Transcript chapter 1 - UniMAP Portal

CHAPTER 1
ELECTRICAL CONTROLLER
EQUIPMENT
BY:
Salsabila Ahmad
ELECTRICAL CIRCUIT BASIC
4 ELECTRICAL BASICS
 POWER SUPPLY
 INPUT DEVICE
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Input Controller Equipment
CONDUCTOR
OUTPUT DEVICE
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Output Controller Equipment
POWER SUPPLY
Definition:
 A device which supplies energy needed to
create an electrical current
INPUT DEVICE
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DEFINITION
2 TYPES OF INPUT DEVICE
 Mechanical input device
 Solid state proximity device
ELECTRICAL SWITCHING
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Basic Principle of Electrical Switching
Types of Contacts
How do These Contacts Work?
DEFINITION:
A device which allows/ controls the flow of
current in a circuit
 These devices are known as
“ELECTRICAL CONTROLLER EQUIPMENTS”
 Provides Electrical Switching

MECHANICAL INPUT DEVICES
Definition:
 An input device with a mechanical
contact
SOLID STATE PROXIMITY
DEVICES
Definition:
 An electronic input device which
needs power to be able to operate
 EG Various types of sensors
EXAMPLE OF MECHANICAL INPUT
DEVICES
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Contact Relay
Push button
Limit Switch
Selector Switch
Toggle Switch
Temperature Switch
Pressure Switch
Solenoid Switch
Induction Motor Controller
PROXIMITY SENSORS CATEGORY
Proximity sensors
inductive
capacitive
dielectric type
conductive type
ultrasonic
optical
diffuse reflective type
retro reflective type
thru beam
fiber optic sensor
color mark sensor
encoder sensor
RELAY
2 TYPES OF RELAY:
 EMR
 SSR
ELECTROMAGNETIC RELAY
(EMR)
Definition:
 An EMR is an electromagnetic device
composed of a frame/core,
electromagnet coil and contacts
(move and fixed)
 Based on simple electromagnetic
principle
SOLID STATE RELAY (SSR)
HOW IT OPERATES?
 Operates similarly to EMR, but with
no mechanical contact.
 Employ semiconductor switching
elements such as thryristors, triacs,
diodes and transistors.
Employ optical semiconductors called
photo couplers to isolate input and
output signals.
 Photo couplers change electrical to
optical signals and relay the signal
through space.

CHARACTERISTICS OF EMR AND SSR
EMR
slow
speed
wears out easily
Noisy
Cheap
SSR
high
speed, high
frequency for switching
operations
no failure due to wear
out, since no mechanical
contacts
little noise
Expensive
RELAY SYMBOLS

Most common relay symbols used in electrical
machine diagram
Normally open
(NO)
Normally close
(NC)
Coil
BASIC PRINCIPLE OF ELECTRICAL
SWITCHING
A situation of breaking and open an
electrical circuit
 Or to direct current from one
conductor to another.
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The PLC is the solution to today’s
electrical switching requirements
 where it is able to solve complex
switching requirements.
2 TYPES OF CONTACT
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NO
NC
HOW DO THESE CONTACTS
WORK?
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Once coil is energized, the contact
will change state
 NO  NC
 NC  NO
SOLENOID SWITCH
Use concept of magnetic flux for
armature/plunger to move
 Produces linear mechanical motion

PUSH BUTTON
DEFINITION
 pushbutton-type operator
 Have one set or more contact/spring
 Mostly have a set of normally open (NO)
and normally closed (NC) contact
CONCEPTS OF OPERATION
Pushing the operator causes the
contacts to change state
 Spring causes switch operator to
automatically return to it’s natural
state when it is released.
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NO

