electrode 5 side thereof works as a high potential portion and the heat-generator lead-out electrode 7 side thereof works as a low potential portion, and in the heat-generator lead-out electrode 7, an overlapping area in which a distal end portion 7a extending in the high potential portion side of the heat-generator 4 overlaps the heat-generator 4 is smaller than an overlapping area in which a proximal end portion 7b extending in the low potential portion side of heat-generator 4 overlaps the heat-generator 4.

The present invention relates to a protection apparatus (100) for protecting an electrical circuit. The protection apparatus comprises a thermal protection device (10) for interrupting the electrical circuit at a specific temperature and also an insertion slot (20) for receiving a fuse (21) for interrupting the electrical circuit at a specific current intensity in the electrical circuit. The thermal protection device (10) and the insertion slot (20) are connected in series in the electrical circuit (40), wherein the insertion slot and the thermal protection device are arranged adjacently.

Devices having one primary transistor, or a plurality of primary transistors in parallel, protect electrical circuits from overcurrent conditions. Optionally, the devices have only two terminals and require no auxiliary power to operate. In those devices, the voltage drop across the device provides the electrical energy to power the device. A third or fourth terminal can appear in further devices, allowing additional overcurrent and overvoltage monitoring opportunities. Autocatalytic voltage conversion allows certain devices to rapidly limit or block nascent overcurrents.