In this article, we will look at a device that is sold in electrical goods stores as a dimmer for incandescent lamps. We are talking about a dimmer. Name "Dimmer" comes from the English verb “to dim” - to darken, become dim. In other words, you can adjust it with a dimmer. The remarkable thing is that the power consumption decreases proportionally.
The simplest dimmers have one rotary knob for adjustment and two terminals for connection, and are used to adjust the brightness of incandescent and incandescent lamps. Recently, dimmers have appeared to adjust the brightness of fluorescent lamps.
Previously, rheostats were used to adjust the brightness of incandescent lamps, the power of which was no less than the load power. Moreover, when the brightness was reduced, the remaining power was not saved in any way, but was dissipated uselessly in the form of heat on the rheostat. At the same time, no one talked about savings; they simply didn’t exist. And such devices were used where it was really only necessary to adjust the brightness - for example, in theaters.
This was the case before the advent of wonderful semiconductor devices - the dinistor and the triac (symmetrical thyristor). See: . In English-speaking practice, other names are accepted - diac and triac. They work based on these details. modern dimmers.
Dimmer connection
The dimmer switching circuit is incredibly simple - it couldn’t be simpler. It turns on in the same way as a regular switch - in an open circuit of the load power supply, that is, a lamp. In terms of installation dimensions and mounting, the dimmer is identical to the switch. Therefore, it can be installed in the same way as a switch - in a mounting box, and installing a dimmer is no different from installing a regular switch (). The only condition that the manufacturer imposes is to comply with the connection of the terminals to the phase and to the load.
All dimmers that are currently on sale can be divided into 2 groups - rotary, or rotary (with a regulator - potentiometer) and electronic, or push-button, with control using buttons.
When adjusting (dimming) with the potentiometer knob, the brightness depends on the angle of rotation. A push-button dimmer is more flexible in terms of control flexibility. You can connect several buttons in parallel and control the dimmer from any number of places. Of course, this is theoretical, in practice the number of control places is limited to 3-4, and the maximum length of wires is about 10 meters, and the circuit can be critical to interference and interference. Therefore, you must strictly follow the manufacturer's installation recommendations.
The price of dimmers with a regulator and with buttons differs by an order of magnitude, because a button dimmer (for example, a Legrand dimmer) is usually assembled with. Therefore, rotary dimmers are much more common, which we will consider below.
Rotary dimmer design and circuit
The rotary dimmer device is very simple, but may differ from one manufacturer to another. The main difference is in the quality of assembly and components.
The circuit of triac regulators is basically the same everywhere, differing only in the presence of additional parts for more stable operation at low “output” voltages and for smooth regulation.
The operating principle of the dimmer circuit is as follows. In order for the lamp to light up, the triac must pass current through itself. This will happen when a certain voltage appears between the electrodes of triac A1 and G. This is how it appears.
At the beginning of the positive half-wave, the capacitor begins to charge through the potentiometer R. It is clear that the charging rate depends on the value of R. In other words, the potentiometer changes the phase angle. When the voltage on the capacitor reaches a value sufficient to open the triac and dinistor, the triac opens.
In other words, its resistance becomes very small, and the light bulb burns until the end of the half-wave. The same thing happens with the negative half-wave, since the diac and triac are symmetrical devices, and they do not care in which direction the current flows through them.
As a result, it turns out that the voltage on the active load represents “stubs” of negative and positive half-waves, which follow each other with a frequency of 100 Hz. At low brightness, when the lamp is powered by very short “pieces” of voltage, flickering is noticeable. The same cannot be said about rheostat regulators and regulators with frequency conversion.
This is what it looks like real circuit of a brightness control (dimmer). The parameters of the elements are indicated taking into account the variation among different manufacturers, but this does not change the essence. In a practical circuit, any triacs can be installed, depending on the load power. Voltage - not lower than 400 V, since the instantaneous voltage in the network can reach 350 V.
