Chap 4- Basic Principles of Electricity

8/21/2019 Chap 4- Basic Principles of Electricity

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Basic Principles of ElectricityBasic Principles of Electricity


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ElectromagneticElectromagnetic

SpectrumSpectrumElectrical Stimulating CurrentsElectrical Stimulating Currents

Commercial Radio and TelevisionCommercial Radio and Television

Shortwave DiathermyShortwave DiathermyMicrowave DiathermyMicrowave Diathermy

InfraredInfrared!SER!SER

"isi#le ight "isi#le ight$ltraviolet$ltraviolet

Ioni%ing RadiationIoni%ing Radiation

&&

ongestongest

'avelength'avelength

ShortestShortest

'avelength'avelength

owestowest

(re)uency(re)uency

*ighest*ighest(re)uency(re)uency


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ElectronsElectrons

Particles +f Matter Possessing ! ,egativeParticles +f Matter Possessing ! ,egative

Charge !nd ! Small MassCharge !nd ! Small Mass

,et Movement +f Electrons Is !n Electrical,et Movement +f Electrons Is !n Electrical

CurrentCurrent

Movement +f Electrons Is i-e ! DominoMovement +f Electrons Is i-e ! Domino

ReactionReaction Electrons 'ill Move (rom *igher To owerElectrons 'ill Move (rom *igher To ower

PotentialPotential


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!mpere !mpere

$nit +f Measure 'hich Indicates Rate !t$nit +f Measure 'hich Indicates Rate !t

'hich Electrons (low'hich Electrons (low

. / amp 0 movement of / coulom# or 12345/6/ amp 0 movement of / coulom# or 12345/6/7/7

electrons 8secelectrons 8sec

Current (low Is In Milliamps 9/8/666: +rCurrent (low Is In Milliamps 9/8/666: +r

Microamps 9/8/;666;666:Microamps 9/8/;666;666:


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Electrical Potential DifferenceElectrical Potential Difference

Difference In Concentration of ElectronsDifference In Concentration of Electrons

Between Two PointsBetween Two Points

Electrons 'ill ,ot Move $nless ! PotentialElectrons 'ill ,ot Move $nless ! Potential

Difference E5istsDifference E5ists


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"olt "olt

Creates The Potential DifferenceCreates The Potential Difference

The Electromotive (orce 'hich Must BeThe Electromotive (orce 'hich Must Be

!pplied To Create (low +f Electrons !pplied To Create (low +f Electrons

Commercial Current Is /36 " or 336 " Commercial Current Is /36 " or 336 "


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ConductorsConductors

Materials That Permit (ree Movement ofMaterials That Permit (ree Movement of

ElectronsElectrons

Composed +f arge ,um#ers of (ree ElectronsComposed +f arge ,um#ers of (ree Electrons

+ffer ittle Resistance To Current (low+ffer ittle Resistance To Current (low


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InsulatorsInsulators

Materials That Resist The (low +f ElectronsMaterials That Resist The (low +f Electrons

Contain (ew (ree ElectronsContain (ew (ree Electrons

Insulator MaterialsInsulator Materials

. !ir; 'ood;


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Resistance 0 Electrical ImpedanceResistance 0 Electrical Impedance

+pposition To (low +f Electrical Current+pposition To (low +f Electrical Current

Measured In +hmsMeasured In +hms

+hm=s aw+hm=s aw Current (low0Current (low0 "oltage "oltage

ResistanceResistance


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'att'att

Measure of Electrical PowerMeasure of Electrical Power

'atts 0 "olts > !mps'atts 0 "olts > !mps

Modalities $se Milliamps or MicroampsModalities $se Milliamps or Microamps


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Electrotherapeutic CurrentsElectrotherapeutic Currents

Direct 9DC: or MonophasicDirect 9DC: or Monophasic

. (low of Electrons !lways In Same Direction(low of Electrons !lways In Same Direction

. Sometimes Called


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Electrotherapeutic CurrentElectrotherapeutic Current

!lternating 9!C: or Biphasic !lternating 9!C: or Biphasic

. (low of Electrons Changes Direction(low of Electrons Changes Direction ? !lways (lows (rom ,egative to Positive Pole $ntil Polarity Is !lways (lows (rom ,egative to Positive Pole $ntil Polarity Is

