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Indian Institute of Technology, K
ROBOTIX
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W
BASIC PHYS
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THINGS TO BE COVERED
BASIC ELECTRICITY INTRODUCTION TO CAPACITANCE
WORKING OF A MOTOR
INTRODUCTION TO ALTERNATING CURRENT BASIC DIODES
TRANSFORMERS
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W
BASIC ELECTRI
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BASIC ELECTRICITY
What is electric current? Why do we need it?
Why do we get shocks due to it?
What are circuits? How many types of Electric current are ther
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BASIC ELECTRICITY
What is electric potential? What is Potential Difference?
What is Ohms Law?
What are Kirchoffs Current Laws?
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What is Electric Current?
Flow of charge though a conductor. Calculation:
where Q is the total charge and t is the total time.
Unit of Charge is Coulomb (C) and Electricity is A
1 A = 1 C/ 1 S
(?) Charge of an Electron?
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What is Electric Current?
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Why do we need it?
All of appliances around us are based on it We need it to power lights, fans, TVs, Proje
PCs etc..
All of us know how does it feel when powerout?
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Electric Shocks
An electric shock occurs upon contact of a humanany source of voltage high enough
sufficient current through the skin, muscles or hair. Th
current a human can feel is thought to
1 milliampere (mA). The current may cause tissu
or fibrillation if it is sufficiently high. Death cau
electric shock is referred to as electrocution. Genera
approaching 100 mA are lethal if they pass throug
portions of the body
http://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Fibrillationhttp://en.wikipedia.org/wiki/Electrocutionhttp://en.wikipedia.org/wiki/Electrocutionhttp://en.wikipedia.org/wiki/Fibrillationhttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Voltage8/9/2019 2. Basic Physics
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Circuits
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Circuits
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Types of Electric Current
Electric Current are of two types:
Direct Current (DC)
Alternating Current (AC)
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Direct Current
Direction and Magnitude do not change w Used in torches, battery operated toys, rem
controls, and ROBOTS!
NOT used in supply lines due to TRANSMISLOSSES.
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Alternating Current
Direction and Magnitude constantly changtime. (Generally sine or cosine wave funct
Used in power lines, home appliances.
Comparatively less power loss during trans Can be stepped up and down.
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Electric Shocks
Generally, we use DC in robots, as most oelectronic components like ICs work on DC
A Voltage Range of 5V - 12V is used gen
robots.
At that range, there are low chances of sh
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Electric Potential
Every job requires some WORK to be done Similarly, the moving of charges in a curren
requires some work to be done.
Work done in bringing a unit positive charginfinity to a point, is called potential of that
The SI unit of Potential is Volts (V), named a
famous scientist Alessandro Volta.
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Electric Potential
Potential is relative. Potential of a point is defined b
considering the potential to be zero at infinity.
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Potential Difference
As the name suggest, the difference in the pbetween two points.
Represented as V [Delta V].
Vbetween two points one and two arV12 = V2 V1
Also, V12 = (-)W12 / Q
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Potential Difference
As water current moves from high to low levto gravity, similarly, Electric Current moves f
High Potential to Low Potential.
Therefore, in the direction of current, there
a decrease of potential across any compon
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OHMs Law
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USES OF OHMs LAW
In robotics, we generally use Ohms law to the current flow in a branch.
Appropriate value of Resistors are used, to
required current.
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RESISTANCE
Resistance is a constant used in Ohms law. It is a property of the material and hence v
across materials.
It also depends on the shape and size of aconductor.
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POTENTIAL DIFFERENCE ACROSS RES
V= I x R
We know that moving in the direction o
current causes potential to decrease.
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POTENTIAL DIFFERENCE ACROSS RES
VAC = -I x R1I x R2
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CONDUCTORS, INSULATORS AND SEMI- COND
CONDUCTORS : Materials through which ccan flow.
INSULATORS : Materials through which cur
flow.
SEMI CONDUCTORS : Materials which of
resistance intermediate between the conduc
insulators. Widely used in Electronics Indust
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SUPER - CONDUCTORS
Materials which provide absolutely no resisthe electric current flowing through it.
Example : Few Ceramics
In Problem solving, unless resistance is not swires and components are assumed to be m
super conducting materials. (R = 0)
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SUPER - CONDUCTORS
Since R=0, across super conductors, therefopotential difference across the wires would
V= 0 x I
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KIRCHOFFs CURRENT LAWS
Kirchoffs rules help us determine the magnand direction of current in different branch
circuit.
There are two Kirchoffs Current laws.
