Usuari:Jaumellecha/proves3: diferència entre les revisions

 

Prior to use, the chain was soaked in vinegar so that the electrolyte was absorbed into the wooden dowels. The wood of which the dowels were made was chosen to be a very porous type so that the amount of electrolyte absorbed was maximised. The chain would continue to produce a voltage until the dowels dried out, then the chain would have to be resoaked. Typically, the chain would be charged by slowly drawing it through a bowl of vinegar as shown in figure 4.<ref>Coley, p.370<br />Lardner, p.289<br />Moritz, pp.97-98<br />Powell, p.21<br />Pulvermacher, pp.2-3</ref>

 

A special link could be included in the chain which incorporated an [[interrupter]] circuit. The purpose of the interrupter is to rapidly connect and disconnect the circuit so that the normally steady current of the battery is turned into a rapidly varying current. The usual practice in the use of medical electrical batteries was to feed the output of the interrupter to an [[induction coil]] in order to increase the voltage applied to the patient by [[transformer]] action. In Pulvermacher's patent however, there is no mention of using induction coils - the Pulvermacher battery could produce large voltages merely by adding more links to the chain. However, the interrupter still had an effect in that an interrupted current produces a stronger sensation of electric shock in the patient than a steady current.<ref>Hemat, p.216</ref> A novel feature of Pulvermacher's interrupter was that it was operated by the action of a vibrating spring kept in motion by the movements of the patient without the need for any external input. Interrupters of the time typically had to be hand-cranked by the physician, although there were already some in existence using electro-mechanical automatic interrupters.<ref>Golding Bird, [https://books.google.com/books?id=6Zp0iSrtvmMC&printsec=frontcover&pg=PA18#v=onepage&q&f=true "Observations on induced electric currents, with a description of a magnetic contact-breaker"], ''Philosophical Magazine'', pp.18-22, no.71, '''vol.12''', January 1838.</ref> Later versions of the Pulvermacher chain used clockwork driven interrupters whose rate of interruption could be adjusted so that the rate of shock to the patient could be controlled. Such a clockwork interrupter is fitted to the chain shown in figure 1. It is wound up by turning the handle at the left end.<ref>Lardner, p.289<br />Pulvermacher, p.2</ref>