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SNCF Class BB 36000
The SNCF Class BB 36000 locomotives (named ''Astride'') are a class of triple voltage 4 axle twin bogie electric locomotives built by GEC-Alsthom (later Alstom) between 1996 and 2001 for SNCF. Sixty units were built, with thirty units later converted to subclasses ''36200'', and ''36300'' - locomotives with additional safety equipment for cross border trains between France and Italy. As of 2012 there are 30 units of the original 36000 class and 30 units of the 36300 subtype. Locomotives operating in Italy have been given the Italian designation ''FS Class E436''. The subgroup 36001-36030 operates mostly on French-Belgian freight corridors. History Background and design The first 30 locomotives of Class BB 36000 were built as a result of a modification of an order for 264 of the dual voltage SNCF Class BB 26000 (Sybic); instead only 234 Sybics were built, the last 30 of the order were instead built as a triple voltage design capable of also operating under 3 kV DC with a diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alstom
Alstom SA is a French multinational rolling stock manufacturer operating worldwide in rail transport markets, active in the fields of passenger transportation, signalling, and locomotives, with products including the AGV, TGV, Eurostar, Avelia and New Pendolino high-speed trains, in addition to suburban, regional and metro trains, and Citadis trams. Alsthom (originally Als-Thom) was formed by a merger between Compagnie Française Thomson-Houston and the electric engineering division of Société Alsacienne de Constructions Mécaniques in 1928. Significant later acquisitions included the Constructions Electriques de France (1932), shipbuilder Chantiers de l'Atlantique (1976), and parts of ACEC (Belgium, late-1980s). A merger with parts of the General Electric Company (UK) formed GEC Alsthom in 1989. Throughout the 1990s, the company expanded its holdings in the rail sector, via the acquisition of German rolling stock manufacturer Linke-Hofmann-Busch and Italian rail signall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SNCF Class BB 26000
The SNCF BB 26000 locomotives are a class of dual voltage, four axle B'B' electric locomotives capable of a top speed of 200 km/h built by GEC Alsthom between 1988 and 1998 for SNCF. The locomotives are also commonly known as the ''Sybics''.From ''Synchronous Bicurrent'', referring to synchronous motor drive, and dual voltage operation (French: ''Synchrone Bicourant'') Design and development The class were built to fulfil both freight and passenger roles; the specifications included the ability to haul 16 Corail coaches at on a 0.25% gradient, and to haul a freight train at on a 0.88% gradient. The locomotives are a two cabin design with the body built out of steel, two pantographs are fitted; one for 1500 V operation, the other for 25 kV operation. A 25 kV AC supply is stepped down and rectified to 1500 V, a 1500 V supply feeds the power electronics directly. Each of the three elements of the thyristor bridge basedThe back EMF (ie electrical generator effect) of the syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductor
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil. When the current flowing through the coil changes, the time-varying magnetic field induces an electromotive force (''emf'') (voltage) in the conductor, described by Faraday's law of induction. According to Lenz's law, the induced voltage has a polarity (direction) which opposes the change in current that created it. As a result, inductors oppose any changes in current through them. An inductor is characterized by its inductance, which is the ratio of the voltage to the rate of change of current. In the International System of Units (SI), the unit of inductance is the henry (H) named for 19th century American scientist Joseph Henry. In the measurement of magnetic circuits, it is equivalent to . Inductors have values that typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chopper (electronics)
In electronics, a chopper circuit is any of numerous types of electronic switching devices and circuits used in power control and signal applications. A chopper is a device that converts fixed DC input to a variable DC output voltage directly. Essentially, a chopper is an electronic switch that is used to interrupt one signal under the control of another. In power electronics applications, since the switching element is either fully on or fully off, its losses are low and the circuit can provide high efficiency. However, the current supplied to the load is discontinuous and may require smoothing or a high switching frequency to avoid undesirable effects. In signal processing circuits, use of a chopper stabilizes a system against drift of electronic components; the original signal can be recovered after amplification or other processing by a synchronous demodulator that essentially un-does the "chopping" process. Comparison (step down chopper and step up chopper) Comparison bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverter (electrical)
A power inverter, inverter or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the opposite of rectifiers which were originally large electromechanical devices converting AC to DC. The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or circuitry. The inverter does not produce any power; the power is provided by the DC source. A power inverter can be entirely electronic or may be a combination of mechanical effects (such as a rotary apparatus) and electronic circuitry. Static inverters do not use moving parts in the conversion process. Power inverters are primarily used in electrical power applications where high currents and voltages are present; circuits that perform the same function for electronic signals, which usually have very low currents and vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DC-to-DC Converter
