DOL STARTER

A DOL( direct on line) starter is a type of motor starter which is basically simple and attaches the motor terminals directly to the power supply. It normally governs the performance of an electric motor by applying the full line voltage to the motor terminals. 

WATER BOTTLING PLANT



http://www.youtube.com/watch?v=vpXSHUbD0ig

Q:Why Human body feel Electric shock ? n in an Electric train during running , We didnt feel any Shock ? why?

A:Unfortunately our body is a pretty good conductor of electricity, The golden rule is Current takes the lowest resistant path if you have insulation to our feet as the circuit is not complete (wearing rubber footwear which doing some repairs is advisable as our footwear is a high resistance path not much current flows through our body).The electric train is well insulated from its electrical system.

About Diode

An Ideal Diode should have Zero resistance in the forward bias and an infinitely large resistance in reverse bias.

OSCILLOSCOPE

Oscilloscope is widely used for measurement of time-varying signals. Any time you have a signal that varies with time - slowly or quickly - you can use an oscilloscope to measure it - to look at it, and to find any unexpected features in it

.

STEPPER MOTOR

Stepper motor is the electrical machine which act upon input pulse applied to it. it is one type of synchronous motor which runs in steps in either direction instead of running in complete cycle.so, in automation parts it is used.

What is Flip Flop:

A bistable multivibrator. A circuit which has two output states and is switched from one to the other by means of an external signal (trigger).

How to Design Heat sink for IGBT?

Any fined aluminum extrusion with a flat smooth surface can be used then your IGBT is mounted on it with a layer of silicon grease in-between, but remember the mounting surface is also your collector, if your heat sink is going to touch other metal parts it is beter to electrically insulate the IGBT with a silicon insulator strip and insulating sleeves for the mounting screws, then the heat sink can be mounted on a box that is fitted with a cooling fan with the fins inside the box, else it can be mounted open with the fins in a vertical position for natural airflow over the fins

Lenz's Law

Fleming Right Hand Rule:

Fleming Right Hand Rule:
As per Faraday’s law of electromagnetic induction, whenever a conductor moves inside a magnetic field, there will be an induced current in it. If this conductor is forcefully moved inside the magnetic field, there will be a relation between the direction of applied force, magnetic field and the electric current. This relation among these three directions, is determined by by Fleming Right Hand Rule

Operational Amplifier

An operational amplifier (op-amp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op-amp produces an output potential (relative to circuit ground) that is typically hundreds of thousands of times larger than the potential difference between its input terminals.

A proportional-integral-derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller calculates an "error" value as the difference between a measured process variable and a desired setpoint. The controller attempts to minimize the error by adjusting the process control inputs.

DC Motor

A DC motor is a mechanically commutated electric moto powered from direct current (DC). The stator is stationary in space by definition and therefore the current in the rotor is switched by the commutator to also be stationary in space. This is how the relative angle between the stator and rotor magnetic flux is maintained near 90 degrees, which generates the maximum torque.

Induction Motor

An induction or asynchronous motor is an AC motor in which current is induced in the rotor winding by the magnetic field of the stator winding, by electromagnetic induction.

INFRARED SENSOR:

An infrared sensor is an electronic device that emits and/or detects infrared radiation in order to sense some aspect of its surroundings. Infrared sensors can measure the heat of an object, as well as detect motion.

SOLENOID VALVE:

The media controlled by the solenoid valve enters the valve through the inlet port (Part 2 in the illustration above). The media must flow through the orifice (9) before continuing into the outlet port (3). The orifice is closed and opened by the plunger (7).
The valve pictured above is a normally-closed solenoid valve. Normally-closed valves use a spring (8) which presses the plunger tip against the opening of the orifice. The sealing material at the tip of the plunger keeps the media from entering the orifice, until the plunger is lifted up by an electromagnetic field created by the coil.

1. Valve Body
4. Coil / Solenoid
7. Plunger
2. Inlet Port
5. Coil Windings
8. Spring
3. Outlet Port
6. Lead Wires
9. Orifice

R.O. (Reverse Osmosis) system:

Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane. This membrane-technology is not properly a filtration method. In RO, an applied pressure is used to overcome osmotic pressure, a colligative property, that is driven by chemical potential, a thermodynamic parameter. RO can remove many types of molecules and ions from solutions and is used in both industrial processes and in producing potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. To be "selective," this membrane should not allow large molecules or ions through the pores (holes), but should allow smaller components of the solution (such as the solvent) to pass freely.