NC

NC

NO

natural state change state
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NO
NC
automatic return
a switch with this return spring action, is
called a momentary switch.
APPLICATIONS
Frequently used in industrial
applications to control functions such
as
 starting
 and stopping
the machine’s operation
 With a safety nature. Why?
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SCHEMATIC SYMBOLS FOR PUSH
BUTTON
Normally Open Contact
Normally Closed Contact
SELECTOR SWITCH
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Similarly to pushbutton, but instead of
pushing, you rotate a knob
may be designed to stay in a selected
position or may have a momentary
action
selector switch that stays in a certain
position is called a maintained switch.
APPLICATION
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Widely used in industrial applications
 for switching mode of operation
 to turn the main power on and off
 to select between AC or DC output.
Some requires key (authorized person) to
turn on for safety reason.
SCHEMATIC SYMBOLS FOR
SELECTOR SWITCH
Normally open
contact
Normally close
contact
Selector switch with
two contacts
TOGGLE SWITCH
Toggle switch is a maintained switch
INDUCTION MOTOR CONTROLLER
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Commonly used micro-controllers
PROXIMITY
SENSORS
INDUCTIVE PROXIMITY SENSOR
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Sense only metallic objects
 e.g. steel, iron, aluminum, tin, copper etc
Has limited sensing range
 range affected by the type of metal
sense
CAPACITIVE PROXIMITY SENSOR
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sense all material with mass.
operation for both dielectric and
conductive type are the same
The dielectric type works best for high
density material
 Low density material (e.g. paper, foam
etc) do not cause a detectable change in
dielectric.
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The conductive type works best on
electrically conductive material
 e.g. metal or water-based material)
ULTRASONIC SENSOR
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Use ultrasonic technology
How does it works?
CONCEPTS OF ULTRASONIC
SENSOR
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Use an ultrasonic “ping” sent from sensor to
target
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Sensing area is a funnel shape area
Therefore, target must be located directly in front
of sensor
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When echo is returned, sensor detects
target by measuring time delay between
transmitted ping and returned echo
 sensor calculate distance between
sensor and target
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Do not work well on cloth, foam rubber
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since good absorber of sound waves
Works best on high density material
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where sound waves reflects best
DIFFUSE REFLECTIVE
Emitter
and receiver
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Emitter and receiver located in same
housing
Light emitted is received when the object
is present
Works well on glossy target but not
transparent
RETRO-REFLECTIVE
Emitter
and receiver
reflector
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Emitter and receiver located in same
housing.
Light emitted is received when the object
is absent.
Does not work well with glossy target.
Why?
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Because glossy target acts like a
reflector
THRU-BEAM
emitter
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receiver
Emitter and receiver is located in
different housing
Sense the object’s present when it
passes through between emitter and
receiver
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where it stops the light from hitting
receiver
FIBER OPTIC
Thru-beam
Reflector
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object
Use plastic and glass fibers to carry lights
Available in both thru beam and reflective
COLOR MARK
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A special type of diffuse reflective optical
sensor that can
 differentiate between colors
 some can detect contrast between
colors.
Typically used to check labels and sort
packages by color mark.
ENCODER
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Used for position feedback and some for
velocity feedback
Two main types
 Incremental
 absolute
CONDUCTOR
Definition:
 A medium that connects all the
components and allows current to
flow.
Examples:
 copper wire
 bread board
OUTPUT DEVICE
DEFINITION
 A component that will produce a
desired output.
 It is also referred to as a load.
COIL
Can represents various forms of
output including
 Motor
 Light
 Pump
 Counter
 Timer
 Relay
TIMER

most common symbol for displaying
timer function is in block diagram
 uses a box shape to display the
timer function
 Sometimes, timer is displayed in coil
format symbol
CHARACTERISTICS OF TIMER
Timers typically have one or two input
 Timer with one input has functions
as a timer enable input. When input
‘high’, the timer begins timing

A timer with 2 inputs has additional
functions which is used to reset the
timer accumulated time to zero
when the second input is ‘high’
 Every timer has a time base
 Typically; 1 sec, 0.1 sec and
0.01sec.
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HOW TIMERS ARE IDENTIFIED?
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Each timer will have number to identify it
There are two parameters for timer
 timer number
 Used to identify timer e.g. Timer 0,
Timer 2.
 Preset value
 Is the delay time set for the timer
TIMER’S PROGRAM
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There are still many similarities in the way
the timers are programmed
 even when PLC are different brand
Let say the time base of a timer is 0.1
second
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Therefore, if a programmer entered 50 for
the number of delay increments
What is the timer’s delay?
 the timer would have a 5-second delay.
 50 x 0.1 sec = 5 sec
TMR
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Has one input
Timer enabled if the input
logic is ON
Timer reset if the input
logic is OFF
Maximum value 9999
TMR
INPUT
TIMER0
T0
K40
TMRA
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Has two inputs
Timer starts timing when
ENABLE is ON
Timer stops when
ENABLE is OFF without
resetting the current
value to 0
ENABLE TMRA
TIMER2
T2
RESET
K50
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The timer resets when RESET is ON
The timer is enabled to start when RESET
is OFF
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What is it?
What is it characteristics?
How does it works?
Testing your understanding…..
Testing your imagination…..
COUNTER
used to capture and store number of
occurrence
CHARACTERISTICS
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set to some preset number value
 when this value of input pulses has been
received, it will operate its contacts
Let say the counter is set for 10 pulses,
then when 10 pulse impulses have been
received, the counter contacts will close
When there is a input transition for X0
from OFF to ON, counter starts
counting
 When the RESET is ON, the counter
resets to 0
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COUNTER PROGRAM
X0=sensor/ toggle switch
X1
INPUT
CNT
COUNTER0
CT0
RESET
K5
CT0
OUT1
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Counter starts counting when there is an
input transition
 X0 from OFF to ON
When the RESET is ON
 the counter resets to 0
MOTOR
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In PLC, motor can only be controlled
for
 power (ON/OFF)
 direction (CCW/CW)
 preset speed
TYPES OF MOTOR
DC motor type
wound field
permanent magnet
electronics commutation
dc motors
AC motor type
induction motors
synchronous motor