KNOW WHY SECOND AND FOURTH ANGLE PROJECTION IS NOT USED IN ENGINEERING DRAWING !!

In Mechanical Engineering,drawings are made either in first angle projection or in third angle projection.We do not make drawings in second or fourth angle projection.We will discuss the reason behind doing so in this article.

Read this if you want to know difference between first angle and third angle projection.

DIFFERENCE BETWEEN FIRST ANGLE AND THIRD ANGLE PROJECTION EXPLAINED !!

Let us first understand the concept behind the angle projection system. Imagine you have Vertical Plane (VP) and Horizontal Plane (HP) (Perpendicular to each other),now we have 4 quadrants. For 1st angle projection system, we place object in 1st quadrant, for 2nd angle projection system, we place object in 2nd quadrant and so on.

In Second quadrant, Vertical plane (VP) lies in between object  and observer. Therefore front view of the object will lie on vertical plane whereas top view will lie on horizontal plane. As per rule of projection when horizontal plane is rotated 90 degree in clockwise direction, top and front view will overlap.

Overlapping projection views create confusion in the drawing. Therefore 2nd angle projection system is not used.

Similarly when object is placed in 4th quadrant both top and front view will overlap. Therefore fourth angle projection is also not used. 

To sum up, because of overlapping of front and top views 2nd and 4th angle projections are not used. First and third angle projection systems are recommended for orthographic projections.

KNOW WHY KTM IS FAST AND ROYAL ENFIELD IS SLOW !!

Royal Enfield despite of having 350 CC Engine is able to reach a top speed of 90-100 kmph whereas KTM Duke 390 is having 373 CC Engine is able to attain 160 to 165 kmph. Which simply means power of Duke 390 is way ahead of RE 350.

Now,coming to torque figures of both machine.Duke 390 produces 35 N⋅m @ 7250 rpm whereas RE 350 produces 28 Nm at 4000 rpm, which simply means maximum torque of RE 350 comes at very early stage whereas Duke 390 takes time to attain its maximum torque.In short we can say that RE 350 is a better pulling machine.

Now the question is that,what makes Duke 390 a fast machine despite of having almost same capacity engine.The technology used by Duke 390 is way ahead of RE 350. It uses DOHC,Liquid cooling and other latest technologies.Also Duke 390 is lighter than RE 350 but one thing that brings the drastic change is the construction of Engine.

Duke 390 uses oversquare engine 80.0mm bore and a 60.0mm stroke.The stroke is shorter than bore which helps in faster movement of engine as the distance to be covered in up and down motion is less.So,engine revs fast thus helps in attaining higher top speed.

On the other hand Royal Enfiled 350 uses undersquare engine 70 mm bore and 90 mm stroke.With longer stroke the engine becomes slow as distance to be covered is more.But this results in increased torque as,Torque=Force x Distance.

So,in this case engine revs slow which result in increased torque.

Click here to know more about oversquare,undersquare and square engine.

KNOW WHAT IS THE DIFFERENCE BETWEEN NET WEIGHT AND GROSS WEIGHT !

It is vital to understand weights when it comes to shipping goods. Weight is used to determine shipping costs regardless of whether the shipment is made by sea, air, rail, or road. The paperwork, quotes, and bill of lading will clearly indicate which weight the costs are based on for that shipping company.

Gross weight and net weight are two most commonly used terminologies used.We will understand the difference between gross weight and net weight in this article.

Net weight is the base weight of a product by itself. It is probably the term most people are familiar with, as they encounter it daily on food packaging. The net weight of a can beans is only the weight of the beans themselves and does not include the weight of the can.

The word gross means total. Thus, gross weight means total weight. The gross weight will include all aspects required for shipping. It includes the actual product, its packaging and any other packaging required to enable the shipping of the product.

There is one more terminology which is known as tare weight.Tare weight is the weight of the container in which a shipment travels. The weight of the container, full of your cargo, is what you will be charged to ship, or what you will pay to receive. Tare weight equals gross weight minus the net weight.

Summary:

1.Gross weight is the total weight of the shipment, including the raw products, its packaging, pallets, containers, and weight of transport vehicle.

