A dimmer is a small-sized device designed to smoothly adjust the brightness of the glow of one or more lamps. Most often, it is a control knob, by rotating which we can change the level of illumination. The adjustment process is called dimming. Often you can find lamps, floor lamps and chandeliers already with a built-in dimmer. It can also be purchased separately atradio stores, it is not expensive, but allows you to create more comfortable conditions for lighting residential and non-residential premises, because bright lighting is not always necessary. You can buy a dimmer in our store.
It is important that not all lamps are dimmable. For example, you can use a dimmer with absolutely all incandescent and halogen lamps, and fluorescent (often called "energy-saving") and LED lamps are not always dimmed. That is why, if you purchase an LED lamp and want it to work in a luminaire with a dimmer, then you need to pay attention to this characteristic in the description of the lamp. When describing lamps in our product catalog, this item is called "dimmable" and if "yes" is indicated in this description item, then the lamp is dimmable and it suits you.
More on Dimmer
The term "dimmer" comes from the English word "dim" - dimming. In the simplest case, it can be a variable resistor (rheostat). Recently, small-sized electronic dimmers have become most widespread, where a semiconductor triac or transistor switch is used as a power element.
The simplest and most common dimmers in household appliances carry only one function - a smooth adjustment of light. However, there are much more modern and "advanced" dimmers that can perform other interesting and useful functions that increase comfort and quality of life in general:
- automatic switching on and off of the lamp by timer or other electronic control program;
- imitation of presence;
- various modes of dimming and blinking;
- remote lighting control: via infrared, radio, acoustic (clap, noise with a given level) or with voice control.
Dimming can be performed automatically, for example, according to the level of illumination, using an ambient light sensor to maintain a given level of illumination in the room. Dimming can help save energy on lighting, since an automatic dimer that works in conjunction with a lamp always shines just as much as you need without spending extra energy, for example during the day, in cloudy weather or when the room is irregularly illuminated by street light, you can even out lighting by indoor light sensors and maintain the desired level using the dimming function.
Automatic dimming can also be used as a warning function, provided that the light turns off soon or when the light is turned on to avoid dazzling.
Our company, in addition to selling LED lamps and luminaires, is engaged in the development, production and implementation of lighting control systems. In the event that you have an idea how to make the lighting in your apartment, house or office more manageable (more difficult than turning it on and off), we will be happy to help you. You can read more about our services on our separate website on lighting control systems.
LED Lighting Articles
This article is for those who first asked a similar question and do not have a technical education. LED lighting is lighting something using relatively new light sources - LEDs. An LED is an industrial crystal that, when connected to electricity, starts to emit light. Frankly speaking, the LED cannot be called a new light source, because it was invented several decades ago, but it began to be actively developed and used in all spheres of our life only at the beginning of 2000, thanks to new discoveries in the technological field and a significant reduction in the cost of production.
Modern technologies do not stand still and scientific and technological progress does not disregard such a sphere of our life as lighting. The development takes place both in the direction of increasing lighting characteristics, and in the direction of the appearance of additional related technological devices that increase the usefulness of lamps and the lighting system in general. We are talking about the many varieties of LED lights with integrated sensors.
We decided to make a review, which will collect the most interesting reviews about LED lamps. We collected these reviews both from our customers (and continue to collect), and from the Internet - from various forums, blogs, thematic portals and other resources. Having received a large amount of data, we systematized it, depersonalized it, and we got a certain set of interesting opinions and tips from real people using LED lamps at home, in the country, in the office, etc.
Customers of our online store often ask questions - which LED lamps are the best, which companies? What exactly are they better? Can the characteristics of the lamps indicated on the packaging be trusted? Can I buy LED lamps made in China? Can I use LED lamps in children's rooms? This is only part of the questions that customers ask when choosing the best option for themselves. Moreover, such questions arise when the buyer already knows what type of lamp is needed and with what characteristics. In this article we will try to give answers to all these questions and avoid new puzzles for the consumer :-)
A LED is a semiconductor device that converts electric current into light radiation. The LED has a common abbreviation - LED (light-emitting diode), which in literal translation into Russian means "light-emitting diode". An LED consists of a semiconductor chip (chip) on a substrate, a housing with contact pins, and an optical system. The direct emission of light comes from this crystal, and the color of the visible radiation depends on its material and various additives. As a rule, there is one crystal in the LED housing, but if it is necessary to increase the power of the LED or to emit different colors, several crystals can be installed.
