New Year is the brightest and kindest holiday for the majority of the population of our country. People decorate Christmas trees and wait for something bright and kind. However, it is impossible to create a festive mood without the right illumination, which traditionally is garlands. They are made from incandescent bulbs, neon. However, LED products are rightfully considered the most economical and safe. Such garlands can be assembled even with your own hands. It is only necessary to follow some installation rules. Today's article will tell you about the parallel connection of LEDs, how it is done 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 used in its own area. For example, if we are talking about New Year's electric garlands, then a serial connection is more often performed here. It allows the use of incandescent bulbsor neon, designed for low voltage. For example, 4.5 V bulbs connected in series in the amount of 50 pcs. freely withstand a voltage of 220 V. With such switching, the plus of one emitter is connected to the minus of the other, and so on throughout the entire circuit.
But this rule does not apply to LED Christmas electric garlands. The fact is that the alternating current of the home network is not suitable for the correct operation of LED components. For normal operation, they need a stabilizing power supply. This means that the voltage in any case should be low. After all, it is much easier to stabilize 12V than 220V.
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 and neon lamps, and another for LED elements? It's about the characteristics of the emitters. Each of the LEDs 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 in series to it. It is for this reason that parallel switching is used in garlands.
Someone might say that it is enough to take a more powerful PSU, because at the same time it will be easier to control the voltage on the LEDs (it will be equal on each of them). But here comes the problem. Even if you take an ordinary garland of LEDs for 50 LED elements, the adapter will bebig enough to hide it under a small tree.
Useful information! If the voltage drop across the chips is higher than the rating of the power supply, such an adapter may not withstand long-term operation.
Parallel and series connection of LED components: video explanations
Some information about LED connections can be found in the following 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 that are as close as possible to each other in terms of characteristics. If the selection of LED-elements according to indicators is simple, then the resistance necessary for their correct operation must also be calculated. It is worth figuring out what formulas are used for this.
When LEDs are connected in parallel, the calculation of resistance should begin with the calculation of its nominal resistance, measured in ohms. To do 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. Data on LED elements is taken from the technical documentation.
For the normal operation of the circuit, the calculation of one more parameter will be required. When LEDs are connected in parallel, the calculation of the power resistor is also extremely important. It is produced in the following way. It is necessary to divide the squared difference between the voltage of the power supply and the LED element by the one obtained from the previous calculationsresistance.
How to make a garland of LEDs with your own hands
After calculating the resistors and soldering them to the cathodes of the LED elements, you should decide on the voltage of the power supply that will be used. The most convenient option is to use a controller from an old Chinese garland. This device will not only act as a stabilizer, but also eliminate the problem of how to make the LEDs flash 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 irradiated the cleaned places, you can solder the LEDs to them. The resulting soldering must be insulated together with a part of the LED element, as a result of which the strength of the connection will increase. For these purposes, it is better to use transparent adhesive tape, which will not interfere with the passage of the light flux.
Commutation of the resulting garland with the controller
If you open the case of a Chinese device, on the opposite side of the power wire, on the edge, you can see 2 or 3 output contacts. If there are 2, it is immediately clear how to solder, if there are 3, then the extreme ones are used, and the central one remains empty.
In such work, you should not use a powerful soldering iron with a thick tip - there is a danger of damaging the equipment. If there is no other way out, then it is necessary to wind a copper wire without insulation around the tip,with a section of 4 or 6 mm2 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 tip and more accurate work.
After the parallel-connected LEDs and the Chinese controller have become one garland, you can check it by turning on the device made by yourself in the network. The button on the body will allow you to switch flashing modes.
Parallel connection of LED strips
Segments of the LED strip when connected to the power supply should not be longer than 5 m. But if a longer length is required, they are connected. But you need to do this only in parallel. Many "craftsmen" say that serial switching can also be performed, but this is a very big misconception. 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 application is street lighting of the "Duralight" type. For its manufacture, a silicone tube is used, into 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, stretched between lampposts.
Features of soldering SMD components
SMD LEDs are used to make LED strips. Their peculiarity is that without special equipment it will not be possible to replace a burned-out element. The fact is that a station is needed here - it is easy to overheat chips that cannot tolerate too high temperatures with an ordinary soldering iron. There are frequent cases when too self-confident home craftsmen managed to replace SMD components using a conventional device, however, after 2-3 hours of continuous operation, the LED strip failed again.
In general, the LED strip is a universal device that is used in various fields. It can be the lighting of suspended ceilings, furniture, car interiors or computer keyboards… just to name a few.
Some tips for making a garland
When choosing the color of the future Christmas tree decoration, do not pay attention to RGB elements. Assembling for a novice DIYer can become too complicated, and spending extra money to then connect them as normal components will be a luxury. It is best to connect LEDs of different colors in parallel. 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 plain emitters.
It is clear that the finished LED garland in the store is quite cheap. But it should be understood that a hand-made product will seem many timesmore beautiful. And the satisfaction from the fact that everything turned out as planned cannot be measured by any money.
When making such decorations, you should be extremely careful, make sure that there are no bare areas left, and the wires inside the controller do not overlap. Contacts must be soldered with high quality, in order to avoid heating. It must be understood that it will be located on the Christmas tree, and the needles flare up very quickly due to the resin contained in it.
It makes sense to replace the power cable from the controller to the outlet - Chinese manufacturers are trying to save on everything. It is for this reason that the strands of this wire are slightly thicker than a hair. After opening the controller case, it makes sense to check the quality of soldering connections and contacts - in cheap models this is a sore spot.
Common mistakes when creating a parallel connection
No one is safe from this, but you should try to prevent this from happening. The main mistakes that are made not only by beginners, but sometimes by professionals, are:
- Ignoring the need to connect an LED with a limiting resistor.
- Switching several LED-components through one resistance. In such a case, if one of the elements is broken, the current on the others will increase significantly. What this is fraught with, it’s not worth talking about.
- Series connection of LEDs with different characteristics.
- Insufficient resistance. The current passing throughthe 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 limiter. The network current is 220 V AC, which means that at the moment when the sinusoid crosses the axis, the p-n junction of the element will break down, which will lead to its failure.
- Low power resistance. Even with the correct parallel connection of the LEDs, such a mistake will lead to a strong heating of the resistor, melting of the insulation and a short circuit.
It remains to advise home masters to be more attentive to such work and avoid the listed mistakes.
Instead of an epilogue
To know which connection is called serial and which one is parallel and to be able to perform it, every self-respecting home master is obliged. These skills will be useful not only in the manufacture of garlands. Various types of connections can be encountered anywhere. For example, in a home electrical network, all sockets are connected in parallel, while switches are connected in series. The main thing is to remember the basic rules, follow them and be attentive to the little things. In this case, any work that the home master undertakes will be done safely, reliably and at the proper level.