2.Net weight refers to the weight of the raw product ordered. It does not include the weight of any container within which the product is held (e.g. a tin or box) or subsequent weight of pallets, larger containers, or the transport vehicle.

KNOW WHY FOG LIGHTS ARE USED !!

Front-facing fog lights and fog lamps are a type of automotive headlight that is designed to emit light in a bar-shaped beam. The beam is typically designed to have a sharp cutoff on top, and the actual lights are usually installed low and aimed toward the ground at a sharp angle.

WHY DO WE NEED THEM?

Fog is a regular occurrence in many parts of the world, especially near large bodies of water. When the conditions are right, tiny water droplets or ice crystals can float in the air, just over the surface of the ground. In addition to acting like a cloud and blocking your view, the tiny water droplets or ice crystals decrease visibility even further by reflecting light that hits them. This makes driving through fog with headlights, and especially high beams, a frustrating and dangerous experience.

Fog lights are a solution here, and take a different approach to all that water vapor hanging over the road. They work in multiple poor visibility conditions, including fog, mist, snow, and even blowing sand. In order to let you see the road through the fog, factory-equipped fog lights are placed as low as reasonably possible, usually in the lower bumper cover on most modern vehicles.

The purpose of the fog lamp is to show the driver the road edges, lane markings and the foreground abruptly appearing during road drive. When used with headlamps in extremely poor visibility, a driver can maneuver safely at slow speed in snow, fog or heavy rains.

DIFFERENCE BETWEEN HEADLIGHT AND FOG LIGHT

1.Driving lights are used in vehicle to provide clear view of forward of the vehicle and intended to supplement the high beam of a standard headlight system. While fog lights are used to reflect the fog, snow, or dust particles in the air are developed for use on dangerously thick conditions.

2.Driving lights produces white light while fog light produces both white and yellow light.

3.Driving lights are used to show clear vision to avoid any road obstacles during night time while fog lights are used in specific conditions like dust, train, fog or snow.

4.Driving lights are installed in every vehicle by default by the manufacturer while in some areas fog lights are also installed according to weather condition in specific region and in most areas it is optional.

WHEN TO USE FOG LIGHT:

You should only use fog lights in situations where there is poor visibility conditions caused by rain, fog, snow, or even an excessive amount of dust in the air.

In short, we can say that fog lamps should be only used in conditions where there is less visibility caused due to snow,fog,dust or rain.We should not use fog lamp in clear conditions as it may distract other drivers on road.

KNOW WHAT DOES "AM" AND "PM" MEAN IN TIME !!

Some countries, including the US, Canada, and Australia, use the 12-hour clock format including AM and PM. What do these abbreviations mean? We will discuss the meaning of AM and PM in this article.

AM stands for Ante Meridiam whereas PM stands for Post Meridiam. This is because the 24 hours of the day are divided into two periods- AM which means before midday and PM means after midday and each period comprises of 12 hours in number.

Hence, the term AM & PM is associated with the time-period: AM, is an abbreviation of the Latin phrase ante merīdiem meaning “before midday”; PM is an abbreviation of post merīdiem, meaning—“after midday.”

This rule gets a bit confusing when you take a look at 12PM and 12AM respectively. For example, 12AM - or ante meridiem - does not make logical sense when you look at the rule because it does not actually come after midnight. 

Therefore, it is always better to refer to 12PM as noon and 12AM as midnight respectively even if analog and digital clocks do label them as the former.

A 24-hour clock, sometimes referred to as military time, states the time according to the number of hours that have passed since midnight. Starting at midnight, hours are numbered from 0 to 24, removing the need for designations like am and pm. For example, at 23:00, 23 hours have passed since the beginning of the current day.

KNOW SCHOOL BUSES ARE ALWAYS PAINTED YELLOW !!

You must have noticed that every school bus has its school name written on it and is painted with yellow colour. Colors not only add to the aesthetic appeal of things, but they also make our lives much easier in many ways.In this article we will discuss the reason behind the yellow colour for School Bus.

Yellow (and the yellow family of colors) gets your attention faster than any other color. People notice yellow objects first.Even when you are looking straight ahead, you can see a yellow object that is not in front of you "in the corners of your eyes" much sooner than any other color even red. Scientists describe this as follows: "Lateral peripheral vision for detecting yellows is 1.24 times greater than for red."This means that as compared to the rest of the colours, yellow has 1.24 times more attraction and also more visibility. The yellow colour of the school bus is also known as the National School Bus chrome yellow.