LEVEL SENSOR:

Level sensors detect the level of substances that flow, including liquids, slurries, granular materials, and powders. Fluids and fluidized solids flow to become essentially level in their containers (or other physical boundaries) because of gravity whereas most bulk solids pile at an angle of repose to a peak. The substance to be measured can be inside a container or can be in its natural form (e.g., a river or a lake).

What is IGBT ?

The insulated-gate bipolar transistor or IGBT is a three-terminal power semiconductor device primarily used as an electronic switch and in newer devices is noted for combining high efficiency and fast switching. It switches electric power in many modern appliances: Variable-Frequency Drives (VFDs), electric cars, trains, variable speed refrigerators, air-conditioners.

How a clamp meter works:

How a clamp meter works:


In electrical and electronic engineering, a current clamp or current probe is an electrical device having two jaws which open to allow clamping around an electrical conductor. This allows properties of the electric current in the conductor to be measured, without having to make physical contact with it, or to disconnect it for insertion through the probe. Current clamps are usually used to read the magnitude of asinusoidal current (as invariably used in alternating current (AC) power distribution systems), but in conjunction with more advanced instrumentation the phase and waveform are available. Very high alternating currents (1000 A and more) are easily read with an appropriate meter; direct currents, and very low AC currents (milliamperes) are more difficult to measure.

CURRENT TRANSFORMER (CT)

A CURRENT TRANSFORMER (CT) is used for measurement of alternating electric currents. Current transformers, together with voltage transformers (VT) (potential transformers (PT)), are known as instrument transformers. When current in a circuit is too high to directly apply to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments. A current transformer also isolates the measuring instruments from what may be very high voltage in the monitored circuit. Current transformers are commonly used in metering and protective relays in the electrical power industry.

What is Opto coupler?

In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal.

Diode

A diode is an electronic device which allows current to pass through in 
one direction but not in the other. It is commonly used in another device call a bridge rectifier which is used to convert alternating current into direct current.

Pressure Transmitter

A pressure transmitter is a pressure sensor, typically for gases or liquids. This pressure sensing device has current output. It can also be defined as an analogue device that produces a charge in voltage or current when the internal pressure changes state.

Thyristor

A thyristor is a four-layer semiconductor that is often used for handling large amounts of power. While a thyristor can be turned on or off, it can also regulate power using something called phase angle control. This allows the amount of power output to be controlled by adjusting the angle of the current input. An example of this is the a dimmer switch for a light.

What is Solenoid

A coil of wire that acts as an electromagnet when electric current is passed through it, often used to control the motion of metal objects, such as the switch of a relay.

SERVO VOLTAGE STABILIZERS

Servo voltage stabilizers save the life of costlier appliances, CNC machines, electrical equipment, medical equipment, motors lab equipment etc. through connecting AC voltage which is not stabilized, and dips at one point of time and at other point of time rises to very high value. The principle of operating Servo Stabilizer involves comparing the output voltage with built in stable reference voltage source. The solid state control circuit operates the motor whenever the output voltage falls or rises beyond the preset voltage.

DCS ( Distributed Control System):

A distributed control system (DCS) refers to a control system usually of a manufacturing system process or any kind of dynamic system, in which the controller elements are not central in location (like the brain) but are distributed throughout the system with each component sub-system controlled by one or more controllers.

Human Machine Interface

Human-machine interface is the part of the machine that handles the Human-machine interaction. Membrane Switches, Rubber Keypads and Touchscreens are examples of that part of the Human Machine Interface which we can see and touch.

WHAT IS SERVO DRIVE

A servo drive receives a command signal from a control system, amplifies the signal, and transmits electric current to a servo motor in order to produce motion proportional to the command signal. Typically the command signal represents a desired velocity, but can also represent a desired torque or position. A sensor attached to the servo motor reports the motor's actual status back to the servo drive. The servo drive then compares the actual motor status with the commanded motor status. It then alters the voltage frequency or pulse width to the motor so as to correct for any deviation from the commanded status.

ANALOG INPUT/OUTPUT CARD

There are two types of communication signals PLC is

handling either to field instruments ( O/p) or from field 
instruments ( i/p). This digital signals are used as 
control on / off operation in o/p card and read present
status in the form of On or OFF. 

