The USB (Universal Serial Bus) is a standard that defines the cables, connectors and used a bus to connect, communicate, computers, peripherals and electronic devices protocols Transmission Rates Low speed (USB 1.0). Transfer rate up to 1.5 Mbit/s (188 kB/s) used in keyboard, mouse ... transfer rate up to 12 Mbit/s (1.5 MB/s) High Speed ??(USB 2.0): Rate transferencia up to 480 Mbit/s (60 MB/s) SuperSpeed ??(USB 3.0) transfer rate up to 4.8 Gbit/s (600 MB/s) Connector Types 1 - USB type A (4 pin) 2. - USB type B (4 pin) 3 - Mini A (5-pin) 4 - Mini B (5-pin) 5 - Micro A (5-pin) 6 - Micro B (5-pin)

or horizontal. The micro USB with five pins, which pins identification (ID) Micro AB USB connectors special work. AB connectors with pin ID can allow the device to function as a connector A or B to standard USB technology. This gives the new smart phones and other devices the option to act as either a single storage device or as provi

The mini USB connectors are smaller than their standard counterparts and have USB fifth pin. The fifth pin is known as the pin ID and is typically not used in mini USB connectors. It was designed to allow later improved USB technology. The mini USB connectors have a cycle life of at least 5000 connections and disconnections, which accommodates the mobile nature of the devices that are designed to interact. The standard USB connectors are generally used with devices that are stationary and not disconnected often.

RS-232 (Recommended Standard 232, also known as EIA/TIA RS-232C) is an interface that designates a standard for the exchange of a series of binary data between a DTE (Data Terminal Equipment) and DCE (Data Communication Equipment , Data Communication Equipment), although there are others in which the RS-232 interface is also used. An equivalent definition published by the ITU is called V.24. The RS-232 is a connectorDB-25 type (25-pin), although it is normal to find the version of 9-pin (DE-9, or popularly also called DB-9), cheaper and even extended to certain types of peripherals (such as serial mouse PC).

USB 3.0 is the second major revision of the standard Universal Serial Bus (USB) connectivity for computing. USB 3.0 has transmission speeds of up to 5 Gbit/s, which is 10 times faster than USB 2.0 (480 Mbit/s). Connector Types 1 - USB type A plug 2 - 3 USB type A female - USB type B 4 - Micro USB B

Secure Digital (SD) is a memory card format for portable devices such as digital cameras, mobile phones, laptops and even game consoles (both desktop and laptop), among many others.

SDHC Speed Class 2 Class 2 2 MB/s
SDHC Speed Class 4 Class 4 4 MB/s
SDHC Speed Class 6 Class 6 6 MB/s
SDHC Speed Class 10 Class 10 10 MB/s
UHS Class 1 UHS Class 1 10 MB/s
UHS Class 3 UHS Class 3 30 MB/s

USB-C reversible USB version called USB cables USB Type C Type C or USB reversible. The important thing is this type of USB is that it has top and bottom. So you may save the blows that are given involuntarily to connect the connector upside down. It is also characterized in that when connected will make an audible "click". The USB-C or reversible USB cables can reach 10 Gbps and support USB 3.0, 3.1Use is estimated up to 10,000 applications and has some measures 8.4mm x 2.6mm is also compatible with USB 3.1 and USB indicate creators

