LED strips for lighting: types, types, connection

Recommendation points

• Characteristics and performance of LED strips
• Colour
• Standard sizes
• Degree of protection
• Selection of LED strip
• Colour
• Luminous flux power
• Density of LEDs. Lighting uniformity
• Power supply selection
• Background lighting control
• Remote Control
• As part of Smart Home systems

LED strips appeared not so long ago – at the beginning of this century, however, they have already earned recognition as the most effective way to decorate rooms with light, economical lighting and backlighting. In the article we will look at the types of LED strips and how to connect them..

Characteristics and performance of LED strips

Structurally, the tapes are a strip of dielectric material, on the surface of which conductive tracks are fixed on both sides. The tape is divided into segments, where three or more LEDs are fixed. The main parameters of the tape:

1. Supply voltage: 6, 12, 24, 36, 110, 220 V.
2. Light output – 60-100 lm / W.
3. Length – 50-500 cm.

Colour

The simplest version of LEDs used in monochrome strips:

• red (wavelength 610-760 nm);
• orange (590-610 nm);
• yellow (570-590 nm);
• green (500-570 nm);
• blue (450-500 nm);
• violet (400-450 nm).

White CW LEDs are a phosphor coated UV diode. The principle of obtaining white color is similar to that of fluorescent lamps.

The full spectrum of luminescence is given by RGB strips. Each LED strip has crystals with red, blue and green glow. By adjusting the brightness of each light, you can get a full palette.

Standard sizes

The following are taken as the basic dimensions for SMD LEDs in the tapes:

• SMD 3528 (3.5×2.8 mm);
• SMD 5050 (5.0×5.0 mm).

In the designation of the standard size of the tapes, there are variants SMD 3528 and SMD 2835, which determines the orientation of the rectangular diode on the tape.

The density of the diodes on the tape is determined by the number of elements per running meter: 30, 60, 72, 120, 240. Together with the luminosity, the density determines the luminous flux from one meter of the tape in lumens, from 240 to 2640 lm / meter.

Degree of protection

Determined by standard IP classification:

1. IP20 – no protection.
2. Up to IP65 – tape and diodes are covered with a silicone layer. Protection against high humidity and dust.
3. IP 67 and more – one-piece silicone shell with maximum protection at the expense of the dimensions of the tape.

Selection of LED strip

It is necessary to evaluate the requirements for the lighting that will be implemented by LED strips, and based on this, select the best option.

The degree of protection is determined by the operating conditions. For concealed installation in an aluminum box in a residential area, protection IP20 (27) is suitable. With protection from moisture and partly from dust – IP65. For installation outside the building, including in a box – maximum protection IP67 and higher.

Colour

Determined based on personal preferences and lighting requirements, taking into account the following features:

1. Monochrome LEDs produce a narrow spectrum of color that, in the absence of other light sources, colors the illuminated space in its own color.
2. The white color of CW LEDs is the result of phosphor emission and can be warm, cool or neutral, with slightly different shades in relation to other types of lamps.
3. Tapes with identical characteristics from the same manufacturer, but of different batches, mostly differ in shade. This is important to consider when organizing lighting within the same room or building..

Luminous flux power

Lighting efficiency is characterized by the light output (lumens) emitted by the LEDs and the degree of illumination (lux). In this case, 1 lx = 1 lm / sq. m.

The key factors for selection are:

1. Distance to illuminated surface.
2. Required degree of illumination (lux).
3. Lighting fixture size, LED strip.

It should be based on the requirements for lighting in various types of premises. For living rooms, an illumination rate of 150 lux is prescribed, while 75 lux is sufficient for a wardrobe..

Knowing the distance from the tape installation site to the illuminated surface and the light scattering angle of the LEDs (120–150), you can determine the total luminous flux in lumens. Knowing the size of the lighting fixture, you can select the desired tape model.

Density of LEDs. Lighting uniformity

For contour lighting, for example, as part of a suspended ceiling or a closely spaced illuminated surface, the uniformity of the tape’s glow is important. Preference is given to tapes with maximum LED density.

In all other cases, the determining factor is the distance to the illuminated surface. Already after 10-15 cm, the border between light spots from diodes with a density of installation on a tape of 30 pcs / m is insignificant and only on uniformly painted surfaces.

Power supply selection

The key parameter for LED operation is the current strength and its direction. The LED strips already have current-limiting resistors (resistance), therefore, to connect the tapes, a DC power supply (PSU) is required, stabilized in voltage in strict accordance with the rating indicated on the tape.

It is not allowed to use parallel connection of two tapes of the same length or simple resistive voltage dividers. Only power supply of the appropriate rating. For parallel connection of LED strips, special amplifiers are used.

The second parameter of the PSU is power. Power determines the permissible length of the LED strip, which the power supply can power without any problems. The total power of the LED strip is ideally 10-15% less than the rated power of the selected unit.

Background lighting control

The controller adjusts the brightness and sets the operating modes of the LED strips. It is connected between the power supply unit and the LED strip and switches the supplied voltage, forming a high-frequency pulse power supply, of the order of kilohertz. The brightness of the diodes is set by the pause between pulses.

For RGB tapes, adjusting the brightness of each individual color is equivalent to changing the spectrum and brightness of the entire tape. A high-quality controller is capable of performing gamma correction, without which it is impossible to adjust the exact color reproduction.

If only brightness control is needed, without additional operating modes, then a dimmer is used.

When choosing, it is important to determine the following characteristics:

• maximum switched current, power;
• number of control channels;
• set of functions;
• way of setting the controller operating mode.

In addition, the controllers can support several control options:

1. Tactile (buttons and controls directly on the controller unit).
2. IR remote.
3. Wi-Fi, radio range.

Tactile control is suitable in the case of a single light source, for which a one-time adjustment at the time of installation is sufficient, or changes are rarely required.

Remote Control

To control LED lighting, special remote controls have been developed, on which you can clearly see which button you can select the appropriate color or adjust the glow spectrum, and also adjust the brightness or effect (strobe, light music, etc.).

In the case of Wi-Fi controller support, it is possible to control the lighting through an application on a smartphone, tablet or PC.

As part of Smart Home systems

To integrate into the Smart Home system, all controllers must be of the same type and have the same remote control protocol, for example, wireless Wi-Fi or a wired IP port.