The COB Led (chip on board) is a plate (A) with a concentration of LEDs in the form of matrix (B) covered with a special silicone.
This type of led due to its design and installation allow to dissipate in a more efficient way the heat generated by the lighting.
It must be taken into account that the heat is generated in the opposite direction to the light and a low dissipation will cause the led to work in less optimal conditions.thus, its useful life.

Thanks to this design the Led COB is designed to work for long hours.
Its beam of light is multidirectional, so it is a type of diffuse light without dazzling at a point, achieving up to 160 º opening light and have a superior performance to the type of LED SMD.

Its manufacturing cost is 20% lower than an SMD led and its technology offers a reproducible indexchromatic ion (CRI) much higher, getting a better appreciation of colors.

In short, the COB LEDs can produce more lumens using much less energy than the rest of the LED technologies.

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.

A DIN Rail is a metal rail of with standard size of 35 mm wide. (A)

It's commonly used on installation and assembly of electrical devices or controllers for home or business use.
Besides the typical DIN rail 35 mm x 7.5 mm, can also be found in other measures as:

- Mini DIN Rail, size 15 mm x 5.5 mm (B)
- DIN Rail, size 35 mm x 15 mm (C)
- G section, size 32 mm x 15 mm x 8mm (D)

These rails are designed for installations with a method of simple, fast and configurable fixing. Ideal for installation in electrical distribution points, distribution of telephone wiring, alarms, digital electric programmers, keystone adapter, attenuators and any other compatible device.

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

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.