Vocabulary Word
Word: galvanic
Definition: of the production of electricity by the action of an acid on a metal; having the effect of an electric shock; Ex. galvanic cell; galvanic effect; CF. Luigi Galvani
Definition: of the production of electricity by the action of an acid on a metal; having the effect of an electric shock; Ex. galvanic cell; galvanic effect; CF. Luigi Galvani
Sentences Containing 'galvanic'
Washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminium surfaces.
The values are most often tabulated at 25 °C. The basis for an electrochemical cell such as the galvanic cell is always a redox reaction which can be broken down into two half-reactions: oxidation at anode (loss of electron) and reduction at cathode (gain of electron).
The galvanic cell potential results from a "pair" of electrodes.
Thus, only one empirical value is available in a pair of electrodes and it is not possible to determine the value for each electrode in the pair using the empirically obtained galvanic cell potential. A reference electrode, standard hydrogen electrode (SHE), for which the potential is "defined" or agreed upon by convention, needed to be established.
In this case SHE is set to 0.00 V and any electrode, for which the electrode potential is not yet known, can be paired with SHE—to form a galvanic cell—and the galvanic cell potential gives the unknown electrode's potential. Using this process, any electrode with an unknown potential can be paired with either the SHE or another electrode for which the potential has already been derived and that unknown value can be established.
In a galvanic cell, where a spontaneous redox reaction drives the cell to produce an electric potential, Gibbs free energy Δ"G"° must be negative, in accordance with the following equation:
where "n" is number of moles of electrons per mole of products and "F" is the Faraday constant, ~96485 C/mol.
Inputs can use an opto-coupler for galvanic isolation (For more details see [http://www.posital.sg/sg/products/POSITAL/AbsoluteEncoders_Context/AbsoluteEncoders_Context_Technology_SSI_AppNote.pdf]) that can be driven by RS-422/485 levels.
However, to avoid ground loops and electrically isolate the slave, complete galvanic isolation by opto-couplers is needed.