This is, of course, the most important question, since the world today is on the verge of a new era in lighting technologies and we must be sure that LED lighting does not harm our health. To date (2014), this issue cannot be considered thoroughly studied, since the period of implementation of LED lighting in human life is still quite small and the necessary amount of statistical data for analysis has not yet been accumulated. Nevertheless, at the moment there are a huge number of facts and opinions of professionals in this field, indicating the absence of any harm from LED lighting.
This article is for those who do not understand light bulbs, types of their socles and electricity in general, but already understand that using LED lamps is much more economical than incandescent and even luminescent lamps (they are often called "energy-saving"). It is very simple to choose the right LED lamps and we will help you make the right choice, following the instructions below. Or you can immediately call us and we will be happy to help you with a choice.
In this article, we will talk about the benefits of using LED lamps compared to fluorescent (often called "energy-saving"), halogen and incandescent lamps. In the second part, we present an economic calculation of the payback when replacing lamps with LED ones. The economic efficiency of LED lamps is so obvious that you do not need any special knowledge in order to draw conclusions yourself.
One of the tasks that are often encountered during deep repairs or the construction of residential and office premises is the level of adequate lighting. In a situation where conventional incandescent lamps are used as light sources, from experience one can approximately determine the required number and power of light bulbs, but if there is an idea to make housing more modern and convenient, and at the same time regularly save significant amounts on lighting, then it makes sense to look at the LED lighting. So, how many and what kind of LED lamps do you need to install in order to be comfortable in the room?
In one of our articles, we talked about what an LED is and how it developed. Now we want to dwell on the current industry leaders - those who produce LEDs and LED lamps. This is not the same thing, since lamp manufacturers do not always make LEDs and vice versa, LED manufacturers do not always engage in mass production of lamps based on them. According to the official data of IMS Research, in February 2013, LED production is concentrated in China (more than 50%), then Taiwan (about 20%), South Korea (about 10%), Japan, the USA, Europe and other regions (20% in total) .
This article is a practical guide for those who are going to make global repairs in an apartment or house and are considering how to make the lighting of a future home convenient, comfortable, unique, easy to maintain, but at the same time economical and environmentally friendly. Today, indeed, there is something to think about, since LED lighting is becoming very inexpensive. The choice of power, size and appearance of the light sources is very rich and you can not limit your imagination. Where to start? How to approach the task? To do this, you need to understand what exactly you want to do, and then find the most effective solutions from both a practical and economic point of view. It is not as difficult as it seems and we will be happy to help you with this.
In our online store you can purchase LED lamps and LED lamps, choosing them for the task of lighting any object. But our activities are far from limited to sales only - our team also includes experienced engineers in the field of design, production, installation and further operation of lighting control systems. Our partners are many engineering and design companies, with which we can implement projects for lighting systems of objects of any scale and complexity. This activity of our company is presented on the market as a WLightiT project.
In this article we will touch upon a very important topic - office lighting. A third of the lives of most people go to work, so the quality of lighting in the workplace is the key to well-being and productivity. That is why when planning lighting in an office building, it is important to consider the main factors affecting the quality of lighting. The quality of lighting is influenced even by such seemingly trifles as the color of the walls, the arrangement and material of the furniture. In our article, we briefly classify office luminaires so that you have a first idea of \u200b\u200bthe variety of lighting solutions in office lighting, but we will focus on office luminaires implemented using LEDs as light sources.
Devices designed to adjust the brightness of the light are called dimmers from the English word to dim - dim. The simplest option for a dimmer is a variable resistor, connected in series with the lamp. Its disadvantages are obvious - low efficiency and the need to provide heat sink from the resistor at high powers.
A more effective option is the use of the so-called laboratory autotransformer (LATR). In it, you can adjust the tap to which the load is connected. The supply voltage of the lamp changes, respectively, its brightness changes. Such a device has high efficiency, but very cumbersome, which complicates its mass use. Therefore, in modern dimmers, a different principle is used.
