One hertz is one cycle per second, meaning repeating cycle as an event. For example, hertz is applied physics measuring the number of times for a second wave (either acoustic or electromagnetic) is repeated or can be applied, among other uses, to ocean waves that reach the Beach vibrations per second or a solid. The quantity that measures the frequency hertz is called,in this regard, the inverse of the period. One hertz is an oscillation frequency of suffering a particle over a period of one second.

An uninterruptible power supply, UPS, also known as UPS (uninterruptible power supply English), is a device that, thanks to batteries or other energy storage elements, can provide power for a limited time and for a blackout all the devices connected. Other features that can be added to these teams is to improve the power qualityéctrica reaching loads, ups and downs filtering and eliminating voltage harmonics of the network in the case of using AC. There are different types of UPS UPS DC loads connected to the UPS require DC power, so they will transform the alternating current to direct current sales network and use it to power the load and store it in your batterys. So they do not require converters between the batteries and loads. UPS AC UPS obtained These outputs an AC signal, so they need an inverter to convert the direct signal from the batteries in an alternating signal. UPS standby (Standby Power Systems) This system has two main circuits: the power line, which only addsa stabilized and additional filtering of each team to normal feed, and the actual circuit UPS circuit whose core is called "inverter". It is called system "standby" or waiting, because the circuit of alternative power, the inverter is "offline" or inactive, waiting to become operational when it produces a failure in the power supply. It has a switching element that connectsand either circuit switched alternately. UPS line-interactive (in-line) This type of UPS regulates voltage variations by elevations or reductions in mains voltage. During these interventions, the UPS uses its battery to perform the voltage regulation. UPS online (online) In contrast, the UPS "online" (on-line), the battery and the inverter are permanently It is utiized, ensuring a maximum response in a timely manner before the event of network failure. In addition, they can also correct the frequency shifts as re-generate the ac wave permanently. Diagram UPS online In the picture (1) Rectifier The picture (2): battery in the picture (3): Inverter

We can define the paper formats according to their measures and these are defined in ISO standard 216 one, which in turn includes the standard DIN 476. This applies in most of the world. I there are plenty of measures for the role, but the most used are the Serie A and to a lesser extent Serie B.

In Serie A, the most widely used format is the A4 (210x297mm) or also called "sheet" used in most printers and fotocopiadoras.

Series B is defined for intermediate sizes Series A. For example, the B4 is the intermediate size between A3 and A4.

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).