Digital signals are in the form of binary logic either
Present ( High may be 5 V / 24 V) or Low ( o V)
In analogue form of signal It can be 0 to 10 V in descrite
values ( o to 100%) or 4 to 20 MA) These analogue signal
received from Load cells, Transducers or from position
control devices.

Variable-Frequency Drive

A variable-frequency drive (VFD) is a type of adjustable-speed drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.

A transformer is a static electrical device that transfers energy by inductive coupling between its winding circuits.

 A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a 

varying magnetic flux through the secondary winding. This varying magnetic flux induces a varying electromotive 

force (emf) or voltage in the secondary winding.

Transformers range in size from thumbnail-sized used in microphones to units weighing hundreds of tons 

interconnecting the power grid. A wide range of transformer designs are used in electronic and electric power 

applications

Isolated-gate bipolar transistor(IGBT)

The Isolated-gate bipolar transistor or IGBT is a three-terminal power semiconductor device primarily used as an electronic switch and in newer devices is noted for combining high efficiency and fast switching. It switches electric power in many modern appliances: Variable-Frequency Drives (VFDs), electric cars, trains, variable speed refrigerators, air-conditioners and even stereo systems with switching amplifiers.

Electric Power Transmission

Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to electrical substations located near demand centers.
Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long-distance transmission. Power is usually transmitted through overhead power lines. Underground power transmission has a significantly higher cost and greater operational limitations but is sometimes used in urban areas or sensitive locations.

RELAY

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used

Modbus

MODBUS



Modbus is a serial communications protocol originally published by Modicon (now Schneider Electric) in 1979 for use with its programmable logic controllers (PLCs). The main reasons for the use of Modbus in the industrial environment are:
developed with industrial applications in mind
openly published and royalty-free
easy to deploy and maintain
moves raw bits or words without placing many restrictions on vendors

Modbus allows for communication between many (approximately 240) devices connected to the same network, for example a system that measures temperature and humidity and communicates the results to a computer. Modbus is often used to connect a supervisory computer with a remote terminal unit (RTU) in supervisory control and data acquisition (SCADA) systems.

Mobile or Portable Substation

The mobile substation or portable substation is fully equipped with different power system equipments, and must be able to be shipped from one place to another with fully assembled mode.

The World Smallest Relay Ladder Programmable Controller

Motors

Most motors in control applications are just regular DC motors. A few are AC, and a few are true servomotors.

A true servo motor is optimized for high speed control systems. Specifically, you want fast linear response. To get this, they are typically somewhat high in cost, relatively low armature inertia, high torque (to give good acceleration). Often have marginal cooling (i.e. not rated for high duty cycle).

Electromagnetic Induction

Electromagnetic induction is the production of a potential difference (voltage)

]across a conductor when it is exposed to a varying magnetic field.

Michael Faraday is generally credited with the discovery of induction in 1831


Faraday's law of induction is a basic law of electromagnetism predicting how a 

magnetic field will interact with an 

electric circuit to produce an electromotive force (EMF). It is the fundamental 

operating principle of transformers, 

inductors, and many types of electrical motors, generators and solenoids.

Photodiode

A photodiode is a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation.[1] The common, traditional solar cell used to generate electric solar power is a large area photodiode.

How a proximity sensor works?

How a proximity sensor works :

A proximity sensor is a type of sensor which detects the presence of nearby objects called target without any physical contact. There are different types of proximity sensors such as inductive proximitysensor, capacitive proximity sensor, ultrasonic proximity sensor, photoelectric proximity sensor. Depending on the type of technology used proximity sensor emits an electromagnetic or electrostatic field, or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal when target comes closer to the face of sensor.

There are different kinds of proximity sensors. They are

Capacitive proximity sensor
Inductive proximity sensor
Photoelectric proximity sensor
Ultrasonic proximity sensor

The advantages of the non contact proximity sensors are:

No physical contact required with the target to be detected, therefore, no moving parts so no friction and wear out.
Fast switching characteristics
Unlimited number of switching cycles since there is no mechanical contact
Can work in harsh conditions
Any type of target material can be detected.
A proximity sensor is used in many applications such as in mobile phones and for level sensing. In Iphone proximity sensor is used to deactivate the touch screen when the phone comes near to the face.