home Boiler room Switches with a brightness control - dimmers for different types of lamps. LED dimming in general and in detail LED backlight control

Switches with a brightness control - dimmers for different types of lamps. LED dimming in general and in detail LED backlight control

Very often there is a need to regulate the brightness of the lamp within a certain value, usually from 20% to 100%. Setting the brightness lower does not make sense, since most lamps simply do not work in this mode or provide a tiny amount of light, which is only enough to glow the lamp, but it will not illuminate anything. You can go to the store and buy a ready-made device, but now the prices for these devices are very high and do not correspond to the product received. Since we are jacks of all trades, we will make these devices ourselves. Today we’ll look at several diagrams that will help you understand how to make a 12 V and 220 V dimmer with your own hands.

On a triac

First, let's look at the circuit of a dimmer operating from a 220-volt network. This type of device operates on the principle of phase shifting the opening of a power switch. The heart of the dimmer is the RC circuit. The control pulse generation unit, which is a symmetrical dinistor. And in fact, the power switch itself that controls the load is a triac.

Let's consider the operation of the circuit. Resistors R1 and R2 form. Since R1 is variable, it changes the voltage in the R2C1 circuit. Dinistor DB3 is connected to the point between them and when the voltage reaches its opening threshold on capacitor C1, it is triggered and supplies a pulse to the power switch - triac VS1. It opens and passes current through itself, thereby producing voltage at the output. The position of the regulator determines which part of the wave will go to the lamp. The faster it charges, the faster the key opens, and most of waves and power will go to the load. Thus, the circuit literally cuts off part of the sine wave. Below is the operating schedule of the device.

The value (t*) is the time during which the capacitor is charged to the opening threshold of the power element. This dimmer circuit is simple and easy to repeat in practice. It works best on incandescent lamps, due to the fact that the spiral in the lamp is inert, but problems may arise with LED and other lamps, so it is necessary to check the functionality of the circuit specifically on your consumers before final installation. We recommend watching the video below, which clearly shows how to make a dimmer on a triac:

Triac power regulator 1000 W

On thyristors

You don’t have to buy a triac, but make a simple dimmer using thyristors, which can be easily obtained from old non-working equipment and boards, like TVs, tape recorders, etc. The circuit is slightly different from the previous one in that each half-wave has its own thyristor, and thus its own dinistor for each switch.

Let us briefly describe the regulation process. During the positive half-wave, capacitance C1 is charged through the chain R5, R4, R3. When the opening threshold of dinistor V3 is reached, the current through it enters the control electrode of thyristor V1. The key opens, passing a positive half-wave through itself. When the phase is negative, the thyristor is turned off, and the process is repeated for another switch V2 and capacitor C2, which is charged through the chain R1, R2, R5.

Phase regulators - dimers can be used not only to adjust the brightness of incandescent lamps, but also to regulate the rotation speed of the hood fan; you can make an attachment for a soldering iron and thus regulate the temperature of its tip to improve the quality of soldering.

Video assembly instructions:

Thyristor dimmer assembly

Important! This control method is not suitable for working with fluorescent, energy-saving compact and LED lamps due to the nature of their operation.

Capacitor dimmer

Along with smooth regulators Capacitor dimmers have become widespread in everyday life. The operation of this device is based on the dependence of alternating current transmission on the capacitance value. The larger the capacitor's capacity, the more current it passes through itself. Thus, using a capacitor, you can reduce the power supplied to the lamp, but this method does not allow for smooth adjustment. This type of homemade dimmer can be quite compact, it all depends on the required brightness parameters, and therefore on the capacitance of the capacitor, which is related to its size.

As can be seen from the diagram, there are three positions: 100% power, through a quenching capacitor (power reduction) and off. The device uses a non-polar paper capacitor, which can be obtained from old equipment. We talked about that in the corresponding article!

Below is a table relating capacitance and lamp voltage.

