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In electrical engineering, dot marking convention, or alphanumeric marking convention, or both, can be used to denote the same relative instantaneous polarity of two mutually inductive components such as between transformer windings. These markings may be found on transformer cases beside terminals, winding leads, nameplates, schematic and ...
The symbol connected to the dot (usually the symbol found to the right) denotes the polarity of the center/tip, whereas the symbol connected to the broken circle denotes the polarity of the barrel/ring. When a device or adapter is described simply as having "positive polarity" or "negative polarity", this denotes the polarity of the center/tip.
For example, a transformer with a vector group of Dy1 has a delta-connected HV winding and a wye-connected LV winding. The phase angle of the LV winding lags the HV by 30 degrees. Note that the high-voltage (HV) side always comes before the low-voltage (LV) side, regardless of which is the primary winding.
A high-voltage current transformer may contain several cores, each with a secondary winding, for different purposes (such as metering circuits, control, or protection). [7] A neutral current transformer is used as earth fault protection to measure any fault current flowing through the neutral line from the wye neutral point of a transformer.
A schematic representation of long distance electric power transmission. From left to right: G=generator, U=step-up transformer, V=voltage at beginning of transmission line, Pt=power entering transmission line, I=current in wires, R=total resistance in wires, Pw=power lost in transmission line, Pe=power reaching the end of the transmission line, D=step-down transformer, C=consumers.
Illustration of the "reference directions" of the current (), voltage (), and power () variables used in the passive sign convention.If positive current is defined as flowing into the device terminal which is defined to be positive voltage, then positive power (big arrow) given by the equation = represents electric power flowing into the device, and negative power represents power flowing out.
A reference designator unambiguously identifies the location of a component within an electrical schematic or on a printed circuit board.The reference designator usually consists of one or two letters followed by a number, e.g. C3, D1, R4, U15.
A power transformer, usually used to change the utility distribution voltage to a lower voltage for use on the customer premises. Dolby A trademark for a noise reduction technique for analog sound recordings. dot convention A system for marking terminals on instrument transformers to maintain correct polarity. doubly fed electric machine