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With the advent of LED lamps, it became possible to make the lighting design of apartments and houses more diverse. And when they came up with flexible strips with small LEDs attached to them, which can glow in different colors and even change color smoothly, only imagination is required: connecting an LED strip is a simple matter. Having done the operation once, you can easily repeat it.
Types and types
Before connecting the LED strip, it is worth understanding their types and markings. So you will not make a mistake with the choice of power supply and accurately calculate the required glow intensity, tape length and other parameters.
Colors and types of glow
You probably noticed that LED strips differ in the type of glow. They are:
- Monochrome. They are assembled from elements of the SMD type, give out a certain color. The marking indicates the initial letter of the English spelling of the color:
- LED-W-SMD – white (may be with a tint of blue or yellow, also called warm or cold light),
- LED-R-SMD – red,
- LED-B-SMD — blue,
- LED-G-SMD – green.
- Universal. Marked RGB – give different shades depending on the command from the control panel. Work in tandem with the controller and the control panel.
The most in demand in the illumination of interiors are ribbons made of plain – monochrome – crystals. The constant change of colors is too annoying, does not allow you to relax. This is illumination, not lighting. Therefore, universal tapes are used to create advertising, highlight cars – where it is necessary to attract attention. When decorating interiors, SMD tapes are mainly used.
Degree of protection
Since the scope of LED strips is extensive, the degree of protection is different. For dry rooms, ordinary open ones are produced – without a protective coating. There are waterproof ones – they can be used in wet rooms – in bathrooms for example. They are covered with a layer of varnish. There is another option – moisture resistant. They are sealed in a sealed housing and can be mounted directly in the water – in an aquarium, pond or pool. They can also be used for outdoor lighting.
For outdoor car styling, LED strips are most often used, placed in a transparent polymer tube. It protects not only from moisture ingress, but also from mechanical damage, but their cost is higher.
LED dimensions, brightness and density
Let’s deal with the sizes. If you take several strips, you can see that they are made of LEDs of different sizes. In addition, they are sometimes located tightly one next to the other, in some – at a fairly decent distance, and there are also strips with LEDs in two lines.
It is not difficult to distinguish the dimensions of the elements outwardly, but how to understand this by marking. Dimensions are shown in numbers after the letters indicating the type of LED. For example, LED-R-SMD3528 (red) and LED-RGB3528 (universal) are assembled from elements with dimensions of 3,5 * 2,8 mm, LED-G-SMD5050 (green) and LED-RGB5050 (universal) – 5,0 * 5.0 mm.
These are the two most common types, although there are larger ones – 56 * 30 mm, and there are also smaller ones – 20 * 20 mm.
The larger the crystal, the greater the intensity of light they give out. For monochrome crystals, the indicators are:
- 3,2 * 2,8 mm in size produces a luminous flux from 0,6 to 2,2 lm;
- size 5,0 * 5,0 mm – from 2 to 8 lm.
Universal LEDs with the same dimensions have a lower intensity: three small crystals of different colors are soldered in one case, therefore the RGB glow intensity is lower:
- 3,2 * 2,8 mm gives out 0,3 to 1,6 lm;
- size 5,0 * 5,0 mm – from 0,6 to 2,5 lm.
All values are for uncoated crystals. Any of them reduces the intensity of the glow and this must be taken into account when calculating the brightness of the glow.
Length calculation
Above we talked about each individual LED on the tape, and there are a lot of them on the tape and they are located with different densities, respectively, they can give out a stream of light of different intensity. The minimum number of crystals per meter is 30 pcs, the highest density in one row is 120 pcs/m, in two rows 240 pcs/m.
Depending on the number of crystals, both the total intensity of the glow and the electrical power consumption change. For the convenience of calculating the required lighting intensity and electrical parameters, the technical data are summarized in a table.
From this table, you can determine how long the backlight tape is needed. For example, you want to make a backlight in a room, a glow of medium intensity. Two 80W incandescent bulbs need to be replaced. It is necessary to organize a luminous flux of the order of 140 W (two lamps of 80 W each will never give 160 W).
If for these purposes we take an SMD3528 with a number of LEDs of 120 pcs / m, it will take about 5 meters of tape (we take it with a margin of 20%), an SMD5050 with an installation density of 60 pcs / m will need 4-4,5 meters.
In general, LED strip is sold by the meter. It comes from the factory in 5 m spools and a piece of this length is not always needed. Therefore, it is possible to cut off the required amount: along the applied dotted lines with the image of scissors. Strictly along these lines and you can cut.
If the scissors are not drawn, then there must be a dotted line. Also, the cut line can be determined by the presence of pads on both sides of the line.
