Lithium ion cells packaged in aluminium cans continue to be the highest performing cells in the market. Circuit protection for rechargeable lithium-based battery cells and packs in a critical design consideration. overcurrent and overtemperature conduction that can result from accidental shorting or abusive/runaway charging can raise temperature high enough to damage components and cause substantial damage. This paper presents the use of PPTC devices for short-circuit and overcharge of battery packs. Polymeric positive temperature coefficient [ ....etc

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The Digital Transmission Content Protection (DTCP) defines a cryptographic protocol for protecting audio /video entertainment content from illegal copying, intercepting and tampering as it traverses high performance digital buses, such as the IEEE 1394 standard. DTCP ensures that the copy protection mechanism is built into Digital Audio/Video devices themselves (in addition to Traditional Encryption). This seminar will outline the basic principles of cryptography; and tells us about the cryptographic functions used in it. It will briefly look a ....etc

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Lithium ion cells packaged in aluminium cans continue to be the highest performing cells in the market. Circuit protection for rechargeable lithium-based battery cells and packs in a critical design consideration.

overcurrent and overtemperature conduction that can result from accidental shorting or abusive/runaway charging can raise temperature high enough to damage components and cause substantial damage.

This paper presents the use of PPTC devices for short-circuit ....etc

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Overvoltage protection concept for DC railway systems



ABSTRACT

Overvoltages in electrical networks result from the effects of lightning strokes and switching actions and cannot be avoided. Furthermore, the power supply of electrical railways is endangered by direct or nearby lightning. A new device, combining protection against overvoltages and touch voltages and protection of people is introduced. Protection concepts for DC railway systems are introduced, cons ....etc

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This article describes the Voltage swell and overvoltage compensation problems in a diode-bridge rectifier supported transformerless-coupled
dynamic voltage restorer (DVR). applying conventional in-phase or phase-invariant boosting method in case of condition of swell or overvoltage, may cause a a rapid rise in dc-link voltage which may ultimately lead to the damage of the storage capacitors and switching devices, and increase the switching loss. The minimum energy injection scheme is unable to solve these problems. Here, a novel unidirectio ....etc

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This is a new technique for the protection of transmission systems by using the global positioning system (GPS) and fault generated transients. In this scheme the relay contains a fault transient detection system together with a communication unit, which is connected to the power line through the high voltage coupling capacitors of the CVT.

Relays are installed at each bus bar in a transmission network. These detect the fault generated high frequency voltage transient signals and record the time instant corresponding to when the initial ....etc

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Introduction

A new simple, effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using long flashover arresters (LFA). A new long flashover arrester model has been developed. It is designated as LFA-M. It offers great number of technical and economical advantages.

The important feature of this modular long flashover arrester (LFA-M) is that it can be applied for lightning protection of overhead distribution line against both induced overvoltages and direct lightning strokes. The induce ....etc

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The recent growth of power circuit capacities has caused fault currents to increase. Since the protection of power systems from the fault currents is very important, it is needed to develop a fault current limiter.

A fault current limiter is required to assure (1) rapid reaction to fault currents, (2) how impedance in normal operation and (3) large impedance during fault conditions. A super conducting fault current limiter (SCFCL) can meet these requirements superconductors, because of their sharp transition from zero resistance at normal cu ....etc

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Voltage surges are unpredictable, momentary increases in voltage. Typically, lightning, inductive switching, or power switching cause surges, which can damage the insulation in building wiring, electrical appliances, or electronic equipment.

Power surges, which can create havoc with today's highly sensitive electrical and electronic equipment, are an unavoidable fact of life. Power surges, both voltage and current, are occurring continually in today?s power systems.

Whether they occur naturally, such as from lightning and static electri ....etc

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please send me matlab program for overvoltage and undervoltage protection of electrical devices ....etc

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