VAC would be the abbreviation of Volt Altern Current which would be translated Volts of alternating current. The difference between VDC is that its sinusoidal oscillation achieving a more efficient energy transmission.

The alternating current is the energy that we receive in our homes, it is generated in the power plants by means of alternators.

The intensity of this type of current varies with time, and changes direction 50 times throughsecond (50hz). The generated voltage changes in the form of sine wave so it is not constant.

In the image:

1. Current by pulsations.
2. Direct current (DC).
3. Alternating current (AC).
4. Variable current.

When we talk about RJ45 ("Registered Jack" 45) we refer to a telecommunications network interface for wired connection of voice and data equipment.

This connector has 8 pins or connections and may have a specific category depending on the data transfer speed and bandwidth (category 5e, 6, etc.)

The common application is their use in Ethernet network cables under TIA/EIA-568-B standard that defines the arrangement of pins (pinout), but can also be used for other applications.

- Direct pin diagram:

EIA-568A
Pin No.1: WHITE-GREEN
Pin No.2: GREEN
Pin No.3: WHITE-ORANGE
Pin No.4: BLUE
Pin No.5: WHITE-BLUE
Pin No.6: ORANGE
Pin No.7: WHITE-BROWN
Pin No.8: BROWN

EIA-568B
Pin No.1: WHITE-ORANGE
Pin No.2: ORANGE
Pin No.3: WHITE-GREEN
Pin No.4: BLUE
Pin No.5: WHITE-BLUE
Pin No.6: GREEN
Pin No.7: WHITE-BROWN
Pin No.8: BROWN

- Schematic of crossed pins:

The crossover cable has one end with EIA-568A scheme and the other one with EIA-568B.

Photovoltaic energy is produced by solar radiation using devices called photovoltaic cells. It is ideal for supplying all kinds of isolated houses, shelters, but also can be used to supply electricity on a large scale. We show the operating principle "In a semiconductor exposed to light, a photon of energy starts an electron, creating both a" gap "in the atom excitador. Normally, the electron quickly finds another hole to refill it, and the energy provided by the photon thus dissipates as heat. The principle of a photovoltaic cell is to force the electrons and holes to move towards the opposite side of the material rather than simply recombine in it: thus, there will be a potential difference and thus tension between the two sides of the material,as in a stack "The first ground application of a commercial installation of photovoltaic cell was developed in Japan in 1966. In the picture: 1 - PV Modules 2 - Regulation and Control 3 - Battery 4 - Inverter to power.... 220V

The RS232 connector is a connector type 9-pin connector is popularly called Series. It is a connector that was once widely used by various components of the PC, such as a mouse, keyboard ... but over time it has fallen into disuse and replaced by the USB connector trying to emulate the latest version number. It is currently used by robots, elevators, POS and industrial machinery.

The converters or inverters are used to convert the current of 12 or 24 volts (dc) battery, 220 volt current (AC). To choose an investor will take into account the rated power and the peak power of the inverter. The rated power is the power that can provide the investor in normal use and operation. While the peak power is that the investor may proporcionar for a short period of time. Investors modified wave (photo number 1) are used for virtually all types of devices even in some high-tech or inductive loads may not function properly because the wave is generated electronically. On the other hand, pure sine wave inverters (photo number 2) generate the same wavelength as that received at home. The wave modifiesIt gives but can be used with all types of devices always respecting the power that is able to provide the model we've purchased.

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).