Friday, 13 November 2015

Difference between Speed and Torque...?????










Speed is the measure of how far something travels in a given period of time. It is also known as the rate of change in position.



For a Motor , Speed is measured in revolutions per minute (RPM ).





Torque is force exerted as an object rotates.To turn , a motor shaft requires certain amount of torque.


If some load is added to the shaft , more torque is required to turn it.



Two motors of different sizes may run at the same speed.


A Shaded pole motor ( example ;- window fan ) exerts very little torque.Its common speed is 1200 to 1800 RPM.




Whereas a large Industrial motor (example ;- factory conveyor belt ) may exert a very high torque in order to start a heavy load , and yet it turns at a similar speed.





The same is true for engines. An Eight cylinder car engine can run at 3600 RPM and exert a great amount of torque.




A small generator will run at 3600 RPM , but not exert nearly as much torque as the car.



;)







Wednesday, 11 November 2015

How Laser Printer Works..????






Laser Printer Working :-




A Laser Printer is a bit mysterious , how can a laser beam , a highly focused beam of light write letters and draw pictures on paper.




Many people use laser printers in their day-to-day lives , but most probably never think about the technology that turns those bits of digital data into a legible images and text.




The Primary principle at work in a laser printer is static electricity , the same energy that makes clothes in the dryer stick together,




Static electricity is simply an electrical charge that build up on an insulated object , such as a balloon or your body.




Since oppositely charged atoms are attracted to each other , objects with opposite static electricity fields cling together.




A Laser Printer uses this phenomenon as a sort of temporary glue.The core component of this system is photoreceptor , typically a revolving drum or cylinder.This drum assembly is made out of highly photo conductive material that is discharged by light photons.




Initially, the drum is given a total positive charge by the charge corona wire - a wire with an electrcal current running through it.




As the drum revolves , the printer shines a tiny laser beam across the surface to discharge certain points.



In this way the laser draws the letters and images to be printed as a pattern of electrical charges - an electrical image.




After the pattern is set , the printer coats the drum with positively charged toner - a fine black powder.




Since it has a positive charge , the toner clings to the negative discharged areas of the drum , but not to the positively charged background.




This is something like writing on a soda can with glue and then rolling it over some flour.




The flour only sticks to the glue coated part of the can , so you end up with a message written in powder.




With the powder pattern affixed , the drum rolls over a sheet of paper which is moving along a belt below.




Before the paper rolls under the drum , it is given a negative charge by the transfer corona wire.




This charge is stronger than the negative charge of the electrostatic image , so the paper can pull this toner powder away.




Since it is moving at the same speed as the drum , the paper picks up the image pattern exactly.




To keep the paper from clinging to the drum , it is discharged by the detac corona wire immediately  , after picking up the toner.




;)




Friday, 6 November 2015






 # FOURDRINIER ( PAPER MAKING MACHINE )



A Fourdrinier is a huge papermaking machine which takes input as waste paper Or wood fibres and produces output as a finished paper roll.
Many modern paper making machines are based on the principles of the Fourdrinier Machine.

This Machine was invented in the early 1800's and is accredited to Henry Fourdrinier , a London based Stationer , although it was actually invented by a Frenchmen called Louise - Nicholas Robert.

The Fourdrinier Machine consists of four main sections :-

(1.) Forming section Or Wet end
(2.) Wet Press section
(3.) Dryer section
(4.) Calender section

Although , so many other small things are also present in between these sections like :- Size press , M.G roll , Coaters , Pope reel e.t.c.

(1.) Forming Section :-

Because woodpulp fibres Or waste paper fibres ( in case of recycling ) has a strong tendency to clump, it needs to start off with a very high percentage of water content, allowing the pulp to have an even distribution, the slurry (or furnish) held in the Headbox contains around 99% water.

The furnish travels down the Slice onto the revolving Wire ( woven plastic fabric meshed conveyor belt ) at the Breast Roller point of contact.

As the furnish travels along the wire, so water is removed and the pulp fibres are aligned in a uniform direction.

