New Year is the brightest and kindest holiday for the majority of the population of our country. People dress up Christmas trees and expect something bright and good. However, a festive mood cannot be created without the right illumination, which is traditionally garlands. They are made from incandescent bulbs, neon. However, LED products are considered to be the most economical and safe. Such garlands can be assembled even with your own hands. It is only necessary to observe some installation rules. Today's article will talk about the parallel connection of LEDs, how it is performed and when it is applied.
What types of switching LED elements exist
There are two main types of connection - serial and parallel. Each of them is applied in its own field. For example, if we are talking about New Year's electric garlands, then a series connection is often performed here. It allows you to use incandescent or neon bulbs designed for low voltage. For example, 4.5 V bulbs connected in series in the amount of 50 pcs. they can easily withstand voltage of 220 V. With this switching, the plus of one radiator is connected to the minus of the other, and so on throughout the entire circuit.
But such a rule does not apply to LED Christmas lights. The fact is that for the correct operation of LED components, the alternating current of the home network is not suitable. For normal operation, they need a stabilizing power supply. This means that the voltage should be low anyway. It is much easier to stabilize 12V than 220 V.
The nuances of connecting LEDs
As you know, there is a serial and parallel connection of LEDs. In this case, the question arises, why is one chosen for garlands with incandescent lamps and neon, and another for LED elements? Here it is the characteristics of the emitters. Each LED has its own voltage drop indicator. Provided that the stabilizing power supply is not too powerful, a large number of LED elements cannot be connected to it in series. It is for this reason that parallel switching is used in garlands.
Someone may say that it is enough to take a power supply more powerful, because at the same time it will be easier to control the voltage at the LEDs (it will be equal on each of them). But here is the problem. Even if you take a regular garland of LEDs for 50 LED elements, the adapter will be so large that you can’t hide it under a small Christmas tree.
Helpful information! If the voltage drop across the chips is higher than the power supply rating, such an adapter may not be able to withstand long-term operation.
Parallel and serial connection of LED components: video explanations
Some information on LED connections can be found in the next video. It clearly demonstrates what it is.
What is required for switching LED elements
Parallel connection of LEDs implies the use of limiting resistors and emitters, as close as possible to each other in characteristics. If the selection of LED elements in terms of indicators is simple, then the resistance necessary for their correct operation must still be calculated. It is worthwhile to figure out which formulas are used for this.
When the LEDs are connected in parallel, the calculation of resistance should begin by calculating its nominal resistance, measured in ohms. For this, it is necessary to divide the voltage difference between the power source and the LED element itself by the product of the LED current by a factor of 0.75. The data on LED elements is taken from the technical documentation.
For normal operation of the circuit, it will be necessary to calculate one more parameter. With a parallel connection of LEDs, the calculation of the resistor in power is also extremely important. It is made as follows. It is necessary to divide the square of the voltage difference between the power supply and the LED element by the resistance obtained from previous calculations.
How to make a DIY LED garland
Having calculated the resistors and soldered them to the cathodes of the LED elements, you should determine the voltage of the power supply that will be used. The most convenient option is the use of a controller from an old Chinese garland. This device will not only act as a stabilizer, but also save you from solving the question of how to make the LEDs blink when connected in parallel.
Next, you need to stretch the wire, mark the future locations of the emitters with a marker. According to the marks, small pieces of insulation are removed - 15-20 mm each. This work should be done carefully so as not to damage the wire core. Having covered the cleaned places, you can solder the LEDs to them. The resulting spike must be insulated with a part of the LED element, resulting in increased joint strength. For these purposes, it is better to use a transparent adhesive tape, which will not impede the passage of light.
Switching the resulting garland with a controller
If you open the case of the Chinese device, on the side opposite to the supply wire, on the edge, you can see 2 or 3 output contacts. If there are 2 of them, it is immediately clear how to solder, if 3, then the extreme ones are used, and the central one remains empty.
With such work, you should not use a powerful soldering iron with a thick sting - there is a danger of spoiling the equipment. If there is no other way out, then it is necessary to wind a copper wire without insulation with a cross section of 4 or 6 mm 2 so that the end of the core is 3-4 cm longer. The result of such actions will be a decrease in the temperature of the soldering iron tip and more accurate work.