If there’s fog or any kind of bad weather, drivers will still be able to see yellow cars and any moving vehicle fairly well.Not only are school buses yellow, but also many earth-moving, road-building and other outdoor machines are yellow because you could get hurt if you accidentally run into one of them. Many accidents occur in farms and outdoors because the victim saw the moving object too late. If it’s yellow, you have a strong warning!

This is why the school bus is painted with yellow so that the possibility of accidents on the highway will be less and children can reach their home safely.
Did you know that in the early 1930s, in the US, it was confirmed that there is more attraction in yellow colour than any other colours. That is why some signalling boards are painted with yellow colour.

KNOW WHY CAPTCHA IS USED !!

CAPTCHA is abbreviated as “Completely Automated Public Turing test to tell Computers and Humans Apart”. CAPTCHA is basically a program that can tell whether its user is a human or a computer. They are colorful images with distorted text at the bottom of Web registration forms in many web application development websites. It was coined in 2000 by professors and scientists from Carnegie Mellon University and IBM.

Which purposes does CAPTCHA serve?

CAPTCHA prevents spam in website comment sections and on blogs. Many spammers bombard comment sections with links to increase search engine rankings. The test makes sure only humans comment and users don’t have to sign in beforehand to leave a comment.

It offers protection from scrapers who want to copy the email addresses of users. Spammers would crawl the Internet for email addresses that are posted in clear text. By utilising CAPTCHA you can protect against these scrapers. People need to solve a CAPTCHA before an email address is shown.

Importance of CAPTCHA:

1. Using CAPTCHA you can protect your website or blogs from comment spams, as bloggers receive more than 100 spam comments each day. You can seek help of web development companies to implement this.

2. It is essential that mainly free services should be protected with a CAPTCHA in order to prevent abuse by automated programs.

3. CAPTCHA also avoids dictionary attacks. These are the type of attacks under which an automatically generated scripts or computer program tries random passwords on login forms in case on unsuccessful login.

4. It helps search engines to prevent crawling the spam contents that may be harmful for keeping database safe or sensitive data of being exploited.

KNOW THE DIFFERENCE BETWEEN PSLV AND GSLV !!

You might have heard about PSLV and GSLV rocket launch systems developed by the Indian Space Research Organization, or ISRO, to launch satellites into orbit.In this article we will understand the difference between PSLV and GSLV.

Let us understand this by an example:

Meet my 2 friends Polar and Geo.

I asked both of them to throw a 1.5 kg stone up in the air. Whose stone will go higher?
If everything is right, then normally Geo's stone will go higher than Polar's. Right?
Now if you ask Polar to throw a 0.5 kg stone, he may be able to achieve the same height as Geo's 1.5 kg stone. Whereas, Geo maybe able to throw three or four 1 kg stones to the same height as achieved by Polar's 1 kg stone.

This is the basic difference between GSLV (Geosynchronous Satellite Launch Vehicle) and PSLV (Polar Satellite Launch Vehicle).

Both PSLV (Polar Satellite Launch Vehicle) and GSLV (Geosynchronous Satellite Launch Vehicle) are the satellite-launch vehicles (rockets) developed by ISRO. The PSLV is the older of the two and the GSLV even inherits some of the technologies of the former in its design.

The main reason behind the advent of the GSLV is the capability to lift greater loads into space. While the PSLV can only lift slightly over a ton of payload to GTO (Geostationary Transfer Orbit), the GSLV is capable of lifting more than double that with a rated capacity of 2 to 2.5 tons. One of the main reasons why the GSLV has such an increased load is its utilization of a cryogenic rocket engine for its last stage. The cryogenic rocket engine provides more thrust than conventional liquid rocket engines but the fuel and oxidizer needs to be super cooled in order to keep them in a liquid state.

 

PSLV is a four-staged launch vehicle with first and third stage using solid rocket motors and second and fourth stages using liquid rocket engines. It also uses strap-on motors to augment the thrust provided by the first stage, and depending on the number of these strap-on boosters, the PSLV is classified into its various versions like core-alone version (PSLV-CA), PSLV-G or PSLV-XL variants.

