Galvanic isolation

Galvanic isolation

Galvanic isolation is the principle of isolating functional sections of electric systems so that charge-carrying particles cannot move from one section to another, i.e. there is no electric current flowing directly from one section to the next. Energy and/or information can still be exchanged between the sections by other means, however, such as by capacitance, induction, electromagnetic waves, optical, acoustic, or mechanical means.

Galvanic isolation is used in situations where two or more electric circuits must communicate, but their grounds may be at different potentials. It is an effective method of breaking ground loops by preventing unwanted current from travelling between two units sharing a ground conductor.Galvanic isolation is also used for safety considerations, preventing accidental current from reaching the ground (the building floor) through a person's body.

Overview

*Transformers couple by magnetic flux. Primary and secondary side have no electrical connection. The isolation voltage (industry standard) is measured in kilovolt.
*Optocouplers transmit information by light waves. The sender (light source) and receiver (photosensitive device) are electrically isolated.
*Autotransformers do not provide galvanic isolation.
*If two electronic systems have a common ground, they are not galvanically isolated (by definition). The common ground might not have connection to functional poles, but might become connected at an undefined point of time. For this reason Isolation transformers do not supply a "GND/earth pole".

Applications

*Optocouplers to decouple a secondary function block from a primary function block, connected to the power grid (or high voltage).
*Optocouplers to decouple one signal potential from another signal potential.
*Power sockets intended for electric razor supply must employ a residual-current device or an isolation transformer (to prevent an electric shock if the razor should be dropped into water).
*Yachts connected to improper grounded shore supply systems should employ a Galvanic Isolator to isolate from any stray currents in the marina(either from the shore mains or neighbouring yachts), without the isolator a galvanic corrosion path may be created damaging metal equipment below the waterline. Zinc anodes may help to preven this, but often prove insufficent when the yacht stays in the marina for extended periods.


Wikimedia Foundation. 2010.

Поможем написать курсовую

Look at other dictionaries:

  • Galvanic — may refer to * Galvanization * Galvanic cell * Galvanic skin response * Galvanic corrosion * Galvanic series * Galvanic bath * Galvanic anode * Galvanic isolation * Galvanic Vestibular Stimulation * Galvanism …   Wikipedia

  • Isolation transformer — An isolation transformer is a transformer, often with symmetrical windings, which is used to decouple two circuits. An isolation transformer allows an AC signal or power to be taken from one device and fed into another without electrically… …   Wikipedia

  • GI — • galvanic isolation; • gastrointestinal; • gelatin infusion [medium]; • giant interneuron; • gingival index; • globin insulin; • glomerular index; • glucose intolerance; • granuloma in guinale; • growth inhibition …   Dictionary of medical acronyms & abbreviations

  • гальваническая развязка — Мероприятие или техническое средство, применение которого направлено на исключение гальванической связи между проводящими частями. [РД 91.020.00 КТН 276 07] гальваническая развязка Схемотехническое решение, при котором исключается гальваническая… …   Справочник технического переводчика

  • Shorepower — (also known as cold ironing, shore power or shore supply, especially in the UK) is a power source from land used to power marine vessels when in a harbor. The term can also be applied to aircraft or land based vehicles (such as campers, heavy… …   Wikipedia

  • гальваническая развязка — 3.4.3 гальваническая развязка (galvanic isolation): Элемент в искробезопасном электрооборудовании, посредством которого обеспечивается передача сигнала со входа на выход без прямого электрического соединения между ними. Примечание Для… …   Словарь-справочник терминов нормативно-технической документации

  • Flyback converter — The Flyback converter is a DC to DC converter with a galvanic isolation between the input and the output(s). More precisely, the flyback converter is a buck boost converter with the inductor split to form a transformer, so that the voltage ratios …   Wikipedia

  • Solar inverter — Internal view of a solar inverter. A solar inverter or PV inverter is a critical component in a Photovoltaic system. It performs the conversion of the variable DC output of the Photovoltaic (PV) modules into a utility frequency AC current that… …   Wikipedia

  • Shielded cable — A shielded cable is an electrical cable of one or more insulated conductors enclosed by a common conductive layer. The shield may be composed of braided strands of copper (or other metal), a non braided spiral winding of copper tape, or a layer… …   Wikipedia

  • Frequency changer — A frequency changer or frequency converter is an electronic device that converts alternating current (AC) of one frequency to alternating current of another frequency. The device may also change the voltage, but if it does, that is incidental to… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”