After the parallel-connected LEDs and the Chinese controller have become one garland, you can test it by connecting the do-it-yourself device to the network. A button on the case will allow you to switch flashing modes.
Parallel connection of LED strips
The segments of the LED strip when connected to the power supply should not be longer than 5 m. But if a large length is required, they are connected. But you need to do this only in parallel. Many “craftsmen” say that it is possible to perform sequential switching, but this is a very big mistake. The fact is that with such a connection, the load on the conductive threads of the first tape increases sharply, as a result of which they begin to burn out. But with a parallel connection of 12 volt LEDs, this does not happen - the tracks are designed for a strip length of up to 5 m.
LED strips are also used as garlands. Their most common use is Duralight-type street lighting. For its manufacture, a silicone tube is used, in which the LED strip is placed. Such garlands are frost-resistant and moisture-proof, not afraid of precipitation and dirt. They are used in the design of street Christmas trees, tree trunks, stretch between lampposts.
Features soldering SMD components
For the manufacture of LED-strips, SMD-mounted LEDs mounted on the surface are used. Their peculiarity is that without special equipment it is not possible to replace a burned-out element. The fact is that a station is needed here - it is easy to overheat chips with an ordinary soldering iron that do not tolerate too high a temperature. There are cases when too self-confident home masters managed to replace SMD components with a conventional device, but after 2-3 hours of continuous operation, the LED strip again failed.
In general, the LED strip is a universal device that is used in various fields. This may be the illumination of suspended ceilings, furniture, the interior of the car or a computer keyboard ... just not to list.
A few tips for creating a garland
Choosing the color of the future Christmas tree decoration, you should not pay attention to the RGB elements. Assembly for a novice master can become too complicated, and spending extra money to connect them like normal components afterwards will be an unacceptable luxury. It is best to parallelize the LEDs in different colors. Of course, you will have to make additional calculations of the parameters of the resistors, but the result will be much more interesting than when using solid emitters.
It is clear that the finished LED garland in the store is quite cheap. But it should be understood that a self-made product will seem many times more beautiful. And satisfaction from the fact that everything turned out as intended is not to be measured with any money.
In the manufacture of such jewelry, you should be extremely careful to ensure that there are no exposed areas, and the wires inside the controller do not overlap. Contacts must be soldered in a quality manner to avoid heating. It must be understood that it will be located on the tree, and the needles very quickly flare up due to the resin contained in it.
It makes sense to replace the power cable coming from the controller to the outlet - Chinese manufacturers are trying to save on everything. For this reason, the veins of this wire are slightly thicker than the hair. After opening the controller case, it makes sense to check the quality of the soldering of connections and contacts - in cheap models this is a sore spot.
Common Errors When Creating a Parallel Connection
No one is safe from this, but you should try to prevent this from happening. The main mistakes made not only by beginners, and sometimes by professionals, can be called:
- Ignoring the need to connect an LED with a limiting resistor.
- Switching multiple LED components through a single resistance. In this case, if one of the elements is broken, the current in the others will increase significantly. What it is fraught with, it is not worth talking.
- Serial connection of LEDs with various characteristics.
- Insufficient resistance. The current passing through the emitter will be too large, which will lead to an increase in temperature and failure of the element.
- Connecting LEDs to a household network without a reverse voltage limiting device. The network current is 220 V AC, which means that at the moment when the sinusoid crosses the axis, an element breakdown pn of the element will occur, which will lead to its failure.
- Low power of resistance. Even with the correct parallel connection of the LEDs, such an error will lead to strong heating of the resistor, melting of the insulation and short circuit.
It remains to advise home masters to be more attentive to such work and not to allow the listed errors.
Instead of an epilogue
Every self-respecting home master is obliged to know which connection is called serial and which parallel and be able to perform it. These skills are useful not only in the manufacture of garlands. Different types of connections can be encountered anywhere. For example, in the home electrical system, all sockets are connected in parallel, while the switches have serial switching. The main thing is to remember the basic rules, observe them and be attentive to the little things. In this case, any work that the home foreman will undertake will be performed safely, reliably and at the proper level.