How does a dimmer work?
A sinusoidal electric current flows in the network. Brightness can be adjusted by applying a cropped sine wave to the lamp. To do this, in series with the load, you need to put a switch that will pass current only when the absolute voltage value exceeds a certain value. In this way, the power supplied to the lamp can be changed. The output is no longer a smooth sinusoid, but a broken line. In order to reduce the level of interference, a choke is placed in series with the dimmer.
Thyristor-based dimmer device is very simple
A schematic diagram of a thyristor dimmer as an example of the simplest and cheapest option is shown in the figure. Such a device can easily be assembled with your own hands, of course, in compliance with all safety regulations regarding working with high voltage. The devices manufactured by the industry have a slightly different scheme, but the principle of the dimmer remains the same.
The dimmer is connected to open the lamp power circuit. Usually possible dimmer connection instead of a conventional switch, so most dimmers are designed for installation in standard fittings.
Dimmers for incandescent lamps differ in the type of semiconductor device that interrupts the current: on thyristors, triacs, bipolar transistors, field effect transistors.
In industrial dimmers, triacs are used instead of thyristors. According to the principle of operation, the triac is similar to a thyristor, but passes current in both directions. This allows you to do without a diode bridge, on which part of the power is lost. At the household level, as well as in trade catalogs and popular literature on radio electronics, dimmers on triacs are often called thyristor, although this is not entirely true.
A more complex option is bipolar transistor dimmers, which are more versatile. Finally, dimmers on field-effect transistors have better parameters (but also a higher price).
Dimmers on thyristors and triacs cut off the leading edge of a sinusoid. Transistor dimmers can cut both the leading edge of the sine wave (marking RL) and the trailing edge (marking C).
When using dimmers of the listed types together with incandescent lamps, there are no problems. The lamp has an inertia and sums up the power that is supplied to it. In addition, the incandescent lamp has virtually no capacitance and inductance, so the shape of the sinusoid and the presence of a constant component do not affect it.
The situation is different when the dimmer is used with energy-saving lamps. Then the search for the answer to the question "how to choose a dimmer" becomes more difficult.
Halogen bulbs
For halogen incandescent lamps (GLN) with a supply voltage of 220 V, as a rule, standard dimmers for conventional lamps are suitable. The dimmer for halogen lamps as a separate type of device is almost never found, although functions can be added to a conventional dimmer to increase the life of the HF. When using GLN for a voltage of 12 V, the lamps are connected to the network through a step-down transformer.
The step-down transformer can be winding or electronic. As a result of the asymmetry of the cutoff of the sine wave, a constant component can be present at the output of the dimmer, which can damage the winding transformer. Therefore, the dimmer must be adapted to work with inductive loads. Use dimmers marked RL.
The electronic transformer is a capacitive load, so you need to use dimmers with the mark C for it.
In any case, a dimmer and transformer compatible with each other should be used. The best option is to combine a dimmer and an electronic transformer in one device. However, in practice, this can only be done in “smart home” systems, where a control signal is supplied to a transformer with adjustable output voltage. The reason is that to minimize energy losses, the transformer must be located as close to the GLN as possible, and the dimmer control knob is located at some distance, on the wall.
The dimming threshold for GLN is 0%. Nevertheless, the principle of operation of the GLN implies the presence of a tungsten-halogen cycle, when the tungsten deposited on the walls of the bulb returns back to the filament. When the power supplied to the lamp decreases below a certain level, the tungsten-halogen cycle stops. There is still no consensus among specialists whether this phenomenon can reduce the life of the GLN. If the GLN constantly works in the low-brightness mode, then gradually the walls of its bulb darken due to the tungsten deposited on them. If this phenomenon occurs, it is recommended that the lamp be turned on at full power for 10 minutes.
Etren Q600 dimmer has a slow start function, useful when using halogen lamps
Some dimmers have a soft start function, which allows you to gradually increase power when turned on. There are also dimmers, which provide for a smooth decrease in power when turned off. These functions significantly increase the service life of the HF, which are affected badly by sudden voltage drops.
