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

Surface mount technology, better known by its acronym SMD (Surface Mount Device) is the method of construction of electronic devices most currently used. It is used for both active and passive components, and is based on the assembly thereof SMC (Surface Mount Component English) on the surface of the printed circuit. In the case of SMD LED technology is the differently constructedon the plate makes SMD LED and have a physical difference.

In the case of a terminal or other device with IP44 format would result. 4 - The element to be used for the test (sphere of 1 mm in diameter) must not come at all. 4 - Do 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.

VDC would be the abbreviation for Volt Direct Current which translated would volts direct current. The idea of ??this type is unidirectional current to the load. Direct current is normally produced by batteries, thermocouples, solar cells and a dynamo electric machine type. The direct current can flow in conductors such as wires, but may also flow through semiconductors, insulators ... In the image: 1 - current per pulse 2 - Direct Current (DC) 3 - Alternating Current (AC) 4 - Variable Current

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.

The SMD LED is an LED module that uses a surface mount technology to place a diode on the surface of a printed circuit and encapsulated on a semi-rigid resin. Typically used for lighting all types, since its opening angle can be 360° and LEDs, being very small, they can be distributed throughout the bulb. Ideal for decoration lighting in homes or places of transit dondand they will not be on continuously. It is also often used in automotive interior lighting. Each LED SMD chip is identified by a 4-digit number. This code identifies the size of the LED chip, the first two digits indicate the height and width the next two, in millimeters. For example, the dimensions of a LED 5050SMD are 5.0 x 5.0 mm. There is an exception, 3528SMD LED chip is also knownon how 1210SMD, with dimensions 3.5 x 2.8 mm.