ReversedReversed


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Pulsed or PolyphasicPulsed or Polyphasic

. Pulses


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Electrical


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,o Relationship Between Type +f Current,o Relationship Between Type +f Current

$sed To Power


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'aveform or Pulse'aveform or Pulse

Pulse0 IndividualPulse0 Individual

'aveform'aveform

Phases 9Duration:Phases 9Duration: Interpulse IntervalInterpulse Interval

Direction 9Polarity:Direction 9Polarity:

!mplitude !mplitude

Rate +f RiseRate +f Rise

Rate of DecayRate of Decay

. !ccommodation !ccommodation


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Symmetrical 'aveformsSymmetrical 'aveforms

SineSine

S)uareS)uare TriangularTriangular


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Symmetrical 'aveformsSymmetrical 'aveforms

Twin Pea-edTwin Pea-ed

Triangular 'aveformTriangular 'aveform

. (ound on Most *igh(ound on Most *igh

"olt


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!symmetric 'aveforms !symmetric 'aveforms

(aradic(aradic

E5ponentialE5ponential

. SawtoothSawtooth


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Current ModulationCurrent Modulation

ContinuousContinuous

InterruptedInterrupted

BurstBurst. Pac-etsPac-ets

. Pulse TrainsPulse Trains

. BeatsBeats Ramped 9Surge:Ramped 9Surge:


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Pulse !mplitudePulse !mplitude

Same !s Intensity or "oltageSame !s Intensity or "oltage

Measured In Milliamps or MicrovoltsMeasured In Milliamps or Microvolts !verage Current Determined By Interpulse !verage Current Determined By Interpulse

Interval +r Current DurationInterval +r Current Duration


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Pulse DurationPulse Duration

ength +f Time Current Is (lowingength +f Time Current Is (lowing

'ith Monophasic Current Phase Duration Is'ith Monophasic Current Phase Duration Is

the Same !s Pulse Durationthe Same !s Pulse Duration 'ith Biphasic Current Pulse Duration Is'ith Biphasic Current Pulse Duration Is

Determined By The Com#ined Phase DurationsDetermined By The Com#ined Phase Durations

'ith Polyphasic Current The Com#ined Pulse'ith Polyphasic Current The Com#ined PulseDuration !nd Interpulse Interval Is The PulseDuration !nd Interpulse Interval Is The Pulse

PeriodPeriod


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Pulse (re)uency 9CPS; PPS; *%:Pulse (re)uency 9CPS; PPS; *%:

Effects The Type +f Muscle ContractionEffects The Type +f Muscle Contraction

Effects The Mechanism of Pain ModulationEffects The Mechanism of Pain Modulation


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Electrical CircuitsElectrical Circuits

Path of Current (rom Power Source ThroughPath of Current (rom Power Source Through

"arious Components Bac- To


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Series CircuitSeries Circuit

+ne Path (or Current To Ta-e+ne Path (or Current To Ta-e

Component Resistors Placed End To EndComponent Resistors Placed End To End

Total Resistance 0 Sum of ResistancesTotal Resistance 0 Sum of Resistances

Total "oltage 0 Sum of "oltage DecreasesTotal "oltage 0 Sum of "oltage Decreases


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Parallel CircuitParallel Circuit

Component Resistors Placed Side to Side 'ith EndsComponent Resistors Placed Side to Side 'ith Ends

ConnectedConnected Current Chooses Path 'ith east ResistanceCurrent Chooses Path 'ith east Resistance

Resistors *ave ower Resistance But *igher Current (lowResistors *ave ower Resistance But *igher Current (low

Than ! Series CircuitThan ! Series Circuit


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Current (low Through BiologicCurrent (low Through Biologic

TissuesTissues

Com#ination +f Both Series !nd Parallel CircuitsCom#ination +f Both Series !nd Parallel Circuits

Tissue *ighest In 'ater !nd Ion Content BestTissue *ighest In 'ater !nd Ion Content Best

Conductors A Blood; ,erve; Muscle; Tendon; S-in;Conductors A Blood; ,erve; Muscle; Tendon; S-in;

(at; Bone(at; Bone


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Safety In $sing ElectricalSafety In $sing Electrical

E)uipmentE)uipment


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Chap 4- Basic Principles of Electricity