Metal halide lamps and DNaT
It is widely believed that metal halide lamps (MGL) are generally not amenable to dimming. In fact, for some modern MGL models, dimming is possible using a special electronic ballast.
MGL dimming threshold is only 50%
It has been established that for MGL it is preferable to feed with rectangular current pulses than a sinusoidal current. By adjusting the pulse width at a constant frequency, you can adjust the power supplied to the load and thereby change the brightness of the lamp.
The MGL color temperature changes significantly with a change in the power supplied to it. In addition, with reduced power, the MGL operates in a non-optimal mode, which is characterized by a decrease in light output and a decrease in service life. For all these reasons, dimming of metal halide lamps is rarely used in practice. One of the few examples is spotlights for reporting television shooting, powered by a battery. They are in low brightness mode, and at the time of shooting are translated in maximum brightness mode. Dimming makes sense, since it can take several tens of seconds to start the MGL.
The principle of operation of high pressure sodium lamps (DNaT) is almost the same as that of MGL. Accordingly, dimming is carried out in the same way. Only some lamp models are suitable for dimming. When dimming DNaT, the service life is reduced. Dimming of DNaT is not widespread.
The minimum dimming threshold for MGL and DNaT is 50%.
Linear Fluorescent Tubes
With conventional fluorescent lamps, the use of a dimmer for incandescent lamps is not possible. Here you need a ballast with a dimmer.
When using electronic ballasts, power is supplied to the fluorescent lamp at a frequency of 20 - 50 kHz. A choke is connected in series with the fluorescent lamp, and a capacitor in parallel, which form a resonant circuit. When the lamp is started, the operating frequency becomes close to the resonant, due to which an increased voltage on the electrodes is provided and a discharge is obtained. When a trigger occurs, the operating frequency changes to a lower one. By varying the frequency, it is possible to regulate the current flowing through the lamp, and, therefore, the brightness of its glow.
Dimming fluorescent tubes allowed Feelux Lighting to implement the SIH system
An important point here is that the start parameters are independent of the dimming level. This is a fundamental difference from compact fluorescent lamps with integrated ballasts.
Almost all modern linear fluorescent lamps from leading manufacturers are dimmable, and dimming practically does not affect the service life. And if, instead of turning off the fluorescent lamp, it is dimmed for a while, then this approach even increases the life of the lamp, since it is the frequent on and off that reduce the service life.
The threshold for dimming fluorescent lamps from leading manufacturers reaches 5%.
Dimming fluorescent tubes allowed Feelux Lighting to create Sun in House (SIH) technology, which translates as “sun in the house." Thanks to it, it is possible to change the color temperature of the lighting depending on the time of day or simply at the request of the user. Two dimmable lamps are taken, one with a color temperature of 2200K, and the other with 8000K. By changing the ratio of light levels of these lamps, you can adjust the color temperature over a wide range. In addition to special lamps, a special controller is required, which is a universal ERP with a two-channel dimmer.
Compact fluorescent tubes
There are two types of compact fluorescent lamps (CFLs): without ballasts and with integrated ballasts. The former are dimmable in the same way as ordinary fluorescent lamps. The latter either do not dim at all, or work with dimmers for conventional incandescent bulbs.
The principle of operation of a dimmable compact fluorescent lamp with integrated ballast is the same as that of a conventional CFL. In order for CFL to be dimmable, it must have the ability to start at low power. This is due to the fact that the power to the lamp and the starting device is supplied through the same contacts. The power of the dimmable CFL is usually at least 18 watts. The fact is that to maintain a discharge in CFLs, a power of at least 1.8 W is required (for inexpensive lamps this threshold can be on the order of 6 - 7 W), respectively, for lamps of lower power, the dimming depth will be too small. An important nuance: first you need to bring out the dimmer control at least a third of the maximum power so that the lamp starts, and then reduce the illumination to the required level.
The dimming threshold for CFL can reach 10%. For example, Osram and Feelux Lighting managed to achieve this value. Other manufacturers typically have a dimming threshold of 15-30%.
