ALTERNATING CURRENT

Alper GNEREN - 2010512022Uur KARAAL - 2010512026

ALTERNATING CURRENT

12ALTERNATING CURRENT2hISTORY OF ALTERNATING CURRENTALTERNATING CURRENT3William Stanley, Jr. designed one of the first practical devices to transfer AC power efficiently between isolated circuits. The AC power system used today developed rapidly after 1886, and included contributions by Nikola Tesla and Carl Wilhelm Siemens.

WHAT IS ALTERNATING CURRENT ?ALTERNATING CURRENT4Alternating current electricity is the type of electricity commonly used in homes and businesses throughout the world. AC electricity is created by an AC electric generator, which determines the frequency.An ACwaveformcan be sinusoidal, square, or sawtooth-shaped. Some AC waveforms are irregular or complicated.ALTERNATING CURRENT5Alternating current flows first in one direction and then in the other direction.

This shape show us the current is reversible ...5advantagesALTERNATING CURRENT6The single greatest advantage of alternating current is that AC current can be transformed and DC current cannot be transformed.It can be controlled by a wide range of components eg.resistors,capacitors and inductors.This allows high-voltage electrical power to be distributed with smaller wires and lower amperage.

The electrical power is then transformed to a lower voltage where it is neededIt can be produced directly from generators

6HOW TO GENERATED ?ALTERNATING CURRENT7 DIRECT ALTERNATING ALTERNATING CURRENT8

RMS VALUESALTERNATING CURRENT9Since voltage and current are always changing we need some way of averaging out their effect.We use r.m.s values (root-mean-square)The r.m.s values are the DC values which give the same average power output

ALTERNATING CURRENT10

ac in capacitorsALTERNATING CURRENT11In an AC circuit, the current can continue to flow, as the plates become alternately charged positively and negatively For both AC and DC circuits, the voltage across the resistor is related to the current by V=I.RA similar relationship exists for a capacitor:

reactanceALTERNATING CURRENT12Reactance is a measure of how a capacitor can limit alternating current.It is similar to resistance but differs in that it is dependent on the frequency of the ac supply.It also depends on the size of the capacitor.

IMPEDANCEALTERNATING CURRENT13

Combination resistace and reactans called mpedance13Ac In InductorsALTERNATING CURRENT14.In an AC circuit, the current is always changing so the inductor is always producing an opposing voltage so is always limiting the amount of current that can flow

For both AC and DC circuits, the voltage across the resistor is related to the current by V=IRA similar relationship exists for an inductor

reactanceALTERNATING CURRENT15It measures how well an inductor can limit alternating currentIt depends on the frequency of the ac supply.It depends on the size of the inductor

IMPEDANCEALTERNATING CURRENT16

Phase relatIonshIpALTERNATING CURRENT17

The current in the circuit will always be in phase with VRALTERNATING CURRENT18

The voltage phasors are not necessarily the same size, but are always 90out of phase.

ALTERNATING CURRENT19Again the voltages may be different sizes but will always be 90 out of phase

RLC CIRCUITSALTERNATING CURRENT20The supply voltage is now found by adding all 3 phasors together.(VL and VC are combined into one first)

resonanceALTERNATING CURRENT21At resonance, VL=VC and they cancel each other out. So VS=VR and if VR is at max then I is at max.

referencesALTERNATING CURRENT22http://www.teachersdomain.orghttp://www.peetvs.co.zahttp://www.sjsu.eduhttp://www.youtube.comhttp://www.wikipedia.comhttp://www.upscale.utoronto.caNCEA A.S 3.6 Text Chapters 18-19Yrd. Do. Dr. Levent etin/ alternatif akm

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