The GSLV is designed mainly to deliver the communication-satellites to the highly elliptical (typically 250 x 36000 Km) Geosynchronous Transfer Orbit (GTO). The satellite in GTO is further raised to its final destination, viz., Geo-synchronous Earth orbit (GEO) of about 36000 Km altitude (and zero deg inclination on equatorial plane) by firing its in-built on-board engines.

 

 

When you look at their track records, it is easy to see that the PSLV is more reliable. With 18 launches, 16 of those were successes while only the first one was a total failure; the remaining one is called a partial failure as the satellite did not reach the intended altitude. The 7 launches of the GSLV have had worse results with 4 ending in failure and only two successes; it also has one partial failure launch.

 

In short:

 

1.The PSLV is older than the GSLV
2.The GSLV has a much greater load capacity than the PSLV
3.The GSLV use cryogenic fuel while the PSLV doesn’t
4.The GSLV has three stages while the PSLV has four stages
5.The GSLV has 4 liquid boosters while the PSLV has 6 solid boosters
6.The PSLV is more reliable than the GSLV

KNOW WHY TRACTORS HAVE VERTICAL EXHAUST !!

Tractors are extremely important agricultural vehicles. These machines are ubiquitous across the globe and range from rather small lawn tractors to giant monster worth hundreds of thousands of dollars. However, most of them have something in common – their exhaust pipes are pointing straight up in front of the driver’s cab. Meanwhile exhaust pipes of cars are located at the back, typically at bottom of the vehicle. Why is that? We will discuss the reason behind the vertical exhaust in this article.

 

Following are the reason why tractors have vertical exhaust :

1) Tractor is a off-road vehicle, usually used in every terrain including water dominated areas, where, there are chances of water to get in exhaust pipe and causing harm to the engine and exhaust system itself.

2) Mounting the exhaust pipe in the front has an added cost advantage – that’s where the engine is and less pipework is required this way. Less pipework – less maintenance as well.

3) Many chemicals are spread on crops or plants by driving tractor on the space between plants. If exhaust system is horizontal and below the driver them harmful and hot emissions can harm the crop.

4.)A normal tractor is constituted of two major parts – it can be split in two, which is occasionally done to repair transmission. Having an exhaust running from front to back would make such repairs hardly possible or very difficult.

Special note - Sometimes the end of exhaust pipe is curved, or has a hinged cover flap which the gas flow blows out of the way, to try to prevent foreign objects (including droppings from a bird perching, rain drops, ice on the exhaust pipe when the vehicle is not being used) getting inside the exhaust pipe.

Click "HERE" to download this article in PDF form.

KNOW WHY MOTORBIKES EXHAUST ARE GENERALLY PLACED ON RIGHT SIDE !!

You might have wondered why does almost every motorcycle have its exhaust placed on the right, and not the left?It is not a design constraint as such and you can have the silencer on the left as well. But there could be many reasons otherwise.We will discuss these reasons in this article.

Manufacturers have just stuck to the design that was implemented on the very first internal combustion-powered, single-cylinder motorcycles.The first motorbike without pedal was having exhaust on the right side. Since then manufacturers decided to mount the exhaust on the right side of the motorcycle.

Apart from this other reasons that are important to consider are as follows:


1. The exhaust fumes would be a little farther from the pedestrain walking sidewalks on the left.

2. Lot of women and old people sit sideways and it is much more safer to disembark them to the left. Silencer to the right helps with that.

3. Usually, there's a chain sprocket on the left side and having the silencer on the right balances the mass to some extent.

4. The way we learn to ride a bike, usually the left foot comes off the foot rest first when we are braking to a stop. Having the silencer to the right minimizes the risk of the foot coming in the proximity to the hot exhaust pipes.

But,it need not to be necessarily on right . Sports bikes have both sides , some have under the seat. But in general the exhaust is placed on the right side for above reasons.

KNOW WHY THESE GAPS ARE PRESENT IN THE STRIP OF MEDICAL TABLETS !!

Sometimes when you buy a strip of medicine (tablets), you notice of empty slots. Irrespective of the exact shape of the tablet, it can be round, rectangle, oval; every strip is packaged in this typical design-geometry.We will understand the reason behind the empty slots in this article.