The main problem of dimming compact fluorescent lamps with built-in ballasts is associated with faster wear due to starting with insufficiently heated electrodes. This is due to the fact that the dimmer reduces the power supplied to the entire device, including the lamp electrodes. In this regard, dimmable CFLs are manufactured with a large “safety margin”. Naturally, they are much more expensive than conventional compact fluorescent lamps.
LEDs
The brightness of the LED can be adjusted by changing the strength of the current flowing through it. However, this path is fraught with some problems. Firstly, there is an optimal mode in which the LED has maximum light output. Deviation from it leads to a decrease in the efficiency of the LED. Secondly, when the current of the white LED changes, the shade of the glow changes.
For these reasons, a different method is used for dimming LEDs. The LED is supplied with direct current pulses, the amplitude of which is equal to the optimal current value. The width of the pulses varies, while the brightness of the glow changes. The pulse frequency is selected very high (up to 300 kHz), so that flicker is not felt.
The dimming threshold for LEDs is 0%, although it is not achieved in real-life models of luminaires, simply because not to increase the cost of electronic components. Dimming practically does not affect the life of the LEDs.
In addition to LED lamps, LED lamps are also produced for lampholders E14, E27, GU10 and GU5.3, designed to replace incandescent or GLN lamps.
Philips has managed to create an LED lamp that can work with conventional dimmers
Most models of such lamps are not dimmable. However, in 2008, Philips introduced the second-generation Master LED lamps, which can work with conventional incandescent dimmers. The company has not yet disclosed the principle of operation of these lamps in dimming mode.
Leditron Interface
The creation of CFLs and LED lamps that can work with dimmers for incandescent lamps leads to waste of money. Complex and expensive devices are created that allow you to adjust the brightness of the glow by changing the power supplied to the light source. A much more economical way is to remotely control the electronics built into the lamp, while the power supply to the lamp does not change.
Osram Intelligent Dim - an experimental CFL model with Leditron interface
To realize this idea, Osram in collaboration with renowned dimmer manufacturers Berker, Gira, Jung and Insta proposed the Leditron interface, which provides control signals to CFLs and LED lamps with standard socles. Now the technology is in the standardization stage, but by the end of 2010, the first serial samples of products with its use should appear. The Leditron interface was presented at Light + Building 2010. Data on the operating principle underlying Leditron has not yet been published. It is only known that the interface can be used to control not only the brightness, but also, with respect to LED lamps, the color of the glow. It can be assumed that control signals are transmitted at a high frequency via network wiring simultaneously with power.
conclusions
Perhaps the most important reason why it is now worthwhile to use LEDs for lighting is the combination of high light output and the ability to dimming over a wide range. DNaTs still beat LEDs in terms of light output, but they are very difficult to dimming, moreover, the dimming threshold is 50%. Of all energy-saving light sources, only GLN and LEDs have a zero dimming threshold. Dimming has no effect on the life of the LEDs; for some other types of lamps, the life may be reduced.
Some characteristics of energy-saving light sources
| Source type | Typical luminous efficacy, lm / W | Dimmability | Dimming Threshold,% | The effect of dimming on the service life |
| GLN | 11 - 20 | almost all models | 0 | can both increase and decrease |
| MGL | 70 - 100 | some models | 50 | reduces |
| DNT | 80 - 150 | some models | 50 | reduces |
| LL | 50 - 60 | all modern models of leading brands | 5 | does not affect |
| CFL | 50 - 60 | some models | 10 | reduces |
| LED | 50 - 100 | everything except some lamp models for standard socles | 0 | does not affect |
The gain from the use of LEDs will be especially noticeable in “smart home” systems, where brightness is adjusted over a wide range depending on the presence of people in the room, the time of day, and other factors. When using such a system, significant energy savings are achieved even in comparison with light sources having large light output.
To adjust the brightness of incandescent lamps, a dimmer was invented a long time ago - a simple electronic device that changes the brightness of the lamp due to the "cutting" part of the sinusoid of the mains voltage.
The incandescent lamp is simple, and the LED lamp contains a complex electronic circuit, so with dimming everything is not easy there. Today I will tell you what dimmers do, how they differ among themselves, and how dimmable LED lamps behave compared to incandescent lamps when adjusting brightness.
