- Direct current (DC) flows in one direction, while alternating current (AC) varies in both magnitude and direction over time, typically following a sinusoidal waveform.
- The key characteristics of an AC waveform are its period, frequency, and amplitude. The period is the time it takes to complete one cycle, frequency is the number of cycles per second, and amplitude is the maximum voltage or current value.
- Common AC waveforms include sinusoidal, square, and triangular waves. The domestic power supply typically uses a 50Hz or 60Hz sinusoidal waveform.
This ppt provides a brief overview on thyristors commonly known as SCRs. V- I characteristics curve, triggering methods, protection methods, series and parallel operations of SCRs, applications are discussed in this slide.
Two port network parameters, Z, Y, ABCD, h and g parameters, Characteristic impedance,
Image transfer constant, image and iterative impedance, network function, driving point and
transfer functions – using transformed (S) variables, Poles and Zeros.
This ppt provides a brief overview on thyristors commonly known as SCRs. V- I characteristics curve, triggering methods, protection methods, series and parallel operations of SCRs, applications are discussed in this slide.
Two port network parameters, Z, Y, ABCD, h and g parameters, Characteristic impedance,
Image transfer constant, image and iterative impedance, network function, driving point and
transfer functions – using transformed (S) variables, Poles and Zeros.
The presentation describes construction and working of CRT/ CRO's. Measurement of Voltage, frequency and phase using CRO is described. Presentation describes X-Y display, Lissajou figures and Z axis modulation of CRO's. Delay time based CRO', Sampling CRO, DSO and DSO applications are explained.
This presentation contains the basic information you need to know about operational amplifier.
I have tried to cover all the basic info. If anything is left out or you have any suggestions i will appreciate it.
Generalized network constants and equivalent circuits of short, medium, long transmission line. Line performance: regulation and efficiency, Ferranti effect.
This Presentation can be used by the Students of Engineering who Deals with the Subject ELECTRICAL MACHINES and use it for Refrence (Anyways you Guys will Copy Paste or Download it) ;)
The presentation describes construction and working of CRT/ CRO's. Measurement of Voltage, frequency and phase using CRO is described. Presentation describes X-Y display, Lissajou figures and Z axis modulation of CRO's. Delay time based CRO', Sampling CRO, DSO and DSO applications are explained.
This presentation contains the basic information you need to know about operational amplifier.
I have tried to cover all the basic info. If anything is left out or you have any suggestions i will appreciate it.
Generalized network constants and equivalent circuits of short, medium, long transmission line. Line performance: regulation and efficiency, Ferranti effect.
This Presentation can be used by the Students of Engineering who Deals with the Subject ELECTRICAL MACHINES and use it for Refrence (Anyways you Guys will Copy Paste or Download it) ;)
Alternating Current -12 isc 2017 ( investigatory Project) Student
In this file, we will study about the various types of ac circuits, how they work,their phasor diagrams,types of periodic form,analytical method and graphical method to find average value of alternating current.
Alternating current (AC), is an electric current in which the flow of electric charge periodically reverses direction, whereas in direct current (DC, also dc), the flow of electric charge is only in one direction.
One wave per second is also called a Hertz Hz and in SI units is a reciprocal second s 1 . The variable c is the speed of light. For the relationship to hold mathematically, if the speed of light is used in m s, the wavelength must be in meters and the frequency in Hertz. So what would be frequency of DC waveform weather it’s 0 HZ or more than 0 HZ up to 1 HZ Natvarbhai P Gajjar "Electrical DC Waveform Frequency" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd45018.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/45018/electrical-dc-waveform-frequency/natvarbhai-p-gajjar
NETWORK ANALYSIS PART 3 For GATE IES PSU -2020 RRB/SSC AE JE TECHNICAL INT...Prasant Kumar
for youtube video visit link
https://youtu.be/eq5UnA1e17E
Single phase AC circuits is most basic and important portion topic for GATE,IES,PSU,SSC,and different state level examinations.which covers following topics.1-Phase AC Circuits,AC & DC SIGNALS,Differentiate AC vs DC signal,PROPERTIES OF AC SIGNALS,peak value and peak to peak value,average value,R.M.S. value,instantaneous value,form factor,peak factor,WAVEFORM ANALYSIS OF AC SIGNAL,advantages of sinusoidal waveform,cycle, time periods and frequency,Phasor,Differentiate between Active, Reactive and Apparent Power,power triangle ,MCQ FOR PRACTICES,unilateral circuit ,bilateral circuit , irreversible circuit , reversible circuit series with each other , parallel with each other , series with the voltage source., parallel with the voltage source ,linear network , non-linear network , passive network , active network
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Alternating current signal
AC means Alternating Current and DC means Direct Current. AC and DC are also used when referring to voltages and electrical signals which are not currents! For example: a 12V AC power supply has an alternating voltage (which will make an alternating current flow).
