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.

The degree Kelvin (K) is the unit used to classify the color temperature according to the scale created by William Thomsom from degrees Celsius. Lord Kelvin based on the table of William constructed a scale of temperatures to which its name is attributed to him.
A deeper explanation would introduce us into the world of physics, so in our sector knowing the relationship between Kelvins and kind of light will be sufficient.and.
This measurement factor is useful to know at a glance which tone or quality of light has a certain light source, for example, if we are going to buy a light bulb or a fluorescent we may be interested in knowing the kelvin it provides, as it will depend on This factor whether the light will be yellow or white.
The lower the kelvin value will be the light temperature, for example a 1600K bulb will have a temperatUra and color quality similar to the light of an exit or sunset. While a light bulb with 5000K will be more like daylight.
To better understand the relationship between kelvin and light temperature is attached the following table, where in a visual way it becomes easier to choose the type of bulb that best suits our needs.

A: It is equivalent to the temperature of a candle, it is aIn yellow light.

B: It resembles the color of dawn, it is similar to a tungsten bulb.

C: It is the tone of light of the old bulbs that were not led, filament bulb.

D: Similar to a study light.

E: Similar to mid-afternoon light about 20 °, similar to a fluorescent light warm.

F: Similar to mid-afternoon light at about 30 °.

G: Daylight, similar to a lightOf a flash.

H: Sunlight at noon.

I: Very sunny day and clear sky.

J: Partly cloudy day.

K: Cloudy day.

L: Wide shade clear day.

M: Very cloudy day.

N: Blue sky without sun.

O: Very clear day.

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.

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.

The lumen (symbol: lm) is the unit of the International System of Units to measure the luminous flux, a measure of the light power emitted by the source. The luminous flux of radiant flux difference that the former provides the variable sensitivity of the eye to different wavelengths of light and the latter involves all electromagnetic radiation emitted by the source according Wien law and Stefan-Boltzmann regardless of whether such radiation is visible or not. 1 lm = 1 cd. sr = 1 lx. m2