Phase inversion

Phase inversion

A phase inversion is the introduction of a phase difference of 180° into a waveform. As such, it is more properly called a "polarity" inversion, as phase can differ relative to frequency but polarity is absolute.

For example, in a push-pull power amplifier using vacuum tubes, the signal is most often "split" by a phase splitter (aka phase inverter) stage which produces two signals, one "in phase", and the other "out of phase", that is, phase inverted. These two signals then drive the two halves of the first push-pull stage, which may be either the output stage (in which case the phase splitter will be in between the driver stage if there is one and the output stage) or the driver stage. The other common arrangements for driving a push-pull stage are by using an isolation transformer to produce the split signals, or by using the in-phase half of the first push-pull stage to drive the other half. A common circuit using this last technique is the long-tailed pair, often seen in television sets and oscilloscopes.

In solid state electronics all of these techniques can be used, and phase inversion can also be produced by the use of NPN/PNP complementary circuitry, which has no corresponding technique in vacuum tube designs.

Phase inversion may occur with a random or periodic, symmetrical or non-symmetrical waveform, although it is usually produced by the inversion of a symmetrical periodic signal, resulting in a change in sign. A symmetrical periodic signal represented by "f" ("t" ) = "A" ej"ωt", after phase inversion, becomes "f" 1("t" ) = Aej(ω"t" +π), where "t" is time, "A" is the magnitude of the vector, ω is angular frequency (ω = 2π"f" ), where "f" is the frequency and π ≈3.1416 and e ≈ 2.7183. The algebraic sum of "f" ("t" ) and "f" 1("t" ) will always be zero.

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• phase inversion — fazės apgrąža statusas T sritis automatika atitikmenys: angl. phase inversion; phase reversal vok. Phasenumkehr, f rus. инверсия фазы, f; опрокидывание фазы, n pranc. inversion de phase, f; renversement de phase, m …   Automatikos terminų žodynas

• phase inversion — fazės apgrąža statusas T sritis fizika atitikmenys: angl. phase inversion; phase reversal vok. Phasensprung, m; Phasenumkehr, f; Phasenumkehrung, f rus. изменение фазы на противоположную, n; инверсия фазы, f pranc. inversion de phase, f;… …   Fizikos terminų žodynas

• phase inversion — fazių inversija statusas T sritis chemija apibrėžtis Emulsijos dispersinės fazės virtimas dispersine terpe ir atvirkščiai. atitikmenys: angl. phase inversion rus. обращение фаз …   Chemijos terminų aiškinamasis žodynas

• Phase inversion — A&V The condition whereby the output of a circuit produces a wave of the same shape and frequency but 180 degrees out of phase with the input …   Audio and video glossary

• inversion de phase — fazės apgrąža statusas T sritis automatika atitikmenys: angl. phase inversion; phase reversal vok. Phasenumkehr, f rus. инверсия фазы, f; опрокидывание фазы, n pranc. inversion de phase, f; renversement de phase, m …   Automatikos terminų žodynas

• inversion de phase — fazės apgrąža statusas T sritis fizika atitikmenys: angl. phase inversion; phase reversal vok. Phasensprung, m; Phasenumkehr, f; Phasenumkehrung, f rus. изменение фазы на противоположную, n; инверсия фазы, f pranc. inversion de phase, f;… …   Fizikos terminų žodynas

• phase reversal — fazės apgrąža statusas T sritis automatika atitikmenys: angl. phase inversion; phase reversal vok. Phasenumkehr, f rus. инверсия фазы, f; опрокидывание фазы, n pranc. inversion de phase, f; renversement de phase, m …   Automatikos terminų žodynas

• phase reversal — fazės apgrąža statusas T sritis fizika atitikmenys: angl. phase inversion; phase reversal vok. Phasensprung, m; Phasenumkehr, f; Phasenumkehrung, f rus. изменение фазы на противоположную, n; инверсия фазы, f pranc. inversion de phase, f;… …   Fizikos terminų žodynas

• phase inverter — noun an electronic circuit which changes the phase of a signal by 180°; used in the input stage of a push pull amplifier See Also: phase inversion …   Wiktionary

• inversion — [ ɛ̃vɛrsjɔ̃ ] n. f. • 1529; lat. inversio, de invertere « retourner » I ♦ A ♦ Sens spéciaux 1 ♦ Déplacement (d un mot ou d un groupe de mots) par rapport à l ordre normal ou habituel de la construction. Inversion du sujet dans l interrogation (ex …   Encyclopédie Universelle