The starting and ending points of ignition and the stability of the lamp’s combustion depend on the size of the capacitors and resistors. With a minimum resistance of the rotary resistor R1, the lamp will burn to a minimum.
If you really want to, you can try to make a dimmer yourself. There are a large number of different homemade dimmer circuits of varying levels of complexity. You can get acquainted with the circuits of homemade dimmers in more detail in a series of articles by Boris Aladyshkin about homemade dimmers -.
How to repair a dimmer
In conclusion, a few words about repairing dimmers. Most often, the cause of failure may be exceeding the maximum permissible load or a short circuit in the load. As a result, the triac usually fails. The triac can be replaced by unscrewing the radiator and removing the triac from the board. It is better to immediately install a powerful one, at a higher current and voltage, than a burnt one. It also happens that the regulator fails or the installation is disrupted.
The dimmer can be used as a voltage regulator, connecting any active load through it - an incandescent lamp, a kettle, an iron. But the main thing is that the dimmer power (in other words, the maximum current of the triac) must correspond to the load.
Energy-saving and durable LED lamps are modern technologies in lighting technology. Regulating lighting using dimmers will not only increase the economic effect, but also provide many additional opportunities for lighting control. What you need to know about LED dimmers?
By improving our home, we strive to make it convenient, comfortable and at the same time not too expensive. The visual perception of the interior and the comfortable stay of people in the house depend on lighting. The best option for organizing lighting is the ability to regulate the luminous flux of lamps depending on the situation.
Dimmers are dimmers that allow you to change the intensity of artificial lighting in a room. Regulation of the electrical power of the load occurs by changing the voltage in a rheostat, autotransformer or electronic.
Depending on the type of control signal, dimmers are:
Dimmers vary in type and power of lamps for which they are intended:
A dimmer for 220V LED lamps can be built into the lamp itself used for domestic purposes. Or it is a separate device and more powerful systems for theaters or light installations.
Their main difference from dimmers for incandescent lamps: to regulate the luminous flux, you do not need to lower or increase the current in the lamp.
LED lamps with a dimmer operate on the principle of pulse-width modulation, in which the LED is powered by DC pulses. The amplitude of such pulses is equal to the optimal current value. By varying their width, the brightness of the glow is changed.
At a high, up to 300 kHz, pulse frequency, the human eye perceives a set of pulses as an even glow.
Dimming does not reduce the service life of LED lamps. Compared to conventional LED operation, this saves up to 35% of energy consumption. Unlike incandescent lamps, dimming LED lamps works effectively in low light conditions.
In addition, there are a number of other advantages:
Dimmers vary in control method:
You can save energy by using not only modern lighting fixtures and indoor devices. For these purposes, it has been widely used. The layout and installation procedure of such a device depends on its design.
Many scientists took part in the history of the light bulb. you can find out what each of them invented in their time.
Depending on the installation method they are:
Not all LEDs are suitable for dimming lighting. Operating an LED lamp through a dimmer may affect its functioning. And besides, it may cause refusal of warranty service for the lamp.
Important! For the brightness control to work correctly, only LED lamps with a dimmer can be used with it.
Stores selling electrical goods offer dimmers from well-known companies:
Schneider Electric, Philips, LEGRAND and others, products from domestic manufacturers, dimmers made in Turkey and China. This allows everyone to find the best option for themselves in terms of functionality, ease of use, design and cost.
Those who are guided by the principle “the simpler the better” can purchase a dimmer controlled by a key or a rotary wheel. As a rule, these are inexpensive models that simultaneously perform the functions of a switch and a lighting regulator.
The electronic dimmer can be connected in parallel with the switch. You can turn on the light with a switch and change the illumination with a dimmer.
The acoustic dimmer will provide independent control from different places.
