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  2. Equivalent impedance transforms - Wikipedia

    en.wikipedia.org/wiki/Equivalent_impedance...

    However, analysis of networks with other impedance elements proceed by the same principles. Two meshes are shown, with numbers in circles. The sum of impedances around each mesh, p, will form the diagonal of the entries of the matrix, Z pp. The impedance of branches shared by two meshes, p and q, will form the entries -Z pq.

  3. Quarter-wave impedance transformer - Wikipedia

    en.wikipedia.org/wiki/Quarter-wave_impedance...

    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 ...

  4. Impedance matching - Wikipedia

    en.wikipedia.org/wiki/Impedance_matching

    Reducing the output impedance of power pentodes (such as the EL34) in a common-cathode configuration. The impedance of the loudspeaker on the secondary coil of the transformer will be transformed to a higher impedance on the primary coil in the circuit of the power pentodes by the square of the turns ratio, which forms the impedance scaling factor.

  5. Electrical impedance - Wikipedia

    en.wikipedia.org/wiki/Electrical_impedance

    In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit. [1]Quantitatively, the impedance of a two-terminal circuit element is the ratio of the complex representation of the sinusoidal voltage between its terminals, to the complex representation of the current flowing through it. [2]

  6. Open-circuit test - Wikipedia

    en.wikipedia.org/wiki/Open-circuit_test

    Hence the iron loss is maximum at rated voltage. This maximum iron loss is measured using the wattmeter. Since the impedance of the series winding of the transformer is very small compared to that of the excitation branch, all of the input voltage is dropped across the excitation branch. Thus the wattmeter measures only the iron loss.

  7. Short-circuit test - Wikipedia

    en.wikipedia.org/wiki/Short-circuit_test

    A different form of short-circuit testing is done to assess the mechanical strength of the transformer windings, and their ability to withstand the high forces produced if an energized transformer experiences a short-circuit fault. Currents during such events can be several times the normal rated current.

  8. Y-Δ transform - Wikipedia

    en.wikipedia.org/wiki/Y-Δ_transform

    For equivalence, the impedance between any pair of terminals must be the same for both networks. The equations given here are valid for complex as well as real impedances. Complex impedance is a quantity measured in ohms which represents resistance as positive real numbers in the usual manner, and also represents reactance as positive and ...

  9. Transformer - Wikipedia

    en.wikipedia.org/wiki/Transformer

    In electrical engineering, 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.