A switch is a device which is designed to interrupt the current flow in a circuit, in
other words, it can make or break an electrical circuit.
Every electrical and electronics application uses at least one switch to perform ON and
OFF operation of the device.
So, the switches are the part of a control system and without it, control operation cannot
be achieved.
A switch can perform two functions, namely fully ON, by closing its contacts or fully
OFF, by opening its contacts.
When the contacts of a switch are closed, the switch creates the closed path for current
flow and hence load consumes the power from source.
When the contacts of a switch are open, no power will be consumed by the load.
There are mainly two types of switches.
Mechanical Switch, and Electrical Switch.
Mechanical switches require physical or manual contact with switch for operation.
Electrical switches not require physical or manual contact, it has ability to perform
operation.
Electrical switches operate under the action of semiconductors.
Mechanical switches further classify into different types of switches based on number
of poles and throws.
There are five types.
1.
Single Pole Single Throw, (SPST).
2.
Single Pole Double Throw, (SPDT).
3.
Double Pole Single Throw, (DPST).
4.
Double Pole Double Throw, (DPDT).
5.
Intermediate Switch.
Mechanical Switches can also be categories on the basis of holding the current state.
There are two types.
Latch Switch, and Momentary Switch.
The latch switch holds its state whether ON or OFF until the new commands initiated this
switch.
And Momentary switch holds the state only when the specific command is presented only.
Latch Switch and Momentary Switch are 8 types.
1.
Push Button Switch.
2.
Limit Switch.
3.
Pressure Switch.
4.
Float Switch.
5.
Temperature Switch.
6.
Toggle Switch.
7.
Rotary Switch.
8.
Joystick Switch.
SPST (Single Pole Single Throw).
The SPST is a basic ON or OFF switch, that is used to connect or break the connection
between two terminals.
The power supply for the low circuit is given by this switch.
The application of SPST switch is light switch and it is also called as a toggle switch.
This type of switch has one input and one output.
SPDT (Single Pole Double Throw).
The SPDT switch is a three terminal switch, one terminal is used as input and remaining
two terminals are used as outputs.
It joins a mutual terminal to one or the other of two terminals.
The application of SPDT switch is mainly involved in a three-way circuit to turn ON or OFF a
light from two locations like from the top & bottom of a stairway.
DPST (Double Pole, Single Throw).
The DPST switch consists of two poles that means it includes two identical switches located
on side by side.
This switch is operated by one single toggle, which means that two discrete circuits are
controlled at a time through one push.
DPDT (Double Pole Double Throw).
This switch is equal to two SPDT switches, it means two separate circuits, connecting
two inputs of each circuit to one of two outputs.
The switch position controls the number of ways and from the two contacts each contact
can be routed.
Intermediate Switch.
An Intermediate Switch is where three points control the same circuit.
This is a very versatile switch and can be used for most lighting situations, but in
reality it is more expensive, so you would normally only use it when needed.
That is when you have three switches controlling one light, then the middle one needs to be
an intermediate.
Push Button Switch:
A push button switch to make switch allows electricity to flow between its two contacts
when held in.
When the button is released, the circuit is broken.
This type of switch is also known as a Normally Open Switch.
Limit Switch: Limit switch are used for controlling machinery
as part of a control system, as a safety interlocks, or to count objects passing a point.
A limit switch is an electromechanical device that consists of an actuator mechanically
linked to a set of contacts.
When an object comes into contact with the actuator, the device operates the contacts
to make or break an electrical connection.
Pressure Switch:
This type of switch consists of C-shape diaphragm.
According to pressure, this diaphragm is indicating pressure.
These switches are used to sense pressure of air, water or oil, in industrial application.
This switch operates, when pressure of system is increase or decrease from set point.
Float Switch: A float switch is a type of level sensor,
a device used to detect the level of liquid within a tank.
The switch may be used to control a pump, as an indicator, an alarm, or to control other
devices.