A DC-to-DC converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. It is a type of electric power converter. Power levels range from very low (small batteries) to very high (high-voltage power transmission). History Before the development of power semiconductors, one way to convert the voltage of a DC supply to a higher voltage, for low-power applications, was to convert it to AC by using a vibrator, then by a step-up transformer, and finally a rectifier. Where higher power was needed, a motor–generator unit was often used, in which an electric motor drove a generator that produced the desired voltage. (The motor and generator could be separate devices, or they could be combined into a single "dynamotor" unit with no external power shaft.) These relatively inefficient and expensive designs were used only when there was no alternative, as to power a car radio (which then used thermionic valves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chopper (electronics)
In electronics, a chopper circuit is any of numerous types of electronic switching devices and circuits used in power control and signal applications. A chopper is a device that converts fixed DC input to a variable DC output voltage directly. Essentially, a chopper is an electronic switch that is used to interrupt one signal under the control of another. In power electronics applications, since the switching element is either fully on or fully off, its losses are low and the circuit can provide high efficiency. However, the current supplied to the load is discontinuous and may require smoothing or a high switching frequency to avoid undesirable effects. In signal processing circuits, use of a chopper stabilizes a system against drift of electronic components; the original signal can be recovered after amplification or other processing by a synchronous demodulator that essentially un-does the "chopping" process. Comparison (step down chopper and step up chopper) Comparison bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulse-width Modulation
Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts. The average value of voltage (and current) fed to the load is controlled by turning the switch between supply and load on and off at a fast rate. The longer the switch is on compared to the off periods, the higher the total power supplied to the load. Along with maximum power point tracking (MPPT), it is one of the primary methods of reducing the output of solar panels to that which can be utilized by a battery. PWM is particularly suited for running inertial loads such as motors, which are not as easily affected by this discrete switching, because their inertia causes them to react slowly. The PWM switching frequency has to be high enough not to affect the load, which is to say that the resultant waveform perceived by the load must be as smooth as possible. The rate (or frequency) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil. Transformers are used to change AC voltage levels, such transformers being termed step-up or step-down type to increase or decrease voltage level, respectively. Transformers can also be used to provide galvanic isolation between circuits as well as to couple stages of signal-processing circuits. Since the invention of the first constant-potential transformer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montreal Convention
The Montreal Convention (formally, the Convention for the Unification of Certain Rules for International Carriage by Air) is a multilateral treaty adopted by a diplomatic meeting of ICAO member states in 1999. It amended important provisions of the Warsaw Convention's regime concerning compensation for the victims of air disasters. The Convention attempts to re-establish uniformity and predictability of rules relating to the international carriage of passengers, baggage and cargo. Whilst maintaining the core provisions which have served the international air transport community for several decades (i.e., the Warsaw regime), the treaty achieves modernization in a number of key areas. It protects passengers by introducing a two-tier liability system that eliminates the previous requirement of proving willful neglect by the air carrier to obtain more than US$75,000 in damages, which should eliminate or reduce protracted litigation. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freon
Freon ( ) is a registered trademark of the Chemours Company and generic descriptor for a number of halocarbon products. They are stable, nonflammable, low toxicity gases or liquids which have generally been used as refrigerants and as aerosol propellants. These include the chlorofluorocarbons (CFCs) that cause ozone depletion and HCFCs (such as chlorodifluoromethane). Not all refrigerants of this type are labelled as "Freon" since Freon is a brand name for the refrigerants R-12, R-13B1, R-22, R-410A, R-502, and R-503 manufactured by The Chemours Company. Freon emits a strong chemical smell similar to acetone, a nail polish remover component. History The first CFCs were synthesized by Frédéric Swarts in the 1890s. In the late 1920s, a research team was formed by Charles Franklin Kettering in General Motors to find a replacement for the dangerous refrigerants then in use, such as ammonia. The team was headed by Thomas Midgley, Jr. In 1928, they improved the synthesis of CFCs a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Compatibility
Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment. The goal of EMC is the correct operation of different equipment in a common electromagnetic environment. It is also the name given to the associated branch of electrical engineering. EMC pursues three main classes of issue. Emission is the generation of electromagnetic energy, whether deliberate or accidental, by some source and its release into the environment. EMC studies the unwanted emissions and the countermeasures which may be taken in order to reduce unwanted emissions. The second class, susceptibility, is the tendency of electrical equipment, referred to as the victim, to malfunction or break down in the presen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