It is this process that allows perfect distribution of the pulp fibre across the sheet as well as giving the paper strength and stability by aligning the fibres. Suction rollers hold the furnish to the meshed wire and help remove the water content.

By the time the paper or web has reached the Wet Press Section , at that point the consistency has gone from 1% pulp content to 25%.

(2.) Wet Press Section

The Wet Press Section carries the wet web between a series of rollers under high pressure to squeeze more water from the paper, much like a mangle.

The Felts ( woven plastic fabric conveyor belts ) support the web and also aid water removal by absorption. As the web enters the third section the paper web consistency can be as high as 40%.

(3.) Dryer Section

In this section , Steam heated rollers cause further water removal by making direct contact with paper through evaporation as well as further use of felts , bringing the water level down to as low as 30%.

(4.) Calender Section

The final Calendar Section allows the web to pass between Calendar Rollers that smooth out the surface of the paper.
If the paper has a coating then the degree of calendering will change the characteristics of the coating.

For example, gloss artpapers have a higher degree of calendering than a velvet sheet.

The main purpose of Calender section is to make the paper smooth , brighter and glossy.

Now one thing that is not shown in the diagram and is the first thing that strikes anyone who visits a paper mill for the first time is the absolute vastness of Fourdrinier machines.

Each roller in the Dryer Section can have a diameter of several metres, the width of the reel of paper can vary from 5 to 10 metres long and weigh several tonnes.

The Machine from the Top Box to the Dry End could cover the distance of a football field.

The machines are so large that operatives have to use three wheel scooters to move from one end to the other.

What is Size Press in Paper Making Machines..????




Size Press is one of the major part of the Paper Making machine.It generally consists of two rolls of specific diameter.


The main purpose of Size Press is to apply a solution of starch or other material onto the surface of the dry paper coming from the dryers and then it is again dried. 


Some Paper machines contain a unit for the  application of certain liquid media to the Web surface like :- Size Press , Top Coater , Bottom Coater , Pre Top Coater.


The Process of applying Starch solution , a Sizing agent Or a mixture of both by means of Size Press is known as Sizing.


The main reason for paper sizing is to increase the strength and printability of paper products by the chemicals ( mostly starch ) applied acting as binding agent.


Starch is the most agent used , but in recent years a combination of Cationic Starch and synthetic copolymers has been increasingly used to improve the effects of surface sizing.


Cationic starch increases strength of the the paper because it binds to the anionic paper fibres.


In Size Press coating Or a thin film of chemicals is applied on the paper web by means of rolls.

Tuesday, 21 April 2015

CONTINUOUSLY VARIABLE TRANSMISSION ( CVT )..??????






Some people say that you can't teach an old dog new tricks.



But the Continuously variable Transmission (CVT ) , which Leonardo da vinci conceptualized more than 500 years ago is now replacing planetary automatic transmissions in some automobiles , is one old dog that has definitely learned a few new tricks.


SO WHAT DOES THAT CVT MEAN    ???????



CVT is a power transmission system from engine to the driveshaaft with the help of which our vehicles move forward.


Unlike traditional automatic transmissions , CVTs don't have a gearbox with a set number of gears , which means they don't have interlocking toothed wheels.



The most common type of CVT operates on an ingenius pulley system that allows an infinite variability between highest and lowest gears with no discrete steps or shifts.



If you are wondering why the word "gear" still appears in the explanation , remember that a gear refers to a ratio of engine shaft speed to the drive shaft speed.



Although CVTs change this ratio without using a set of gears. 



Today several car manufacturers , including General motors , Audi , Honda and Nissan , are designing their drivetrains around CVTs.


Some vehicles which are using this system are :-  

1.)   Aircrafts ( for electrical power generation

   2.)   Honda Activa                                                                            3.)   Snow vehicles 

4.)    Golf carts   e.t.c.




;)

Friday, 10 April 2015

WHAT IS A BEARING...??????







Have you ever wondered that how things like inline skate wheels and electronic motors spin so smoothly and quitely ?




The answer can be found in a little machine element called bearing.





The bearing makes many of the machines working possible which we use everyday.




So, A bearing is simply a machine which is used to support the shaft transmitting power and to reduce frictional  losses between machine elements.