Let's start with what dimmers do. Here is a voltage waveform.
The dimmer "cuts off" a piece of a sinusoid. At half brightness, “halves” of the sinusoid remain in each half-cycle.
At a minimum brightness level, only small “tails” remain.
In fact, the dimmer switches the load on and off 100 times per second and the brightness depends on the moment of switching on.
All dimmers with a two-wire connection cannot “open” completely - for operation they need power, which they receive due to the small voltage remaining with an incomplete “opening”. At maximum brightness, the waveform at the dimmer output looks like this.
When turned on via a dimmer, ordinary LED lamps will turn on at full brightness from a certain moment of regulation or blink when trying to dim. Dimmable LED lamps allow you to adjust the brightness, which contain a special circuit that recognizes dimming and controls the lamp stabilizer circuit.
When dimming, LED bulbs behave differently from incandescent bulbs. When the incandescent lamp burns very weakly, the LED lamp still glows quite brightly. This is how the lamps look, connected via the same dimmer at minimum brightness.
All dimmers have a different minimum level. For example, in one of the Chinese dimmers, the waveform at the minimum level looked like this.
At the same time, LED dimmable lamps glowed quite brightly.
For dimming LED lamps, it is important that the minimum level of adjustment is as low as possible. If the filament of the incandescent lamp at the minimum level of adjustment glows a little dark red, such a dimmer is suitable for LED lamps, if the filament of the filament lamp is yellow, the LED lamps at the minimum dimming level will shine too brightly.
I connected the incandescent lamp to the three dimmers that I have and measured the output voltage with a standard multimeter (it should be noted that in this case it is incorrect to measure the voltage with a multimeter, but for comparison the results will be quite suitable).
The black Chinese dimmer on the wire is 59 V.
IKEA Dimmer - 34 V.
Chinese dimmer with shiny handle - 19 V.
The maximum level for all dimmers is also different:
Online - 225 V.
Black Chinese dimmer on the wire - 187 V.
IKEA Dimmer - 211 V.
Chinese dimmer with shiny handle - 205 V.
Dimmable LED lamps differ in the minimum level of dimming. Some allow you to reduce the brightness to 5%, and some only up to 20%. Here, for example, the Navigator NLL-C37-5-230-2.7K-E14-FR-DIMM and IKEA 102.667.54 lamps, included in the same dimmer at a minimum brightness level.
Another problem when dimming LED lamps is sound. Almost all dimmable lamps quietly itch when dimming, but some lamps with some dimmers begin to hum quite loudly. The dimmer itself can itch.
Another problem is the incompatibility of dimmers with LED lamps. Some dimmers "go crazy" when LED bulbs are turned on. I have a Univex switch in my room with dimming and remote control. When LED lamps are screwed into the chandelier, the light turns off immediately after being turned on. Replacing one of the six lamps with a conventional incandescent lamp helped. Now there are five LED lamps and one incandescent lamp in the chandelier and the switch works correctly.
The last problem is the incompatibility of the lamps and the dimmer. However, some LED lamps may not turn on or turn on once. For example, of the six lamps in the chandelier, when turned on, only five or four can be lit, and when turned on again, all six will be lit. The reason most likely is the interference introduced by the dimmer. For a Chinese black dimmer at half brightness, the output waveform looks like this:
It is possible that the interference pulse affects the operation of the lamp electronics.
1. All dimmers have different minimum levels. LED lamps need to be as low as possible;
2. The maximum level is also different. If it is not high enough, the lamps will never burn at full brightness;
3. All dimmable LED lamps have a different level of minimum dimming;
4. Incompatibility of the lamp model with the dimmer model is possible;
5. When dimming, the lamps may hum, when changing the dimmer, the hum may decrease.
p.s. That's how I spend my day off. 🙂
You can create a unique and inimitable backlight in your home today with the help of a wide variety of lamps. One of the most commonly used lighting products is LED strip.
They are indispensable in the decorative illumination of a wide variety of interior elements, furniture and ceiling suspended structures. Due to the extensive list of possibilities of such lighting products, it is widespread and very often found both in home lighting and in the illumination of various offices and public premises. A new level of use of such LED strips is their dimming. We will talk about him in more detail.