Dimmers with remote control cost many times more than simple models and, in addition to adjusting the light level, provide additional features: 
The possibility of dimming over a wide range, high luminous efficiency and efficiency of LED lamps make them increasingly in demand in the lighting products market. In addition to significant economic benefits, their use will make light not only a full-fledged element of the interior, but a means of changing it.
By adjusting the lighting, you can zone the room depending on the situation, highlight and highlight individual interior details. The use of dimmers and LEDs in smart home systems is especially promising.
Lighting a home is an integral part of a comfortable stay in it. For greater ease of use, modern light sources, especially LED lamps, are equipped with a special device - a dimmer.
Light
Such devices appeared almost immediately after the invention of incandescent electric lamps. Our article will tell you what this device is and why it should be installed in LED lamps.
Modern dimmer for LED light bulbs
A dimmer for LED lamps, as for other types of light sources, is a special device designed to change the brightness of the light. Such a device operates by limiting the current and, as a consequence, power.
At the very beginning, such devices were variable resistance. But in such a situation, a significant amount of power was dissipated in space in the form of heat. After some time, autotransformers are used to change the brightness of the lamps. They had significant dimensions, which made their operation uncomfortable.
Today, a modern dimmer is a complex electronic device that is capable of not only adjusting the brightness level of lamps, but also other functions. For example, using such devices you can turn off the lighting using timers, as well as smoothly start the lamps. Models that are equipped with a remote control can be adjusted remotely.
Note! Dimmers for LED lamps are the most popular models for private houses and apartments today.
Dimmers, as light level regulators, can be used for various types of lighting devices.
There are situations when the existing luminous flux emanating from LED lamps does not satisfy you in terms of its brightness. To be able to adjust this parameter, you need to buy and install a dimmer for this type of light source.
Note! This device will be especially relevant if there is a periodic need to change the level of illumination in the room.
LED lighting in the apartment
In order for the dimmer to work in conjunction with LED lamps, the design of the lamp must contain a choke. These types of devices are designed for lower power when comparing this parameter with conventional light bulbs.
Note! LED lamps are approximately 10 times less powerful than conventional light bulbs. Therefore, to work with them, dimmers with lower power are needed.
Another feature of such devices is that to adjust their operation there is no need to lower or increase the current. In this situation, the brightness of the LED lamps can be adjusted by changing the current pulses in the network. When the pulsation frequency reaches 300 kHz, a flickering effect will appear in the lamp. This effect will be invisible to the human eye.
All devices with which you can regulate the level of illumination have a similar structure. Externally, they look like a switch, which is equipped with a rotating wheel. Modern models can be equipped with buttons or a touch panel.
Touch control dimmer
Each device contains in its design two connections to the circuit. You can connect such a device in the same way as a regular switch. You just need to connect the wires to the terminals correctly. You can use it in exactly the same way, only the list of possibilities will be many times wider.
Such devices operate on the following principle: the brightness of the lamps can change due to changes in current pulses in the network. In this case, only the pulse width changes, not its power. Thus, the dimmer operates on the principle of cutting off the voltage amplitude.
By turning the wheel clockwise or by pressing a key/sensor, the lighting in the room will become brighter or dim.
LED lighting products today are represented by a variety of products:
Variety of LED products
An LED lamp is a separate device that is standardized specifically for connection to an existing electrical network.
LED lamps have the following characteristics:
Note! If the light bulb must operate at a voltage of 12 volts, then this must be specified in the plan for the use of additional devices.
Structure of an LED lamp
The LED light bulb contains the following components:
Note! The driver is a device that provides power to the LED components in the light bulb. It stabilizes the current flowing through the diodes. At the same time, it can be used for dimming.
To control the brightness level in a conventional lighting system, many leading manufacturers produce special LED bulbs. The packaging of such products always contains the inscription “brightness adjustment” or “dimmable”.
Packaging a light bulb that can be adjusted
Such light sources operate according to the usual scheme, but their driver is capable of responding to the behavior of a standard dimmer. When the knob is turned, the driver begins to generate current pulses with a higher or lower duty cycle. This way you can adjust the brightness of the light by 10%. It is with this brightness that the light bulb will light up when the dimmer is turned on.