Temperature Switch:
This type of switches consists of temperature sensing devices like RTD and thermostat.
This switch operates according to the value of measured temperature.
Toggle Switch:
This type of switch is commonly used in household application to ON and OFF electrical appliances.
It has a lever by which we can move up or down to ON and OFF appliances.
Rotary Switch:
This type of switch is used to connect one line with one of the many lines.
Nob of multi-meter, channel selector, range selector metering device band selector in
communication devices are the examples of this type of switch.
This switch is same as single pole multi throw switch.
But the arrangement of this switch is different.
Float Switch: A float switch is a type of level sensor,
a device used to detect the level of liquid within a tank.
The switch may be used to control a pump, as an indicator, an alarm, or to control other
devices.
Joystick Switch: A joystick switch is actuated by a lever free
to move in more than one axis of motion.
One or more of several switch contact mechanisms are actuated depending on which way the lever
is pushed, and sometimes by how far it is pushed.
The circle-and-dot notation on the switch symbol represents the direction of joystick
lever motion required to actuate the contact.
Joystick hand switches are commonly used for crane and robot control.
Types of Electrical Switch.
Electrical switches are nothing but it is a semiconductor device.
These switches are more useful because of their low cost, small size and reliability.
Generally, this type of switches is used in integrated circuits (ICs), electrical motor
drives, HVAC application and also widely used as digital output of controller.
1.
Relay 2.
Bipolar Transistor 3.
Power Diode 4.
MOSFET 5.
IGBT 6.
SCR 7.
TRIAC
Relay: Relay works on the principle of electromechanical,
so this switch is also known as electromechanical switch.
When current pass through a coil, it will create a magnetic field around the coil.
Relay are available in wide range of voltage and current.
Bipolar Transistor: Bipolar junctions transistor has three terminals;
base, emitter and collector.
Transistors are work on three regions; cut-off, saturation and active region.
For switching purpose, active region is not used.
If sufficient amount of current is available at base terminal, transistor enter in to saturation
region and current will flow through collector-emitter path and transistor act as an ON switch.
If base current is not sufficient, circuit is open and current cannot flow through the
collector-emitter and transistor enters in to cut-off region.
In this region, transistor act as OFF switch.
Transistor are used as an amplifier in electronics application and it also used to make a gate
like AND, NOT in digital circuits and transistor is also used as a switching device in integrated
circuit.
Power Diode: Power diode have two terminals; anode and
cathode.
Diode is made up of p and n type semiconductor material and make PN-junction, which is known
as diode.
When diode is in forward bias current can flow through the circuit and in reverse bias
blocks current.
If anode is positive with respect to cathode, diode is in forward bias and act as a switch
ON.
Similarly, if cathode is positive with respect to anode, diode is in reverse bias and act
as a switch OFF.
Power diodes are used in power electronics application like, rectifier, voltage multiplier
circuit and voltage clamper circuit, etc.
MOSFET: MOSFET-Metal Oxide Semiconductor Field Effect
Transistor.
MOSFET has three terminals; gate, drain and source.
MOSFET is works on two basic forms; Depletion type and Enhancement type.
If gate-source voltage (VGS) is not sufficient, MOSFET works as depletion type and depletion
mode of MOSFET is similar to OFF switch.
If gate-source voltage (VGS) is sufficient, MOSFET works as enhancement type and enhancement
mode of MOSFTE is similar to ON switch.
Range of switching of MOSFET is tens of neon seconds to a few hundred microseconds.
MOSFET used in linear voltage regulator, chopper and audio frequency power amplifier, etc.
IGBT: IGBT- Insulated Gate Bipolar Transistor.
IGBT is a combination of BJT and MOSFET.
IGBT has a high input impedance and high switching speeds as well as low saturation voltage.
IGBT has three terminals; Gate, Emitter and Collector.
IGBT can control with the use of gate terminal.
It can be switched ON and OFF by triggering and disabling its gate terminal.