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
1. Home / AC Circuits / AC Waveform and AC Circuit Theory
AC Waveform and AC Circuit Theory
Direct Current or D.C. as it is more commonly called, is a form of electrical current or voltage
that 漀琀ows around an electrical circuit in one direction only, making it a “Uni-directional”
supply.
Generally, both DC currents and voltages are produced by power supplies, batteries,
dynamos and solar cells to name a few. A DC voltage or current has a 爀xed magnitude
(amplitude) and a de 爀nite direction associated with it. For example, +12V represents 12 volts
in the positive direction, or -5V represents 5 volts in the negative direction.
We also know that DC power supplies do not change their value with regards to time, they
are a constant value 漀琀owing in a continuous steady state direction. In other words, DC
maintains the same value for all times and a constant uni-directional DC supply never
changes or becomes negative unless its connections are physically reversed. An example of a
simple DC or direct current circuit is shown below.
DC Circuit and Waveform
2. An alternating function or AC Waveform on the other hand is de 爀ned as one that varies in
both magnitude and direction in more or less an even manner with respect to time making it
a “Bi-directional” waveform. An AC function can represent either a power source or a signal
source with the shape of an AC waveform generally following that of a mathematical
sinusoid as de 爀ned by:- A(t) = A x sin(2πƒt).
The term AC or to give it its full description of Alternating Current, generally refers to a
time-varying waveform with the most common of all being called a Sinusoid better known
as a Sinusoidal Waveform. Sinusoidal waveforms are more generally called by their short
description as Sine Waves. Sine waves are by far one of the most important types of AC
waveform used in electrical engineering.
The shape obtained by plotting the instantaneous ordinate values of either voltage or
current against time is called an AC Waveform. An AC waveform is constantly changing its
polarity every half cycle alternating between a positive maximum value and a negative
maximum value respectively with regards to time with a common example of this being the
domestic mains voltage supply we use in our homes.
This means then that the AC Waveform is a “time-dependent signal” with the most
common type of time-dependant signal being that of the Periodic Waveform. The periodic
or AC waveform is the resulting product of a rotating electrical generator. Generally, the
shape of any periodic waveform can be generated using a fundamental frequency and
superimposing it with harmonic signals of varying frequencies and amplitudes but that’s for
another tutorial.
Alternating voltages and currents can not be stored in batteries or cells like direct current
(DC) can, it is much easier and cheaper to generate these quantities using alternators or
waveform generators when they are needed. The type and shape of an AC waveform depends
upon the generator or device producing them, but all AC waveforms consist of a zero voltage
line that divides the waveform into two symmetrical halves. The main characteristics of an
AC Waveform are de 爀ned as:
AC Waveform Characteristics
max
3. • The Period, (T) is the length of time in seconds that the waveform takes to repeat
itself from start to 爀nish. This can also be called the Periodic Time of the waveform for
sine waves, or the Pulse Width for square waves.
• The Frequency, (ƒ) is the number of times the waveform repeats itself within a one
second time period. Frequency is the reciprocal of the time period, ( ƒ = 1/T ) with the
unit of frequency being the Hertz, (Hz).
• The Amplitude (A) is the magnitude or intensity of the signal waveform measured
in volts or amps.
In our tutorial about ,we looked at di 攀erent types of waveforms and said that
“Waveforms are basically a visual representation of the variation of a voltage or current
plotted to a base of time”. Generally, for AC waveforms this horizontal base line represents
a zero condition of either voltage or current. Any part of an AC type waveform which lies
above the horizontal zero axis represents a voltage or current 漀琀owing in one direction.
Likewise, any part of the waveform which lies below the horizontal zero axis represents a
voltage or current 漀琀owing in the opposite direction to the 爀rst. Generally for sinusoidal AC
waveforms the shape of the waveform above the zero axis is the same as the shape below it.
However, for most non-power AC signals including audio waveforms this is not always the
case.
The most common periodic signal waveforms that are used in Electrical and Electronic
Engineering are the Sinusoidal Waveforms. However, an alternating AC waveform may not
always take the shape of a smooth shape based around the trigonometric sine or cosine
function. AC waveforms can also take the shape of either Complex Waves, Square Waves or
Triangular Waves and these are shown below.