Lighting Improvement
LED strips at this time are very popular lighting products. Such popularity is explained by their unique lighting capabilities and the availability of creating with their help a wide variety of lighting effects.
But, unlike LED lamps, tapes must be connected to the mains through additional drivers adapters.
Note! Unlike tapes, LED lamps are often equipped with a control circuit.
Additional adapters include the following products:
- dimmer;
- power Supply;
- control block
Additional adapters
The operation scheme, when a power supply is required, creates certain difficulties during the operation of LED strips. But on the other hand, by connecting a dimmer to the circuit, you can achieve a certain option for controlling the luminous flux created by an already dimmed tape. Thus, a dimmed tape is a tape in the wiring diagram of which, along with the power supply, there is also a dimmer.
Features of Dimmable LED Products
LED strip in its design has a semiconductor LED. To dimming led strips, you need to understand how it works and how it should be connected to the power supply.
Note! Such a semiconductor has a non-linear current-voltage characteristic or CVC. This means that the current flowing through it starts only from a certain threshold value. In this case, the current rises very strongly, which can lead to burnout of the LEDs.
VAC LED
To avoid such a negative development, it is necessary to connect the LED strips to the power supply only through a transformer (that is, a power supply).
Note! In this situation, a transformer or power supply will reduce the network voltage from 220 volts to the desired value, for the LED strip to work adequately (up to 12 or 24 volts). Such devices can be called "sources of stable current."
LED Strip Power Supply
In the simplest situations, you can use a conventional resistor for these purposes. But remember that its resistance for the stable operation of led strips should be large. The EMF of the voltage source should also be high. Despite its apparent simplicity, creating such a scheme is not easy. In this situation, loss of electrical power will occur. Therefore, in order to compensate for such losses, LED strips must be connected to a low-voltage source, which at the same time can stabilize the output current. The role of such a low-voltage source is a power supply unit or a transformer.
For LED lamps, the power supply is already built into the design, but for tapes it has the appearance of a separate module.
At the output, such a transformer has an output voltage of 24 or 12 volts (depending on the type of LED strip). At the same time, the limiting resistors for it will be placed on the tape itself.
Note! If you are dealing with a dimmer or control unit, then they also need to be selected according to the power of the purchased tape.
Proper dimming implies the correct connection of all components, including the power supply (aka transformer), control unit or dimmer, as well as the lighting products themselves.
LED strip connection diagram
Only in the situation when the connection scheme is observed, the glow of the ribbons will be bright and full. If something was connected incorrectly, then the backlight simply won’t work until the installation inaccuracies are corrected.
Ways to adjust the brightness
LED Strip Dimmer
One of the main reasons why LED strip has become so popular today is that you can easily attach a special device to it with your own hands - a dimmer. It allows you to change the lighting intensity in the room.
If there is such an element in the circuit, the tape will be called “dimmable”.
Note! You can use such a dimmer suitable for LED strips only there. It is not suitable for interaction with conventional energy-saving bulbs. Otherwise, you risk incapacitating the entire system.
For LED strips, there are two main types of dimmers:
- passive. Their role is played by variable resistors (potentiometers and rheostats). This is the simplest way to adjust, but it is characterized by a loss of power, which negatively affects its energy efficiency (it decreases);
Note! Here, due to the high nonlinearity of the I – V characteristic of the LED, a situation arises that was described above (there are large energy losses). It cannot be leveled even when using potentiometers with a logarithmic characteristic to change the resistance.
- active regulating dimmer circuits based on semiconductor devices.
The last type of dimmers, in turn, is divided into two subgroups:
Analog dimmer
- analogue. They make it possible to maintain the output current at a stable level and in the required range with a small voltage drop. As a result, there is a slight loss of power on the LED strip;
Note! The disadvantages of such products include the fact that when the parameter of the operating current flowing through the LED in the range of 20 ~ 100 mA is often changed, the dissipated power is often observed. This, in turn, leads to a change in the temperature of the device. But with strong heating of the LED, significant changes in its technical characteristics occur.
