Transformer definition

Background [ ] Before transformers, most state-of-the-art NLP systems relied on gated RNNs, such as The terms "query", "key", "value" are borrowed from Previous work [ ] In 1992, In a fast weight controller, a Sequential processing [ ] Gated RNNs process n . Theoretically, the information from one token can propagate arbitrarily far down the sequence, if at every point the state continues to encode contextual information about the token. In practice this mechanism is flawed: the Self-attention [ ] These problems were addressed by attention mechanisms. Attention mechanisms let a model draw from the state at any preceding point along the sequence. The attention layer can access all previous states and weigh them according to a learned measure of relevance, providing relevant information about far-away tokens. A clear example of the value of attention is in last English word. Theoretically, this vector can encode information about the whole English sentence, giving the model all the necessary knowledge. In practice, this information is often poorly preserved by the LSTM. An attention mechanism can be added to address this problem: the decoder is given access to the state vectors of every English input word, not just the last, and can learn attention weights that dictate how much to attend to each English input state vector. When added to RNNs, attention mechanisms increase performance. In 2016, a new type of highly parallelizable decomposable attention was successfully combi...

A AA An Ansi (American National Standard Institute) cooling class designation indicating open, natural-draft ventilated transformer construction, usually for dry-type transformers. Ambient Temperature The temperature of the surrounding atmosphere into which the heat of the transformer is dissipated. Ampere unit of current flow. ANSI (American National Standards Institute) An organization that provides written standards on transformer [ 6OOv and below (ANSI C89.1), 601~ and above (ANSI C57.12)]. Autotransformer A transformer in which part of the winding is common to both the primary and the secondary circuits. B BIL peak) value that the insulation is required to withstand without failure. Bushing An electrical insulator ( porcelain, epoxy, etc.) that is used to control the high voltage stresses that occur when an energized cable must pass through a grounded barrier. Buck transformer Step down the Voltage from Primary Winding to Secondary Winding i.e. 460V to 230V. Boost transformer Step up the Voltage from Primary Winding to Secondary Winding i.e. 230V to 460V. C Cast-coil Transformer A transformer with high-voltage coils cast in an epoxy resin. Usually used with 5 to 15 kV transformers. Continuous Rating Gaines the constant load that a transformer can carry at rated primary voltage and frequency without exceeding the specified temperature rise. Copper Losses See Load Losses. Core-Form Construction A type of core construction where the winding materials completely enclose t...

Definition – The potential transformer may be defined as an instrument transformer used for the transformation of voltage from a higher value to the lower value. This transformer step down the voltage to a safe limit value which can be easily measured by the ordinary low voltage instrument like a voltmeter, wattmeter and watt-hour meters, etc. Construction of Potential Transformer The potential transformer is made with high-quality core operating at low flux density so that the magnetising current is small. The terminal of the transformer should be designed so that the variation of the voltage ratio with load is minimum and the phase shift between the input and output voltage is also minimum. The primary winding has a large number of turns, and the secondary winding has a much small number of turns. For reducing the leakage reactance, the co-axial winding is used in the potential transformer. The insulation cost is also reduced by dividing the primary winding into the sections which reduced the insulation between the layers. Connection of Potential Transformer The potential transformer is connected in parallel with the circuit. The primary windings of the potential transformer are directly connected to the power circuit whose voltage is to be measured. The secondary terminals of the potential transformer are connected to the measuring instrument like the voltmeter, wattmeter, etc.The secondary windings of the potential transformer are magnetically coupled through the magne...