Types of Periodic Waveform
Waveforms
4. The time taken for an AC Waveform to complete one full pattern from its positive half to its
negative half and back to its zero baseline again is called a Cycle and one complete cycle
contains both a positive half-cycle and a negative half-cycle. The time taken by the
waveform to complete one full cycle is called the Periodic Time of the waveform, and is
given the symbol “T”.
The number of complete cycles that are produced within one second (cycles/second) is called
the Frequency, symbol ƒ of the alternating waveform. Frequency is measured in Hertz, ( Hz )
named after the German physicist Heinrich Hertz.
Then we can see that a relationship exists between cycles (oscillations), periodic time and
frequency (cycles per second), so if there are ƒ number of cycles in one second, each
individual cycle must take 1/ƒ seconds to complete.
Relationship Between Frequency and Periodic Time
5. AC Waveform Example No1
1. What will be the periodic time of a 50Hz waveform and 2. what is the frequency of an AC
waveform that has a periodic time of 10mS.
1).
2).
Frequency used to be expressed in “cycles per second” abbreviated to “cps”, but today it is
more commonly speci 爀ed in units called “Hertz”. For a domestic mains supply the
frequency will be either 50Hz or 60Hz depending upon the country and is 爀xed by the speed
of rotation of the generator. But one hertz is a very small unit so pre 爀xes are used that
denote the order of magnitude of the waveform at higher frequencies such as kHz, MHz and
even GHz.
Denition of Frequency Prexes
Pre 爀x De 爀nition Written as Periodic Time
Kilo Thousand kHz 1ms
Mega Million MHz 1us
Giga Billion GHz 1ns
Terra Trillion THz 1ps
Amplitude of an AC Waveform
As well as knowing either the periodic time or the frequency of the alternating quantity,
another important parameter of the AC waveform is Amplitude, better known as its
Maximum or Peak value represented by the terms, Vmax for voltage or Imax for current.
6. The peak value is the greatest value of either voltage or current that the waveform reaches
during each half cycle measured from the zero baseline. Unlike a DC voltage or current
which has a steady state that can be measured or calculated using , an
alternating quantity is constantly changing its value over time.
For pure sinusoidal waveforms this peak value will always be the same for both half cycles
( +Vm = -Vm ) but for non-sinusoidal or complex waveforms the maximum peak value can
be very di 攀erent for each half cycle. Sometimes, alternating waveforms are given a peak-
to-peak, Vp-p value and this is simply the distance or the sum in voltage between the
maximum peak value, +Vmax and the minimum peak value, -Vmax during one complete
cycle.
The Average Value of an AC Waveform
The average or mean value of a continuous DC voltage will always be equal to its maximum
peak value as a DC voltage is constant. This average value will only change if the duty cycle
of the DC voltage changes. In a pure sine wave if the average value is calculated over the full
cycle, the average value would be equal to zero as the positive and negative halves will cancel
each other out. So the average or mean value of an AC waveform is calculated or measured
over a half cycle only and this is shown below.
Average Value of a Non-sinusoidal Waveform
Ohm’s Law
7. To 爀nd the average value of the waveform we need to calculate the area underneath the
waveform using the mid-ordinate rule, trapezoidal rule or the Simpson’s rule found
commonly in mathematics. The approximate area under any irregular waveform can easily
be found by simply using the mid-ordinate rule.
The zero axis base line is divided up into any number of equal parts and in our simple
example above this value was nine, ( V to V ). The more ordinate lines that are drawn the
more accurate will be the 爀nal average or mean value. The average value will be the addition
of all the instantaneous values added together and then divided by the total number. This is
given as.
Average Value of an AC Waveform
Where: n equals the actual number of mid-ordinates used.
For a pure sinusoidal waveform this average or mean value will always be equal to
0.637 x V and this relationship also holds true for average values of current.
The RMS Value of an AC Waveform
The average value of an AC waveform is NOT the same value as that for a DC waveforms
average value. This is because the AC waveform is constantly changing with time and the
heating e 攀ect given by the formula ( P = I .R ), will also be changing producing a positive
power consumption. The equivalent average value for an alternating current system that
provides the same power to the load as a DC equivalent circuit is called the “e 攀ective value”.
This e 攀ective power in an alternating current system is therefore equal to: ( I .R.Average ).