Based on this circuit, you can assemble a simple night light yourself and use a toggle switch or switch to control the brightness of the lamp.

On the chip

To regulate the power supplied to the load in circuits direct current 12 Volts, often use integral stabilizers - Krenki. The use of a microcircuit simplifies the development and installation of devices due to the small number of radio components. This homemade dimmer is easy to set up and has some protection functions.

By using variable resistor R2 creates a reference voltage at the control electrode of the microcircuit. Depending on the set parameter, the output value is adjusted from a maximum of 12 V to a minimum of tenths of a volt. The disadvantage of these regulators is low efficiency and the maximum possible power of the connected load; as a result, there is a need to install an additional radiator for good cooling of the KREN, since part of the energy is released on it in the form of heat. However, it is ideal for low power DC and low voltage circuits due to its simplicity and versatility.

This lighting controller was repeated by me and did an excellent job with a 12 Volt LED strip, three meters long, and made it possible to adjust the brightness of the LEDs from zero to maximum.

An excellent option is a dimmer on an integrated timer 555, which controls the KT819G power switch and short PWM pulses. By setting the circuit to a high frequency, you can get rid of flickering, which often occurs due to cheap commercial dimmers and causes rapid fatigue and irritation of the human eye.

In this mode, the transistor is in two states: completely open or completely closed. The voltage drop across it is minimal, which allows you to connect a more powerful load and use a circuit with a small radiator, which compares favorably with the previous circuit with a ROLL regulator in terms of size and efficiency.

Making a 12 Volt light controller

That's all the ideas for assembling a simple dimmer at home. Now you know how to make a dimmer with your own hands for 220 and 12V.

Switches with dimmer control are becoming increasingly popular. These devices are designed to regulate consumer voltage in the range from 0 to 100 percent of the rated value. Nowadays they are increasingly used instead of classic switches to smoothly change the brightness of the light flux.

Application area

Most often, these devices are used to regulate the brightness of halogen light bulbs and classic incandescent lamps. Moreover, in the first case, there is one nuance of using a dimmer switch - it must be connected to the light source exclusively through a step-down transformer. This device can be purchased separately or you can use a ready-made solution.

It is also necessary to remember that special switches are produced that regulate the brightness of LED and fluorescent lamps. The fact is that their design contains one important element - an electronic starter. Thanks to the use of lighting regulators instead of conventional switches, it is possible to smoothly change the intensity of the light flux from minimum to maximum values.

This is not only convenient, but also eliminates the need for multi-button switches to control chandeliers with multiple bulbs. The situation is similar with complex and lighting devices equipped with their own regulators - it is much cheaper to purchase a dimmer and connect a chandelier to it.

Dimmer classification

Today you can find three main types of monoblock adjustable light switches on sale:

Devices equipped with a mechanical regulator made in the shape of a disk - their design is very simple, which has a positive effect on the cost. They can have a push or turn mechanism.
Dimmers with push-button adjustment - have a more complex design, but at the same time the functionality expands, for example, control can be carried out using a remote control.
Touch devices are the most expensive dimmers with the widest functionality.

On sale you can find not only monoblock switches with a brightness control, but also devices with a modular design. Such dimmers are controlled using a key switch or remote button. They are practically not used in residential premises . Choosing a dimmer, you need to pay attention to the power of the device. This indicator must exceed the total power of all consumers connected to the switch.

A few words should be said about the additional functionality of dimmers:

The ability to create the effect of presence.
Several dimming modes, including flashing lights.
Automatic switching on and shutdown.
Remote or voice control.

Design Features

This is a rather complex device when compared with classic switches. The main design element is electrical diagram, the task of which is to reduce the voltage to the required value to power the dimmer. To ensure reliable and uninterrupted operation With this scheme, manufacturers use several types of protection, for example, against power surges and overheating.

The main element of the circuit is a bidirectional triode thyristor. This is an electronic switch that controls a short pulse. To supply a signal to open and close the thyristor, a capacitor with a certain capacitance is used. During the passage of the first wave of supply voltage, it accumulates charge, after which it transfers it to the thyristor.

