BELT DRIVES AND GEAR TRAINS

A belt drive is a system of pulleys connected by belts. Each belt connects a pair of pulleys.
1.To calculate the ratio of transmission between the first wheel and the last wheel of a belt drive, we must multiply the ratios of transmission of the first pair of wheels and the second pair of wheels:

⇒N4/N1=D1xD3/(D2xD4)⇐

2.We can use various systems to change the direction of rotation or the axis of rotation in a belt drive.



3.Worm drive: reduces the speed of a rotary system very effectively. A worm drive has two parts: a worm shaft and a worm gear.



ROTARY TRANSMISSION

Rotary transmission systems put two rotating elements into contact. These mechanisms have two purposes:
-Transferring rotary force from an input location to another location.
-Changing the rotary speed by using rotating elements of different sizes.

1.Changes in speed

-Increasing speed system:

                                       Driver pulley

                                                          ↓   

-Constant speed system:



-Decreasing speed system:

                                                                                                 Driver pulley

                                                                                                          ↓



2.Speed ratios

The relationship betweenthe speeds of the two wheels is inversly proportional to their sizes.

N2/N1=D1/D2

LINEAR TRANSMISSION OF MOTION: PULLEYS AND COMPOUND PULLEY SYSTEMS

A pulley is a wheel that rotates around an axis and has a groove. We can divide pulleys into two basic types:

-Fixed pulley: The forces are equal because the rope moves the same distance on both sides. ⟹F=R⟸

-Movable pulley: We need half the force to lift the same weight as with a fixed pulley.

⟹F=R/2⟸



A compound pulley system is a combination of fixed and movable pulleys.We can combine the pulleys in various ways:

-Vertical and horizontal system:

⟹F=R/2xn⟸

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⇣                                                                                                                        ⇣

LINEAR TRANSMISSION OF MOTION: LEVERS

A lever is a rigid bar that turns around a point called a fulcrum. Law of the lever :

Fxd = Rxr

Classes of levers:

-Class 1 levers: increase the force that we apply and the distance that the end of the levers move.



-Class 2 levers: increase the force that we apply.



-Class 3 levers: increase the distance that the end of the lever moves.



WHAT IS A MECHANISM

Mechanisms make work easier because they transmit and transform forcé and motion.
All mechanisms require an input force. They transmit motion and force to receptors, that finally perform the work. This is the output force and motion.

Input of force and motion ⇒ Mechanism ⇒ Output force and motion

CREATING INFORMATION

-WEB PAGES: The first step is to plan the desing and content of everything that will appear. The steps that you must follow are:
1. Register a domain: you must choose a name that is not already being used.
2. Sign up with a host server: domain registration services may also provide hosting , and web page design companies often include both registration and hosting.
3. Design and create your web page: this will can make your web page more attractive and user-friendly: title, colour combinations, a balanced layout, hyperlinks, visual impact, comments from users and page order.
4. Upload your page to the server: you can use FTP programs to upload your web page to the server. these programs manage the transfer of web page files from your computer´s hard drive to a server.
5. Update your page regularly: remember that if the content is always up to date, people will continue visiting your web page.

-BLOGS: They were originallyused as online diaries for people to share their personal experiences. Blogs have other characteristics wich made them interesting: the same blog can be shared by various bloggers working together as a team; blogs can include hyperlinks to potos, audio recordings or videos; we can use blogs to make daily reports about a projectand receive helpful feedback from other people; and businesses can use blogs to improve their costumer service.


-WIKIS: Is a collection of web pages that visitors can edit, modify or expand. The content grows quickly with the contributions of the people working on it.

VERTICAL SOCIAL NETWORKS

The users of vertical social networks form communities who have similar reasons for using the application. These reasons may include:
-Sharing profesional information: LinkedIn.
-Sharing general information: FriendFeed.
-Sharing photos: Instagram.
-Sharing videos: YouTube.
-Live streaming: Skype.
-There are many other services related to other topics.

HORIZONTAL SOCIAL NETWORKS

The users of horizontal social networks form communities who have diverse interests and a wide variety of reasons for using the application. The most popular horizontal networks are:
-Facebook: This application allows groups of "friends" to publish both public and private messages with text , links , news , potos and videos. They may also share information about how they are doing at any particular moment.




-Twitter: In this social network , users publish short text messages with no more than 140 characters. The relationship between users are not always bidirectional.




-Google+: Allows users to create "circles" of friends in order to share information. They can share photos and form public or private communities.

WORKING IN THE CLOUD

Some Internet services let us create , save and modify documents online. The most popular cloud-based services are Google , Drive , Dropbox and Onedrive.
The two main advantages of these services are:
-Access to our files from any location or device with an Internet connection.
-The ability to share our files easily with other people.

SOCIAL BOOKMARKING

Social bookmarking is an Internet tool that lets us organise , use and share information more efficiently. All of our content is stored in the cloud. some of the most popular social bookmarking applications are:


-Delicious is a service that lets us save our favourites web pages along with a description and a list of key words for easier classification. We can share information with other people and see the content that they have bookmarking.


-Diigo defines itself as a "multi-tool for for knowledge management". Among other functions , it lets us bookmark the pages that we visit and create a digital library in the cloud.


-Evernote provides a convenient workspace where we can collect information by capturing articles and images from the Internet. Then we can add notes and share information with other people .

NEWS FEEDS

Rich Site Summary (RSS) is a subscription service that provides users with frequent updates from media websites , blogs and other sources of information .
RSS news feeds are convenient and time-saving . People can subscribe in two ways:
-By clicking on a "subscribe" icon.
-Through a news aggregator program.

WEB PAGES

A web page is a collection of documents that ca include text , audio , video , images and hypertext links to other web pages . A browser is a program that locates a web page by its address and lets users access the content.
A search engine is a web page with a database of information about other web pages and their content.

WEB 1.0, WEB 2.0 AND WEB 3.0

-WEB 1.0: Information on the Internet was only for reading . It was a network of documents and people could not interact with the content . In addition , the information online was not updated very frequently .


-WEB 2.0: Information became bidirectional . Users could not only receive information , but also create and share it .


-WEB 3.0: New technologies allowed the integration of data and the web so that programs could "understand" and work with the information that they received

INFORMATION ABOUT THE BLOG

IN THIS BLOG I GO TO TEACH YOU THE CONTENT THAT I STUDY IN MY TECHNOLOGY LESSONS.

I GO TO UPDATE WHEN I CAN AND WHEN I HAVE THE KNOWLEDGE.