galvanic currents

Galvanic CurrentsGalvanic Currents

Dr.Deepak Anap,Asso. Professor

COPT,PDVVPF

[email protected]

Galvanic Currents - Dr.Deepak

Objectives • History

• Introduction to DC

• Graphical Representation

• Interrupted DC

• Wave form Characteristics – Duration and Frequency

• IDC Waveforms


History

• Luigi Galvani ,an Italian Physiologist-on whose honor galvanic current is named.

• First to show that when electric current is passed through the legs of a frog, it twitched, way back in 1791.


http://www.english.upenn.edu/Projects/knarf/People/galvani.html

Definition

• In DC, electrical current flows in one constant direction, as opposed to AC, in which the current constantly reverses direction.

• Ex of a device that provides DC : battery. • DC ultimately supplies power to nearly all

electronic devices (even if these devices require a component to convert AC current into DC current).


DC Vs AC


Modifications of DC

• Interruption – most usual modification of DC

• Interrupted DC

• Current flow commencing & ceasing at

regular intervals


Wave form Characteristics

• Duration

• Duration 100,300,600ms used for Treatment with IDC


Duration

• Frequency: No. of impulses/Sec• Depends on duration of Interval between the

impulses• Duration α 1/Frequency


Duration of interval

IDC waveforms


DC

Rectangular IDC

Current rises suddenly, constantly maintained for the duration of the stimulus then turned off abruptly

Triangular Pulses

• Traingular: has an equal phase of slow rise and then slow falling off in intensity


Trapezoidal Pulses

Current rises slowly, plateaus for a short period then gradually declines


Saw Tooth Pulses

current is gradually raised then turned off abruptly


Depolarised Wave Form

• Current of low intensity flows in reverse direction

• Chemical formation because of DC is reduced


Thank you

galvanic currents

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