As we all know if we have to transmit power to a long distance then we need a long shaft.



In that case we use a bearing to support that shaft to prevent its bending due to its own weight and also to reduce frictional losses.






;)

Sunday, 5 April 2015

SADA BIKE or A SPOKELESS FOLD UP BICYCLE







A bicycle is great for transportation needs , but it takes up a lot of room inside a home.



In smaller living spaces , bike storage can be a tricky thing to figure out.



As a solution to this problem , Italian designer Gianluca Sada , of Sada bike , has come up with an amazing solution for easy bicycle storage developing a spokeless bicycle that folds up like an umbrella.


;)




Sunday, 29 March 2015

WHAT IS A TUBELESS TYRE....????????????



Tubeless tyres are those which do not require a separate inner tube unlike tubed tyres.

Advantages of tubeless tyres are :_

1.)  In case of puncture , the air leakage is very          slower. As the air can leak only through the            point of puncture, it gives sufficient time to the        driver to control the vehicle.

2.)  Better fuel efficiency , because of the light             weight due to the absence of the tube.

3.)  No tube related problems.

4.)  Less chance of damage in case of flat running ,        because no air instant loss.

:)

SPRUNG and UNSPRUNG WEIGHT....WHAT IS IT ....????????





SPRUNG WEIGHT  :--  Sprung weight is a term                                     used to describe the parts of a car that are supported by the front and rear suspension springs.

For e.g :--  Vehicle's frame , body , engine , driver ,                all liquids and the power train above the wheels.

These are quite heavy assemblies.


UNSPRUNG WEIGHT  :--   The Unsprung weight                                            includes wheels , tyres , brake assemblies , rear axle assembly and other structural members which are not supported by the suspension springs.

We can also say that all parts outboard from suspension springs.



The difference between two is also clear from the image.


:)

Sunday, 1 March 2015

TYPES OF PETROL


LEADED AND UNLEADED PETROL 

(1.)  LEADED PETROL   :--  In this type ,                                                Petrol is treated

 with a lead compound i.e Tetraethyl Lead ( C8 H20 Pb) to reduce knocking ( problem due to unburn fuel ) problems in the vehicle.

But combustion of leaded petrol releases Lead into the air where it causes lead poisoning.


That is why Lead in petrol is banned in U.S.




(2.)  UNLEADED PETROL  :--  In this type of                                             petrol leaded compounds are not used.

      
This type of petrol is mostly used.

;)

FUNCTION OF LUBRICATION AN INTERNAL COMBUSTION ( I.C ) ENGINE



# NEED FOR LUBRICATION.




In an I.C engine moving parts rub against 


each other causing frictional force.


DUE TO FRICTIONAL FORCE HEAT IS 


GENERATED AND THE ENGINE PARTS 


WEAR EASILY.


POWER IS ALSO LOST DUE TO FRICTION.





TO REDUCE THE POWER LOST AND 


WEAR AND TEAR OF THE MOVING 


PARTS A SUBSTANCE CALLED 


LUBRICANT IS INTRODUCED BETWEEN 


THE RUBBING PARTS OF THE ENGINE.








# FUNCTIONS OF LUBRICATION.

1.) IT REDUCES FRICTION BETWEEN MOVING PARTS.

2.) IT REDUCES WEAR AND TEAR OF MOVING PARTS.
3.) IT MINIMIZES POWER LOSSES DUE TO FRICTION.
4.) WHILE LUBRICATING IT ALSO CARRIES SOME HEAT FROM THE
MOVING PARTS AND DELIVERS IT TO THE SURROUNDINGS
THROUGH THE BOTTOM OF THE ENGINE (CRANK CASE).
5.) IT REDUCES NOISE CREATED BY MOVING PARTS.
6.) IT ACTS AS A CLEANING AGENT.
7.) PROTECT ENGINE PARTS FROM RUSTING.


;)

How Hydro Power Plant Works...?



Basically it is clear from the image that how Hydropower Plant works.

But,I am going to explain it...