IP65 Although it seems very complicated nomenclature IP standards is only one division in two digits, where each digit indicates that it is being served to meet these regulations. For the first digit would be: 0 No protection 1 element to be used for testing (sphere 50 mm in diameter) should not get to go completely. 2 element to be used for the test (area of ??12.5 mm diameter) should not get to go completely. 3 element to be used for testing (sphere 2.5 mm in diameter) must not come at all. 4 element to be used for the test (sphere of 1 mm in diameter) must not come at all. 5 ingress of dust can not be avoided, but it must not enter an amount that interferes with the proper functioning of equipment. 6 polvo should not come under any circumstances in the case of the second digit: Level Protection Against Expected Results Test Method 0 The water enters the equipment quickly. 1 The equipment is placed in their usual work. Should not enter the water when it is dropped from 200 mm height from the team for 10 minutes (at a rate of 3-5 mm³ per minute) 2, the equipment is put into lugar normal work. You should not enter the water when the leaves fall, for 10 minutes (at a rate of 3-5 mm³ per minute). This test should be performed four times at a rate of one for every 15 ° rotation both vertically and horizontally, starting each time the normal position. 3 The equipment is placed in their usual work. You should not enter the water spray at an angle up to 60 ° right and leftvertically to an average of 10 liters per minute and a pressure of 80-100kN/m for a time not less than 5 minutes. 4 The equipment is placed in their usual work. You should not enter the water thrown from any angle to an average of 10 liters per minute and a pressure of 80-100kN/m for a time not less than 5 minutes. 5 The equipment is placed in their usual work. Should not enter waterthrown jet (from any angle) by means of a nozzle 6.3 mm in diameter, at an average of 12.5 liters per minute and a pressure of 30 kN/m for a time not less than 3 minutes and a no closer than 3 meters. 6 The equipment is placed in their usual work. You should not enter water squirted (from any angle) through a nozzle diameter of 12.5 mm, an average of 100 liters per minute and a pressure of 100 kN/m² for at least three minutes at a distance of not less than 3 meters. 7 The object must endure without any filtration complete immersion in 1 meter for 30 minutes. 8 electrical/electronic equipment must withstand (without filtration) complete and continuous immersion depth and during the time specified by the manufacturer of the product with the agreement ofclient, but provided they are more severe than those specified for the value 7. For IP65 should meet the following standard conditions. Would hold cirscuntancias be dusty and prevent to enter under any cirscuntacia, and bear no powerful jets of water.

hen we talk about IP code (International Protection) we talk about an international standard (IEC 60529) which classifies the protection against external factors, solid or liquid, that has a component or electronic device; LED strips, controllers, meters, security cameras, etc.

This alpha-numerically standard has been designed to sort different levels of protection. Nomenclature starts with IP followed by two numeric values.

- Example IP68:

The first value ranges from 0 to 6 and indicates the protection against solid agents. In this case, strong protection against dust.

The second value is between 0 and 8 and indicates the protection against liquid agents. In this case the complete and prolonged immersion during the time specified by the manufacturer.

We could say that the larger the number is greater IP protection has a device.

In below table, we can see different IP protections levels available.

IPXX	First digit (IPxx)	Second digit (IPxx)
0	Unprotected.	Unprotected.
1	Protection against objects of> 50 mm diameter.	Protection against vertically dripping water.
2	Protection against objects of> 12.5 mm diameter.	Protection against inclined drip water up to 15°.
3	Protection against objects of> 2 mm in diameter.	Protection against water projected from any direction, up to 60°.
4	Protection against objects of> 1 mm in diameter.	Protection against splashing water any direction.
5	Ingress of dust is not entirely revented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment .	Protection against water jets.
6	Dust tight.	Protection against strong jets of water.
7		Protection against complete immersion up to 1 meter for 30 minutes.
8		Protection against complete and prolonged immersion.

Depending on the need for installation and type of base, trolley or chair, we can find various types of fixation. Among the most common we find:

A - Through hole: It has a hole in which a screw or stem is inserted. It is a very simple installation system. Ideal for wheels that should not support a lot of load.
B - Threaded stem: It has a threaded stem or nut, it is fixed to the surface with a nut. It is usually the most used fastening system.
C - Angular plate: They are usually less used fastening systems, they have lateral plates to fix on the base.
D - Plate: It has a rectangular or square plate on its surface, it includes 4 or more fastening holes to the base, it is one of the most common.
E - Smooth stem: The stem without thread is inserted into the female of the base, we can find it in the typical office chairs with wheels, TV furniture etc ...