JUNCTION RULE (Kirchoffs Current Law)
LOOP RULE (Kirchoffs Voltage Law)
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JUNCTION RULE (Kirchoffs Curre
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JUNCTION
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SALIENT POINTS JUNCTION R
There is no loss (sink) of current at any junct Current entering a junction = Current leavin
junction.
Also known as KCL.
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LOOP RULE(Kirchoffs Voltage
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KIRCHOFFs RULE - EXAMPLE
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CAPACITANC
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CAPACITANCE
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CAPACITANCE
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CAPACITANCE
For our purposes, we use capacitance in reccircuit to normalize the current.
It is used for conversion from Alternating Cu
Direct Current.
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MOT
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WORKING OF A MOTOR
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WORKING OF A MOTOR
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ALTERNATING CUR
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Alternating Current
Direction and Magnitude constantly changtime. (Generally sine or cosine wave funct
Used in power lines, home appliances.
Comparatively less power loss during trans
Can be stepped up and down.
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GRAPH OF ALTERNATING CURR
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DIO
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ABOUT DIODES
A diode is a two-terminal electronic compoconducts electric current in only one directio
Thus, the diode can be thought of as an
version of a check valve. This unid
behavior is called rectification, and isconvert alternating current to direct curren
extract modulation from radio signals
receivers.
ABOUT DIODES
http://en.wikipedia.org/wiki/Terminal_(electronics)http://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Check_valvehttp://en.wikipedia.org/wiki/Rectification_(electricity)http://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Rectification_(electricity)http://en.wikipedia.org/wiki/Check_valvehttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Terminal_(electronics)8/9/2019 2. Basic Physics
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ABOUT DIODES
COMMON DIODES
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COMMON DIODES
Light-emitting diodes (LEDs)
In a diode formed from a direct band-gap semiconductor, such as ga
carriers that cross the junction emit photons when they recombine wi
carrier on the other side. Depending on the material, wavelengths (or
the infrared to the near ultraviolet may be produced[12]. The forwa
these diodes depends on the wavelength of the emitted photons: 1.2
to red, 2.4 V to violet. The first LEDs were red and yellow, and hig
diodes have been developed over time. All LEDs produce incoh
spectrum light; white LEDs are actually combinations of three LEDs
color, or a blue LED with a yellow scintillator coating. LEDs can also b
efficiency photodiodes in signal applications. An LED may be
photodiode or phototransistor in the same package, to form an opto-
http://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Direct_bandgaphttp://en.wikipedia.org/wiki/Gallium_arsenidehttp://en.wikipedia.org/wiki/Photonshttp://en.wikipedia.org/wiki/Wavelengthhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Ultraviolethttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Scintillatorhttp://en.wikipedia.org/wiki/Opto-isolatorhttp://en.wikipedia.org/wiki/Opto-isolatorhttp://en.wikipedia.org/wiki/Scintillatorhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Ultraviolethttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Wavelengthhttp://en.wikipedia.org/wiki/Photonshttp://en.wikipedia.org/wiki/Gallium_arsenidehttp://en.wikipedia.org/wiki/Direct_bandgaphttp://en.wikipedia.org/wiki/Light-emitting_diode8/9/2019 2. Basic Physics
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TRANSFORM
TRANSFORMERS
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TRANSFORMERS
A transformer is a device that transfers electrical en
one circuit to another through inductively coupled co
the transformer's coils. A varying current in the first
or primarywinding creates a varying magnetic flux
transformer's core, and thus a varying magnetic field
the secondarywinding. This varying magnetic field invarying electromotive force (EMF) or "voltage" in the
secondary winding. This effect is called mutual induc
STEPPING UP AND DOWN
http://en.wikipedia.org/wiki/Electrical_energyhttp://en.wikipedia.org/wiki/Electrical_networkhttp://en.wikipedia.org/wiki/Inductive_couplinghttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Magnetic_fluxhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Electromagnetic_inductionhttp://en.wikipedia.org/wiki/Electromotive_forcehttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Mutual_inductionhttp://en.wikipedia.org/wiki/Mutual_inductionhttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Electromotive_forcehttp://en.wikipedia.org/wiki/Electromagnetic_inductionhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fluxhttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Inductive_couplinghttp://en.wikipedia.org/wiki/Electrical_networkhttp://en.wikipedia.org/wiki/Electrical_energy8/9/2019 2. Basic Physics
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STEPPING UP AND DOWN
STEPPING UP AND DOWN
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STEPPING UP AND DOWN
The conversion Relation :
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END OF S