Hydropower Plants capture the energy of falling water to generate electricity. A Turbine converts the kinetic energy of falling water to mechanical energy.

The turbine is further connected with generator, so the generator converts the mechanical energy from the turbine into electrical energy.

This generated electricity is then transferred to the transformers and from these transformers it gets transferred to the main power lines.

Hydroplants range in size from " Micro-Hydros " that power only a few homes to giant dams like Hoover Dam that provide electricity to millions of people.

;)

HYBRID VEHICLE.....


A ' Hybrid vehicle ' is a vehicle that uses two or more power sources to move the vehicle.

In practice , that means a hybrid vehicle will have a traditional internal-combustion engine and a fuel tank , as well as one or more electric motors and a battery pack.

;)

Saturday, 28 February 2015

How does a Photocopying Machine Works...??????

Photocopying machines are fairly complicated devices,but the basic principle is pretty simple.

At the heart of the process there is static electricity , a metal drum , a system of lenses and dark powder.


The machine's function depends on the fact that opposite electrical charges attract each other.


COPY A LETTER  :---  Let's follow the process of copying a letter :--


When you put the letter on the glass plate and push the start button, a metal drum below the glass is given a negative electrical charge.


A bright light shines on the original image and a system of lenses projects that image onto the drum.


Where the light strikes the surface of the metal drum the electrical charge disappears, but the dark parts of the image , that is the letters on the page, keep their charge.


THINK POSITIVE AND NEGATIVE  :--  At this point positively charged particles of black powder are deposited on the drum with its negatively charged letters.


Since opposite charges attract each other, the powder sticks to the plate where the letters are,but not to the rest of the drum, which has no charge.


Then a negatively charged piece of paper is pressed against the positively charged powder which is transferred to the paper.


Heat is momentarily applied to fuse the powder to the paper and out comes a warm copy of your letter.


So,its the interaction of positively and negatively charged parts in the photocopy machine  that allows the image to be copied from one piece of paper to other.


;)

Sunday, 22 February 2015

Heat Transfer v/s Thermodynamics


Heat Transfer tells us :--

(1.) how ( with what modes ) heat is transferred
(2.) at what rate heat is transferred                     
(3.) temperature distribution inside the body      

Thermodynamics tells us :--

(1.) how much heat is transferred 
(2.) how much work is done         
(3.) final state of the system          ;)

Friday, 20 February 2015

AMAZING GOOGLE TRICKS............ :)


I have some amazing google tricks guys. i m  definitely sure that you should also find these interesting ...


(1.)  GOOGLE GRAVITY  :--   Just type GOOGLE GRAVITY in your google search box but don't enter ... see the suggestions.
 from these suggestions click on i 'm feeling lucky  which appears on the right side of the  

''Google gravity'' suggestion..



  • google gravity
  • google gravity underwater
  • google gravity tricks


  • like this...

    after this u will find that every option on your screen will fall down  like :--  search box.., Google e.t.c.
    at this time you are able to search things by finding the search box..but the things you are going to search will also fall down.

    (2.)  BARREL ROLL  :--   Just type " do a barrel roll " in your search box and enter. 

    (3) ZERG RUSH : --.  Type    "ZERG RUSH " in your search box press enter and wait for few seconds .

    (4.)  GOOGLE SPHERE  :-- Type GOOGLE SPHERE in your search box and do the same process as you have done in GOOGLE GRAVITY...

    i hope you will enjoy guys... :)

    Wednesday, 18 February 2015

    PROXIMITY SENSOR....$$$$$$$


    A Proximity Sensor is sensor able to detect the presence of nearby objects without any physical contact.
    A Proximity sensor often emits electromagnetic radiation , and looks for changes in the field or return signal.

    Operating Principle of Proximity Sensor :-

    A high frequency magnetic field is generated by coil in the oscillation circuit. 

    When a target approaches the magnetic field , an induction current flows in the target due to electromagnetic induction.

    As the target approaches the sensor , the induction current flow increases , which causes the load on the oscillation circuit to increase.

    Then oscillation attenuates or stops. 

    The sensor detects this change in oscillation status with the amplitude detecting circuit , and outputs a detection signal.