Reason 1:

To keep up the standard size of the packing boxes, the company adds these extra spaces to avoid the extra cost.

Reason 2:

Since these tablets are small in size, but the minimum information required to be given on them is quite a lot, so the overall size of packaging is generally large so as to accommodate all relevant information.

Reason 3:

These extra empty spaces help to avoid breakage and spilling of medicines during transportation. This is one of the most important reasons why these empty spaces are there.

Reason 4:

This is a tricky one where our mind would get fooled by the packing. Extra spaciousness gives a feel that the tablet is worth the cost. But the actual fact is that it does not cost even an extra penny for the special packing!

Reason 5:

Empty space left is to increase the inertness of the tablet by pumping vacuum or inert gases inside the empty space. If air is present inside the empty space, then the tablets might get oxidized resulting in poor performance of the medicine.

Hope,this article might have helped you to understand the logic behiend those empty space.

ALL ABOUT PCB

Printed Circuit Boards are commonly known as PCB. There are electrical and electronic components are connected on the board. In the designing phase any pcb is connected via wires for testing purpose. It is very complex and very hard to test. The wire connections are not suitable for large applications like motherboard. Components are internally connected without wires in the PCB which decreases the overall complexity. PCBs can design as per the requirements. It is found in most of electronic devices like TV, Cell Phones, Computers, Camera etc. It is also used in communication devices, defence equipment etc. India Circuit is leading pcb manufacturing companies in india.

There are two types of Mounting processes are used Through-hole and Surface mounted.

First is through-hole PCB. There are holes made on the circuit to mount the leads of the components and it soldered on the other side of PCB. In the through-hole process the components have support from PCB for performance and this is widely used for mount the components on PCB. As there are holes are drilled in the PCB the manufacturing cost is increased. This is suitable for single-sided PCB but for double or multilayer it is not recommended.

The next method is surface mount. In this process there is small size components with small or no leads are used. In this process the components are directly mounted on the board and the holes are not required to mount. After mounting process, the solder paste is applied to hold components on the surface of PCB.

PCB construction is depending on the requirements. It is in single layer, double layer or multilayer.

Single Sided PCB

Double Sided PCB

Multilayer PCB

Rigid PCB

Flexible PCB

Rigid-flex PCB

Single Sided PCB 

First in the list is single-sided PCB. It is also called single layer PCB. It is widely used as it has simple design and easily manufactured. There is copper applied on the one side of PCB as the copper has better electric conductivity than other materials. The solder mask is applied to prevent the damage in the process of silkscreen coat for marking of components on the PCB. There is an electric component on the single side. The components are soldered on the other side of the PCB. Single sided PCBs are cost effective and it is best option for bulk manufacturing. Single sided PCBs are used in devices like printers, calculators etc.

Double Sided PCB

It is also known as double layer PCB. There is copper coat on the single side and in the double side the copper coating is on the both sides. The two layers are connected with hole made on the surface. The price of double side is low and are suitable to make complex circuit with compact size. Double sided PCBs are used in gaming motherboard, gaming pc, mobile phones, Inverter, Amplifies etc.

Multi-Layer PCB

There are more than two conductive layers in the multilayer PCB. There is glue is applied between layers to protect components from heat produced while performance. It is used for a complex circuit with compact size for best performance. This type of PCBs is used in satellite system, data servers etc.

Rigid PCB 

Rigid PCB is made from solid material which is very strong. It can be made in single layer, double layer and multilayer. The shape of PCB remains same after installation. It is not bent as per base. Rigid PCBs are long lasting. This PCBs is used in CPU, RAM and GPU. Single sided rigid PCBs are most used as it has simple design.

Flexible PCB

The material in the PCB makes it flexible. There is conductive plastic is used. Flexible PCBs are used where the rigid PCBs is not. It has very complex design and it is made in single sided, double sided and multilayer. This is used in LED, Solar Panel, Laptops etc.

Rigid-Flex PCB

This is a mixture of the Rigid and Flexible technique. Rigid-Flex contains number of rigid circuits are connect with flexible circuits. It is used in camera, cell phones etc.

We hope that this information is helpful to choose PCB according to your need.

India Circuit is leading PCB manufacturer in India.