- 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 bycapacitance ,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
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Transformer s couple bymagnetic flux . Primary and secondary side have no electrical connection. The isolation voltage (industry standard ) is measured inkilovolt .
*Optocoupler s transmit information bylight waves . The sender (light source ) and receiver (photosensitive device) are electrically isolated.
*Autotransformer s do not provide galvanic isolation.
*If twoelectronic system s 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 reasonIsolation transformer s 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 forelectric razor supply must employ aresidual-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.
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