This product costs a little more than regular products. But it has additional capabilities that will not be superfluous in a high-quality lighting system.
Dimmers are quite widely represented on the lighting market today. All their diversity can be divided into the following groups:
Modular dimmer
Monoblock regulator
Remote block
Also, dimmers, according to the control method, have the following classification:
Note! With rotary-push dimmers, you can turn off the load by placing the control in a certain position.
You can use any type of dimmer in your home.
Not all dimmers can work with LED light bulbs. Here you can use the following options:
Note! Some dimmer circuits may not work correctly with drivers from certain manufacturers.
Therefore, today leading manufacturers of light bulbs (for example, Osram and Philips) work in conjunction with tracking manufacturers of regulators: Legrand, ABB, SchneiderElectric. There are special tables to assess such compatibility.
Dimmer and driver compatibility tables (example)
Remember that when selecting a regulator, it is necessary to take into account the power of the existing light source.
The question about the advisability of using dimmers to regulate the illumination level of LED lamps is quite difficult to answer. After all, any regulator will cost money, and besides, it still needs to be selected and installed correctly. Therefore, many in this situation ask the question “are dimmers needed at all?” To answer this question, it is worth considering the advantages of such regulators. These include the following points:
Dimmer for LED lamps with remote control
At the same time, the only drawback of such a lighting system is the additional costs of purchasing and installing equipment.
Tsugunov Anton Valerievich
Reading time: 4 minutes
Switches with a brightness control or dimmers (from the English dim - dim, darken) are a device that can regulate the voltage at the consumer in the range from 0 to 100% of the nominal. Most often, dimmers are used instead of conventional switches to smoothly adjust the brightness of light.
The main purpose of such devices is to regulate the brightness of incandescent or halogen lamps. Halogen lamps that operate at reduced voltage are controlled using a dimmer connected through a step-down transformer. These devices can be purchased separately, but it is better to buy a dimmer with a built-in transformer.
Attention! To work in lighting circuits with LED and fluorescent lamps, it is necessary to use special dimmers.
To control energy-saving lamps, devices are used whose design includes an additional element - an electronic starter.
Using the brightness control as a light switch, you can arbitrarily change the lighting intensity from maximum to dimmest. In this case, there is no need to use double or triple switches to control the operation of chandeliers with several lamps. In addition, it makes no sense to purchase expensive lamps equipped with their own voltage regulators.
There are currently several types of monoblock dimmers on the market:
In addition to monoblock dimmers, there are devices with modular control, which is carried out using a remote button or a key switch. Such regulators are used to control lighting in public places, as well as for installation in distribution boxes.
As already mentioned, most dimmer models are designed for use in circuits with incandescent or LED lamps.
When choosing a dimmer, you need to pay special attention to its power, which must exceed the total maximum power of all consumers connected through this device. Today, in electrical goods stores you can find light controllers with a power of 40 W to 1 kW.
As for the design, there are single, double and triple dimmers on the market. Moreover, the vast majority are single models.
In addition to its main purpose - smooth adjustment of light, some dimmer models can be equipped with additional elements that allow you to perform a number of useful functions, which include:
The main element of the dimmer design is the electrical circuit, which is designed to reduce the effective value of the voltage supplying the load.
Ensuring reliable operation of this circuit is carried out using several types of protection, which include protection against short circuit, overvoltage and overheating.
Like a regular light switch, the dimmer has a metal frame that allows you to easily install it in a standard socket box.
The main element of the electrical circuit on which the dimmer switch is built is a bidirectional triode thyristor - a device that is an electronic switch controlled by a short pulse.
One of the most common brightness control circuits is shown in the figure.
The signal to open and close the thyristor is supplied using a capacitor of a certain capacity, which accumulates charge during the passage of the first half-wave of the supply voltage.