- impulse. They are more modern models, devoid of many of the shortcomings of analog dimmers. Most often today, to control the level of glow of LED strips, pulse-width modulators (PWM) are used. For LED products, these are the most effective dimmers.
As you can see, for an LED strip, a pulse dimmer will be the best choice for adjusting brightness. It, when properly connected, will allow you to efficiently and conveniently control the level of light flux emitted by the LEDs.
The principle of operation of pulse width modulators
Since pulse-width modulators are used today to control LED strips most often, we will consider their principle of operation in more detail.
Pulse Width Modulator
The principle of their action is to change the duration of the working fraction of the period for a rectangular pulse current, as well as the duration of its supply to the product. These parameters are determined relative to the zero level. The fraction of the period when the maximum voltage is observed is implied. This parameter is called latitude. Its changes occur in the range from 0 to 100%, causing characteristic changes in the value of the available voltage of the light source.
Note! In this situation, the output current remains stable, and at the most optimal level.
In this case, the spectral composition of the light flux cannot be changed, and the dissipated power will be kept in the range of nominal values.
It is worth noting that the loss of the dimmer itself during operation in pulsed mode remains minimal. It is also necessary to know that such regulators are best suited for connecting a computer and digital method of controlling the level of illumination.
The disadvantages of such models include increased flicker. It is typical for cheap devices. Such a phenomenon can occur even at insignificant levels of brightness and it is harmful to the eyes. Prolonged observation of such a lighting effect can lead to various negative consequences:
- the appearance of unpleasant visual sensations;
- headache development;
- fatigue;
- decreased attention and visual acuity.
To avoid such a negative impact on your body, you must give preference to better and more expensive models.
How to connect a dimmer
To dim the LED strip, it is necessary to correctly connect not only the transformer (power supply), but the dimmer itself. It should be remembered that there are various types of LED emitters mounted on LED strips:
- RGB - tri-color. When mixing their glow, a white light is obtained. And if you turn them on separately, you can get a wide variety of color effects;
Color glow ribbon
- phosphoric. They are used as secondary radiation for a special yellow phosphor layer, which is illuminated by powerful blue type LEDs. To power them, you should use special drivers (power supply and transformer), as well as dimmers.
Therefore, the choice of the connection scheme, as well as the type of dimmer itself, must be done based on the parameters of the purchased LED strip. For example, for white single-crystal tapes, you need to use single-channel dimmers, which are connected in the circuit after the transformer has been installed.
Connection Diagram Option
If you choose the right dimmer, then your LED backlight will be regulated in the best way.
Adjustment options
Remote control dimmer
In addition to the above-described options for regulators, which are widely used today to change the characteristics of the level of light flux, the dimmers themselves may differ from each other depending on the control method. So, the dimmer can be controlled:
- using a potentiometer. In this situation, it is built into the wall standard switch box;
- through a connection to a computer network via a special interface Ethernet, Bluetooth or Wi Fi;
- using the radio frequency and infrared remote control.
Separately, it is worth noting that the dimmer modules can be produced both separately and as part of combined devices. In the latter case, in one case, it will be combined with the driver.
Another way to control brightness
Thyristor dimmer
In addition to the most dimmers, to obtain the ability to control the luminous flux of LED strips, today they use special dimmable power supplies. They are a special type of voltage source that has the ability to control the brightness of the device to which they were connected. Most often, in a tandem with LED tapes, a thyristor dimmer is used. It is best suited for a dimmable power supply.
Such products can be shared with incandescent lamps.
Dimmable power supply can significantly increase the life of led products, just properly stabilizing the voltage. It will save led from sudden voltage drops, which often serve as the main cause of breakdowns of various electrical devices. In addition, this product has an aesthetic appearance and is not difficult to install.
Conclusion
There are several options for making an LED strip dimmed. Each of them has its own advantages and disadvantages. But all of them allow you to create a comfortable and efficient system for quality control of the brightness of light sources. In favor of which particular method to make a choice (a dimmable power supply or installing a dimmer), depends on some of the criteria described in the article. Remember that the key to success here will be not only the right choice of the dimmer, but also its correct installation.