IGBT can block both positive and negative voltage same as GTO.
IGBT is used in inverter, traction motor control, induction heating and switched mode power
supplies.
SCR: Silicon Controlled Rectifier.
SCR has three terminals; Gate, Anode and Cathode.
Working of SCR is same as diode, but SCR start conduction when it is in forward bias and
positive clock pulse at the gate is also required.
In forward bias, if clock pulse of gate is zero, SCR turned off by forced commutation
and in reverse bias SCR is remains in OFF state same as diode.
SCRs are used in motor control, power regulators and lamp dimming.
TRIAC: TRIAC is same as two SCRs connected in inversely
parallel with gate connected.
TRIAC is bi-direction device.
TRIAC has three terminals; Main terminal 1 (MT), Main terminal 2 (MT2) and gate.
MT1 and MT2 terminals are connected with circuit which we want to control and gate is available
for triggering pulse by positive voltage or negative voltage.
When MT2 terminal is at positive voltage with respect to MT1 terminal and gate is also positive
triggered, then SCR-1 of TRIAC triggers.
When MT1 terminal is at positive voltage with respect to MT2 terminal and gate is also positive
triggered, then SCR-2 of TRIAC triggers.
TRIAC can used for both sources AC and DC but generally, TRIAC is used in AC application
like motor control, switching in lights etc.
Dear viewers, Thanks for watching the video, any question write in the comment box.
Don't forget to like and share.
More update please subscribes our channel Learning Engineering, and get notification
to press the bell icon.
For more infomation >> Breaking: President Trump Admin Took Millions From FEMA For ICE Detentions | Rachel Maddow | MSNBC - Duration: 9:36. 
For more infomation >> คิตตี้ ชิชา "แนนโน๊ะ" เจอเด็กใหม่ป้าตือ "แน่นเนอะ" ฮาแตกลั่นห้าง! - Duration: 7:00. 
For more infomation >> Big Rig Overturns, Killing Driver - Duration: 2:07. 
For more infomation >> 2 Found Hiding At Governor's Mansion After Nearby Shooting - Duration: 0:11. 
For more infomation >> Metro Atlanta also ramping up preparations for Hurricane Florence - Duration: 1:40. 
For more infomation >> After Obama Slams Trump In Speech, The President Slaps Back Hard With The Perfect Insult - Duration: 5:15. 
For more infomation >> 曾经称霸沦落成过街老鼠！纳吉信誉彻底破产。 - Duration: 11:51. 
For more infomation >> 1 Dead In Rancho Cordova Shooting - Duration: 0:30. 
For more infomation >> Trump Just Announced His New Border Wall Plan After Congress Didn't Listen To Him - Duration: 5:16. 
For more infomation >> Super Typhoon Mangkhut bears down on the Philippines and Hong Kong - Duration: 3:33. 
For more infomation >> 李健：你离开之后，我为你骄傲 - Duration: 11:05. 
For more infomation >> 好聲音導師豪宅，周杰倫、謝霆鋒奢華，李健沒買房原因感人 - Duration: 3:09. 
For more infomation >> 《中國新說唱》復活賽，艾熱全場MVP，與晉級三強爭奪冠軍 - Duration: 1:30. 
For more infomation >> 9/11/18 5:56 PM (1234 N Tyler Ct, Lafayette, OR 97127, USA) - Duration: 3:00. 
For more infomation >> La Californie veut être "neutre en carbone" d'ici 2045 - Duration: 5:59. 
For more infomation >> IFTTT - Duration: 0:54. 
For more infomation >> Comment est née l'idée du livre? - Duration: 1:10. 
For more infomation >> 🌝 5 ENSEIGNEMENTS DE VIE D'ECKHART TOLLE - Duration: 7:19. 
For more infomation >> Equipement de base pour avoir son cheval - Duration: 5:09. 
Không có nhận xét nào:
Đăng nhận xét