Design Mechatronics Systems
MTE 305
Level 300
Lecture (8)
Presented By
Dr. Shaimaa Ahmed
Chapter(7)
Industrial Classic Control
2
Fundamental Components of Industrial Control
Systems
1.Relay
•Electrically operated switches that
open and close circuits.
•Uses an electromagnetic coil to open
or close the circuit.
•Current energizes the coil, creating a
magnetic field.
•The magnetic field pulls the switch's
arm away or pushes it down to close the
switch.
3
Fundamental Components of Industrial Control
Systems
2. Contactor
•Widely used for switching circuits.
•Forms a subcategory of relays.
•Suitable for higher power applications.
•Allows low voltages and currents to
power cycle higher voltage/current
circuits.
4
Fundamental Components of Industrial Control
Systems
3. Overload relay
•Wired in series with motor.
•Current flows to motor during
operation.
•Overload relay trips when
excess current is present.
•Opens circuit between motor
and power source.
5
Fundamental Components of Industrial Control
Systems
4. Motor protection circuit breaker
• Protects individual electric motor.
• Prevents overload, input current
fluctuations.
• Prevents unscheduled circuit interruptions.
6
Fundamental Components of Industrial Control
Systems
5. Fuses
•Essential for protecting
circuits from significant
current increases.
•Types: Fast-acting fuses for
quick overcurrent response in
electronics.
•High rupture capacity fuses
handle higher fault currents.
•Commonly used in power
and control circuits for safety
and equipment protection.
7
Fundamental Components of Industrial Control
Systems
6. Switches
•Controls current flow
in circuits.
•Opens or closes
circuits.
•Comes in ON, OFF,
or ON/OFF
configurations.
•Can be push-buttons,
selector switches, or
toggle switches.
8
Wiring Diagram
9
Wiring Diagram
10
POWER CIRCUITS & CONTROL CIRCUITS
POWER CIRCUITS: A power circuit is a type of circuit that carries power to
electrical loads. Power circuits often carry high voltages and consist of incoming
main power, a motor starter, and the motor. Power circuits are usually shown in a
diagram with heavy lines since they are the heavy conductors or wires carrying
motor or load current.
CONTROL CIRCUITS: A control circuit is a type of circuit that uses control
devices to determine when loads are energized or de-energized by controlling
current flow. Control circuits usually carry lower voltages than power circuits.
Control circuits are usually associated with pilot or control of the power switching
equipment, such as the coil circuit in a magnetic starter. These wires are shown
using lighter lines in the diagram.
11
Power Circuit for a Single-Speed Motor
Three-phase Power Supply (L1, L2, L3):
The power source must provide a voltage matching the
operating voltage of the motor.
•Three Fuses (Q1):
These fuses must withstand the high current required during
the motor's startup.
They are of the "fuse-switch" type and can also function as
the main switch to disconnect power from the circuit.
•Main Contacts of the Contactor (KM1):
These contact points must be able to handle the current
drawn by the motor.
•Thermal Overload Relays (F2):
These components are designed to carry the motor's current
and protect it from overload conditions.
•Motor Terminals (U, V, W):
The three terminals of the motor that connect to the three-
phase power supply.
12
Design a 24V DC control circuit for motor operation where the motor runs only
when the push button is pressed and stops immediately upon release.
• F1: Fuse
To protect the control circuit from short
circuits.
• Q1: N.O. contact of motor protection
Used to disconnect the control circuit when
the motor overload protection trips.
• S1: N.O. Push Button
Used to turn ON the motor.
• KM1: Contactor
Used to operate the motor.
13
Design a control circuit for a motor with Start/Stop functionality and include
indicator lamps to display the motor's status in terms of operation, stoppage, or
overload tripping.
14
Design a control and power circuit for a 3-phase motor with Start/Stop
functionality and include indicator lamps to display the motor's status in terms of
operation, stoppage, or overload tripping.
15
Design a power circuit for a three-phase motor that enables bidirectional
rotation.
16
Timers
17
Design a circuit where pressing the Start Push Button (P.B) starts both motors,
and pressing the Stop Push Button (P.B) stops Motor 1 (M1) immediately while
allowing Motor 2 (M2) to run for a specified time delay t.
18
Design a circuit to operate 2 motors, such that when the Start button is
pressed, both motors (M1 and M2) start. After a time delay of T1, M1 stops. After
a time delay of T2 following the stop of M1, M2 stops.
19
CADe SIMU
20
