Search results
Results from the WOW.Com Content Network
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.
Diagram of center-tapped transformer. In electronics, a center tap (CT) is a contact made to a point halfway along a winding of a transformer or inductor, or along the element of a resistor or a potentiometer. Taps are sometimes used on inductors for the coupling of signals, and may not necessarily be at the half-way point, but rather, closer ...
where A is the cross-sectional area of the coil and N is the number of turns. The Rogowski coil has a low sensitivity due to the absence of a high permeability magnetic core that the current transformer can take advantage of. However, this can be compensated for by adding more turns on the Rogowski coil or using an integrator with a higher gain k.
A current clamp uses a current transformer with a split core that can be easily wrapped around a conductor in a circuit. This is a common method used in portable current measuring instruments but permanent installations use more economical types of current transformer.
Assuming the desired voltage is the same on the two and three phase sides, the Scott-T transformer connection (shown right) consists of a centre-tapped 1:1 ratio main transformer, T1, and a √ 3 /2(≈86.6%) ratio teaser transformer, T2. The centre-tapped side of T1 is connected between two of the phases on the three-phase side.
A "transformer bank", widely used in North America: three single-phase transformers connected to make a 3-phase transformer. The low-voltage secondary windings are attached to three or four terminals on the transformer's side. In North American residences and small businesses, the secondary is often the split-phase 120/240-volt system. The 240 ...
The quarter wave transformer is an alternative to a stub; but, whereas a stub is terminated in a short (or open) circuit and the length is chosen so as to produce the required impedance transformation, the λ/4 transformer is in series with the load and its length and characteristic impedance are designed to produce the required impedance ...
Transformer winding primary (usually high-voltage) connecting wires are of many types. They may be labeled as H 1, H 2 (sometimes H 0 if it is internally designed to be grounded) and X 1, X2 and sometimes an X 3 tap may be present. Sometimes a second isolated winding (Y 1, Y 2, Y 3) (and third (Z 1, Z 2, Z 3) may also be available on the same ...