Modern dimmers are not consumers of electrical power. This is their fundamental difference from earlier analogs that operated using an active or capacitive voltage divider circuit.
Previous generations of voltage regulators were either rheostats connected in series with the load or autotransformers. In both cases, the manufacture and use of such devices turned out to be extremely expensive. The use of a rheostat, in addition to significant financial costs, led to a significant increase in the weight of the light controller. In addition, when current flows through the rheostat, it becomes very hot, which leads to significant power losses and forces the need to consider the need to cool this device.
Unlike a rheostat, an autotransformer is not a consumer of energy, but it has an extremely large mass and dimensions.
It is possible to avoid power losses in the dimmer due to an electrical circuit that allows you to supply power to consumers by “cutting off” the front or rear part of the half-wave of the supply voltage. This operating principle is called phase control with cutting off the leading or trailing edge.
The operating principle of a dimmer that cuts off the leading edge of a half-wave of a voltage sine wave:
The figure shows the shape of the supply voltage in a circuit whose circuit contains a controlled thyristor, which is automatically turned on when the voltage reaches zero.
Depending on the operating mode, which is determined by the response time (from 0 to 9 ms), it is possible to achieve a smooth change in the power consumed by the lighting device.
The connection of a single brightness control is carried out according to the same scheme as the installation of an ordinary key switch. Thus, when installing a dimmer instead of an existing switch, there is no need to make any changes to the electrical wiring design.
The connection diagram, as well as the dimensions of the socket box and the marking of the terminals are absolutely identical.
Some difficulties may arise only if the light dimmers are connected as pass-through switches or combined into groups controlled by a remote control. A diagram of their connection of three outputs for connecting electrical wires.
Advantages:
Flaws:
Thus, the use of dimmers as lighting regulators is completely justified in cases where a smooth change in the brightness of the light is really necessary. At the same time, due to the high cost of these devices, using them instead of all switches in the apartment seems impractical.
Adjusting the brightness of light sources is used to create comfortable lighting in a room or workplace. Brightness adjustment is possible by installing several circuits that are turned on by separate switches. In this case, you will get a step change in illumination, as well as separate lamps on and off, which can be inconvenient.
Stylish and current design solutions include smooth adjustment of the overall illumination, provided that all lamps are lit. This allows you to create both an intimate environment for relaxation and a bright one for celebrations or working with small details.
Previously, when the main light sources were incandescent lamps and spotlights with halogen lamps, there were no problems with adjustment. Used (or thyristors). Which was usually in the form of a switch, with a rotary knob instead of keys.
With the advent of energy-saving (compact fluorescent lamps) and then LED lamps, this approach became impossible. Recently, the vast majority of light sources are LED lamps and light bulbs, and incandescent lamps are prohibited for use for lighting purposes in many countries.
It’s interesting that on the packaging of domestic incandescent lamps they now indicate something like: “Electric heat emitter.”
In this article, you will learn about the principle of LED dimming, as well as what it looks like in practice.
Operating principle:
You change the base current by changing the voltage drop across the emitter-base junction using potentiometer R2, resistors R1 and R3 are needed to limit the current when the transistor is maximally open, calculated based on the formula:
R=(Usupply-Udrops on LEDs-Udrops on transistor)/Ilight.nom.
I checked this circuit, it regulates the current through the LEDs and the brightness of the light quite well, but some steps are noticeable at certain positions of the potentiometer, perhaps this is due to the fact that the potentiometer was logarithmic, or perhaps due to the fact that any pn junction of the transistor is the same diode with the same current-voltage characteristic.
A current stabilizer circuit is better suited for this task, although it is more often used as a voltage stabilizer.
It can also be used to obtain a fixed current at a constant voltage. This is especially useful when connecting LEDs to the vehicle’s on-board network, where the voltage in the network when the engine is off is about 11.7-12V, and when the engine is running it reaches 14.7V, a difference of more than 10%. It also works great when powered by a power supply.