As power is proportional to current squared, the e 攀ective current, I will be equal to √ I
squared Ave. Therefore, the e 攀ective current in an AC system is called the Root Mean Squared
or R.M.S. value and RMS values are the DC equivalent values that provide the same power to
the load.
The e 攀ective or RMS value of an alternating current is measured in terms of the direct
current value that produces the same heating e 攀ect in the same value resistance. The RMS
value for any AC waveform can be found from the following modi 爀ed average value formula.
RMS Value of an AC Waveform
1 9
max
2
2
8. Where: n equals the number of mid-ordinates.
For a pure sinusoidal waveform this e 攀ective or R.M.S. value will always be equal to 1/
√2 x V which is equal to 0.707 x V and this relationship holds true for RMS values of
current. The RMS value for a sinusoidal waveform is always greater than the average value
except for a rectangular waveform. In this case the heating e 攀ect remains constant so the
average and the RMS values will be the same.
One 爀nal comment about R.M.S. values. Most multimeters, either digital or analogue unless
otherwise stated only measure the R.M.S. values of voltage and current and not the average.
Therefore when using a multimeter on a direct current system the reading will be equal to
I = V/R and for an alternating current system the reading will be equal to Irms = Vrms/R.
Also, except for average power calculations, when calculating RMS or peak voltages, only use
V to 爀nd I values, or peak voltage, Vp to 爀nd peak current, Ip values. Do not mix the
two together average, RMS or peak values as they are completely di 攀erent and your results
will be incorrect.
Form Factor and Crest Factor
Although little used these days, both Form Factor and Crest Factor can be used to give
information about the actual shape of the AC waveform. Form Factor is the ratio between
the average value and the RMS value and is given as.
For a pure sinusoidal waveform the Form Factor will always be equal to 1.11. Crest Factor is
the ratio between the R.M.S. value and the Peak value of the waveform and is given as.
For a pure sinusoidal waveform the Crest Factor will always be equal to 1.414.
max max
RMS RMS
9. AC Waveform Example No2
A sinusoidal alternating current of 6 amps is 漀琀owing through a resistance of 40Ω. Calculate
the average voltage and the peak voltage of the supply.
The R.M.S. Voltage value is calculated as:
The Average Voltage value is calculated as:
The Peak Voltage value is calculated as:
The use and calculation of Average, R.M.S, Form factor and Crest Factor can also be use with
any type of periodic waveform including Triangular, Square, Sawtoothed or any other
irregular or complex voltage/current waveform shape. Conversion between the various
sinusoidal values can sometimes be confusing so the following table gives a convenient way
of converting one sine wave value to another.
Sinusoidal Waveform Conversion Table
Convert From Multipy By Or By To Get Value
Peak 2 (√2) Peak-to-Peak
Peak-to-Peak 0.5 1/2 Peak
Peak 0.7071 1/(√2) RMS
2
10. Peak 0.637 2/π Average
Average 1.570 π/2 Peak
Average 1.111 π/(2√2) RMS
RMS 1.414 √2 Peak
RMS 0.901 (2√2)/π Average
In the next tutorial about we will look at the principal of generating a
sinusoidal AC waveform (a sinusoid) along with its angular velocity representation.
Sinusoidal Waveforms
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11. R
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Rstna singh
What is the conclusion of where the frequency and maximum value of voltage of ac sine value takes
place?
alabhaya tandon
thanks for clearing most my doubts how ever I still have one more doubt .
if the amplitude of ac is always varying , is the frequency �xed ?
Wayne Storr
While the amplitude of an AC waveform varies as the alternator rotates within a magnetic
�eld. The frequency is �xed as it relates to the alternators rotational speed.
cengineer123
thanks for this.it was great. you help me to understand better and I try it in circuits cloud
it is a very good website.
Debbie
One of the best and easiest to understand explanations I’ve come across. Thank you
Posted on September 14th 2016 | 3:28 am
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g
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Xysa
Thanks for this!
gunasekhar
good
gopikkannankt
thankyou your kind e ┃ort…..
Richard Comerford
You’re welcome
Diode1996
Nice ever!
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Pradeep
Very Nice Post.
Can you show me how increase e 漄cency of DC-DC converter SG3525 and reduce temparature on each
MOSFET?
I think that i should forced turn o ┃ MOSFET with negative voltage? But i havent konwn yet what i
should do?
Plz help me.
Also Visit My Website Click Here
Saumya
What does it mean when “one half cycle of p.d.”
Posted on February 28th 2016 | 6:27 pm
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