Connecting the LED strip
Most LED strips run on 12V or 24V. If the line of crystals is one, the power supply is 12 V, if there are two – 24 V. Any DC source that produces this voltage is suitable: battery, power supply, battery, etc.
To connect the tape to a 220 V household network, a converter or adapter is required (also called blocks or power supplies, adapters).
Recently, tapes have appeared that can immediately be connected to a 220 V network. All of them are sealed in plastic tubes – 220 Volts is no longer a joke. They are also cut along the marked lines, connected using a special connector that is inserted into the conductors. A cord with a built-in rectifier is connected to the connector (this is a diode bridge and a capacitor).
This tape differs from the usual one in that in it small sections (20 pcs) with LEDs are connected not in series, but in parallel, also in such a way that the diodes are directed towards each other. Due to this, we obtain the required voltage of 220 volts or so. The alternating current is converted to direct current using a diode bridge, and the ripple is damped by a capacitor.
In principle, such a tape can be assembled from a regular one, but you will need to take care of the insulation: touching an element connected to a household network without an adapter is fraught with serious consequences.
How to connect multiple LED strips
Each of the tapes, depending on the modules used and the number of elements per meter, consumes a different amount of current. The average parameters are shown in the table. Knowing how long you want to mount the backlight, you can choose an adapter that will deliver the required current.
Sometimes the required tape length exceeds 5 meters – when it is necessary to illuminate the room around the perimeter. Even if the power supply can deliver the required current, two or more five-meter tapes cannot be connected in series. The maximum allowable length of one branch is those 5 meters that come in a reel. If you grow it by connecting the second one in series, a current will flow along the tracks of the first tape, many times higher than the calculated one. This will lead to a rapid failure of the elements. The track may even melt.
If the power of the power supply is such that several tapes can be connected to it, separate conductors are pulled to each of them: the connection scheme is parallel.
In this case, it is convenient to place the power supply in the middle, for example, in the corner, and from it there are two tapes on both sides. But it’s often cheaper to buy several smaller adapters than one more powerful one.
Connecting an RGB strip via a controller
The power supply is connected in series, then the controller. They are connected to each other with two wires. There are already 4 conductors coming out of the controller, which are routed to the corresponding contact pads of the RGB tape.
In the same way as in monochrome ribbons, in this case the maximum allowable length of one line is 5 meters. If a longer length is needed, then two bundles of wires of 4 pieces each depart from the controller, that is, they are connected in parallel. The length of the conductors can be different, but it is more rational that the power supply and the controller are in the middle, and two backlight branches go to the sides.
Connection methods
Connecting the LED strip to the power supply in series. Therefore, we pay attention to polarity: we connect “+” only to the same pole, and “-” to minus.
At the end of the tape, which comes on a reel, conductors are soldered. If the glow is monochrome, there are two conductors – “+” and “-“, for multi-color 4, – one common “positive” (+ V) and three colored ones (R – red, G – green, B – blue).
But a 5-meter piece is not always needed. shorter lengths are often required. Cut the tape along the marked lines.
In the photo you can see contact pads on both sides of the cut line. They are signed on each tape, so it’s quite difficult to get confused when connecting. To make it even easier, use conductors of different colors. So it will be clearer and you definitely will not get confused.
Connectors
You can connect the LED strip without soldering. There are special connectors for this. These are specially designed devices – plastic cases that provide proper contact. There are connectors:
- for connection to the conductor strip;
- connection of two tapes.
Different types of connectors
Everything is very simple: the cover is opened, a tape or conductors with bare ends are inserted. The lid closes. The connection is ready.
The method is very simple, but not very reliable. Contact is only provided by pressure, and if the cover is loosened a little, problems begin.
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If you have at least some soldering skills, it is better to use this method. To work, you will need a medium-power soldering iron, with a thin or sharpened tip. You need rosin or flux, as well as tin or solder.
We clean the ends of the conductors from the insulation, twist them into a tight bundle. We take a heated soldering iron, lay the conductor on the rosin, warm it up. We take a little solder on the tip of the soldering iron, we warm up the wires again. The veins should be tightened with tin – tinned. In this form, the conductors are easy to solder.
Similarly, it is desirable to lubricate the contact pads: dip the soldering iron in rosin, warm up the pad. Make sure that the tin does not leak out of the platforms. Take the prepared conductor, lay it on the platform, warm it up with a soldering iron. The tin should melt and tighten the conductor. Hold the conductor in place for 10-20 seconds (sometimes it is easier to hold it with thin-nosed pliers or tweezers – the conductor heats up), pull. He must hold on tight. We solder all the necessary conductors in the same way.
ON RGB strips with 4 wires, be careful not to connect the pads during soldering. The distance between the contacts is very small, the slightest streaks can ruin the whole thing. Act carefully.
Watch the process of soldering the diode tape in the video. You will need to repeat everything.