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.

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

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

When calculating the life of a battery it will be necessary to know the number of charge cycles that can be performed until the battery does not begin to lose its capacity.
Depending on the type of battery these charging cycles can vary, the most common being the mobile batteries, manufactured Li-Ion or Li-Po, which have a duration of between 300 and 500 charging cycles according to model and manufacturer.
Once thisE limit we will notice how the battery loses duration of operation, arriving to lose up to 25% of its capacity of load.
At this point it will be necessary to evaluate a battery change.
It should be noted that usage and charging habits can significantly affect battery life. For example, factors such as heat, charge the battery several times a day without it is almost exhausted, etc. Will be affectedits duration.
Therefore, to get the most out of the battery we must know when a full charge cycle is performed, and try to avoid misuse of charge, to increase its useful life.
A charging cycle is considered when the battery has been discharged or its 100% charge has been used.
The manufacturers advise that the charge is never made below the 58% battery, since the battery voltage would not fall so lowTo, so you could end up winning up to 4000 charge cycles.
Tips to increase the life of a battery.

• Avoid extreme heat or cold or very long applications of the device.
• Charge the battery as often as you can.
• Fully discharge the battery from time to time.
• Do not let the battery run out completely before charging.

Below is a table with theDifferent voltages (V), charge cycles (C) and battery percentage (B).

Within the detection systems we can find different types according to their operation, among them the most common:

1. Infrared sensors
2. Vibration sensors.
3. Photoelectric sensors.
4. Ultrasound sensors.
5. Acoustic sensors

Each type of sensor uses different detection methods and each one is recommended according to the situation.

1. Sensors by infraRrojos, are one of the most used types, thanks to its reliable operation and installation, since we can find this type of wired and wireless sensors.
   The infrared sensor has a phototransistor capable of detecting the infrared electromagnetic radiation emitted by a body, this type of radiation is not visible by the human eye. A change of radiation in its perimeter will activate the relay and proceed to send ato alarm signal.
   Within these, there are two models, passive infrared sensor, which only has a phototransistor and assets, which have an emitter and a receiver.
2. Vibration sensors are used mostly in security systems, such as window sensors. car alarms etc.
   Its operation is based on an accelerometer, through a piezoelectric sensor. This type of sensorDue to its construction material it allows to detect changes and pressure when emitting an electric charge.
3. Photoelectric sensors, these are the sensors that use photoelectric rays, normally a transmitter and a receiver are used, they are commonly used in automatic door systems, elevator doors, production chains, etc.
4. The ultrasonic sensors are those that emit an acoustic signalabout 30 kHz, a signal that is not appreciated by humans. This signal or wave propagates through space, walls, objects, doors, etc. once the signal has spread the sensor is activated and any change will trigger the sensor.
   These types of sensors are also used in devices that require measuring distances and detecting objects.
5. Acoustic sensors, are those that can detect the signal emitted by anyobject and are able to detect the pressures that the acoustic waves emit, such as the noise of the crystals when breaking a window.

Li-Ion or Lithium batteries are one of the most common batteries used today.
We can find this type of batteries in mobile phones, wireless headphones, SAIS, smart watches, cars etc.

Lithium is a very light metal capable of generating ions easily so it is ideal for the manufacture of batteries.

Unlike other types of batteries are a bit more expensive, but acThey are much smaller and lighter, capable of doubling the duration of a Ni-Cd.

Thanks to their composition can be manufactured in different ways, adapting to the device where they should be located, as well as its low memory effect makes them ideal for any type of device.

Summing up their positive points:

• Easy to find
• Many different sizes and shapes
• Small size