Calculating the output current is quite simple:
This results in a fairly compact solution:
This method is not characterized by high efficiency; it depends on the voltage difference between the stabilizer input and its output. All voltage “burns out” on the LM. Power losses here are determined by the formula:
P=Uin-Uout/I
To increase the efficiency of the regulator, a radically different approach is needed - a pulse regulator or a PWM regulator.
Brightness control methods: PWM control
PWM stands for “pulse width modulation.” It is based on turning on and off the power supply to the load at high speed. Thus, we get a change in current through the LED, since each time it is supplied with the full voltage required to turn it on. It quickly turns on and off at full brightness, but due to the inertia of vision, we do not notice this and it looks like a decrease in brightness.
With this approach, the light source may produce pulsations; it is not recommended to use light sources with pulsations of more than 10%. Detailed values for each type of premises are described in SNIP-23-05-95 (or 2010).
Working under pulsating light causes increased fatigue, headaches, and can also cause a stroboscopic effect, where rotating parts appear to move. This is unacceptable when working on lathes, drills, etc.
There are a great variety of circuits and design options for PWM controllers, so listing them all is pointless. The simplest option is to assemble a PWM controller. This is a popular chip. Below you see a diagram of such an LED dimmer:
But in fact, this is the same circuit, the difference is that the power transistor is excluded here and it is suitable for regulating 1-2 low-power LEDs with a current of a couple of tens of milliamps. Also excluded from it is the voltage stabilizer for the 555 chip.
How to adjust the brightness of 220V LED lamps
The answer to this question is simple: they are practically not regulated - i.e. no way. For this purpose, special dimmable LED lamps are sold; this is written on the packaging or with a dimmer icon.
Perhaps the widest range of dimmable LED lamps is presented by GAUSS - in different shapes, designs and bases.
Why you can’t dim 220V LED lamps
The fact is that the power supply circuit of conventional LED lamps is built either on the basis of a ballast (capacitor) power supply. Or on the diagram. 220V dimmers, in turn, simply regulate the effective voltage value.
The following dimmers are distinguished according to the area of operation:
1. Dimmers that cut off the leading edge of the half-wave. These are the types of circuits most often found in household regulators. Here is a graph of their output voltage:
2. Dimmers that cut off the trailing edge of the half-wave (Falling Edge). Various sources claim that such regulators work better with both regular and dimmable LED lamps. But they are much less common.
This implies:
Conventional LED lamps will hardly change brightness with such a dimmer, and this can also speed up their failure. The effect is the same as in the rheostat circuit given in the previous section of the article.
It is worth noting that most cheap dimmable LED lamps behave exactly the same as regular ones, but are more expensive.
Adjusting the brightness of LED lamps - a rational 12V solution
12V LED lamps are widely used in spotlight sockets, such as others. The fact is that often these lamps do not have a power supply circuit as such. Although in some it is installed at the input, this does not affect the possibility of regulation.
This means that you can regulate such light bulbs using a PWM controller.
In the same way as adjusting brightness. The simplest version of the regulator, like this on the wiring, in stores they are usually called: “12-24V dimmer for LED strip.”
They can withstand, depending on the model, about 10 Amps. If you need to use it in a beautiful form, i.e. built in instead of a regular switch, then on sale you can find such 12V touch dimmers, or options with a rotating handle.
Here is an example of using such a solution:
Previously, they were powered by electronic transformers, and this was an excellent solution. 12 volts is a safe voltage. To power these 12V lamps, an electronic transformer will not work; you need a power supply for LED strips. In principle, this is what converting lighting from halogen to LED lamps is all about.
Conclusion
The most reasonable solution for adjusting the brightness of LED lighting is to use 12V lamps or LED strips. When the brightness decreases, the light may flicker; for this, you can try using a different driver, and if you make a PWM controller with your own hands, increase the PWM frequency.
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