Principle of operation

All modern light controllers are not consumers electrical energy- this is their main difference from the first models. Earlier analogues worked in accordance with a capacitive or active voltage divider circuit. In essence, they were autotransformers or rheostats connected in series with the main energy consumer.

In each of the situations considered, production and use dimmers was quite expensive. For example, if a rheostat was used, this increased the mass of the entire device and also led to strong heating. As a result, manufacturers had to look for ways to effectively dissipate heat, and this affected the cost of the dimmer. The autotransformer, although not an active consumer of energy, has large dimensions.

Modern luminous flux power controllers use a special electronic circuit, which allows you to supply power to the lighting device, “cutting off” the back and front parts of the voltage half-wave. This operating principle of dimmers is called “phase control with cutting off the trailing and leading edges.” In accordance with the operating mode, determined by the response time (this indicator is 0−9 ms), it is possible to achieve smooth adjustment of power consumption.

Advantages and disadvantages of dimmers

Among the positive properties of all devices of this type it is worth noting:

However, dimmers also have several disadvantages:

If we are talking about connecting a single dimmer, then there should be no problems. During installation of such a device, there is no need to make changes to the apartment's electrical wiring diagram. If a person at least once changed the switch, then you can easily connect a light controller, because the markings of all terminals are the same.

Lighting a home is an integral part of a comfortable stay in it. For greater ease of use modern sources Lights, 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.

Dimmer purpose

Modern dimmer for LED light bulbs

Dimmer for LED lamps, as for other types of light sources, is a special device designed to change the brightness of the glow. 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 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 lighting fixtures.

Features of devices designed for LED lamps

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.

Design and principle of operation of dimmers

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 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.

Compatibility of LED light bulbs with dimmers

LED lighting products today are represented by a variety of products:

separate LEDs;
LED strips;
LED bulbs.

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:

standard base: type G, type E – threaded (E14 and E27), type MR;
can work from standard electrical network 50 Hz, 220 V without the use of special and additional devices;

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.

luminous flux similar to those for standard light bulbs.

Structure of an LED lamp

The LED light bulb contains the following components:

diffuser;
LEDs that are mounted on a special board;
drivers, thanks to which the required operating mode of the light source is ensured;

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.

systems through which the product is cooled during its operation;
standard plinth;
ventilation holes.

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.

Range of control devices

Dimmers are quite widely represented on the lighting market today. All their diversity can be divided into the following groups:

modular. They are placed on DIN rails in distribution panels. They are used very widely. Such devices can be used to adjust the brightness of lighting, create lighting effects, and also as part of the Smart Home system. The control mechanism here is carried out through remote controls and buttons. The regulator is located in the installation box. It can be installed instead of a switch. Such a device is controlled using a switch or buttons;

Modular dimmer

monoblock devices. They can also be mounted in a mounting box. It is the most common type of device of this kind. Such a dimmer is installed and connected in the same way as a simple switch - into a phase wire break;

Monoblock regulator

remote blocks. Used to connect spotlights equipped with LED bulbs. They are controlled by radio or infrared remote controls, as well as remote panels and conventional dimmers.

Remote block

Also, dimmers, according to the control method, have the following classification:

rotary. In this situation, a rotary knob is used that rotates clockwise and counterclockwise;
rotary-push. To turn on the device, you need to press the knob, and the control process itself is carried out by a standard turn of the knob;

Note! With rotary-push dimmers, you can turn off the load by placing the control in a certain position.

push-button (keyboard). There are keys on the front panel that can be used to decrease or increase brightness;
sensory. These are the most modern models. Control here is carried out by touching the touch panel.

You can use any type of dimmer in your home.

Compatibility of regulators with LED lamps

Not all dimmers can work with LED light bulbs. Here you can use the following options:

standard control devices LED light bulbs;
special PWM dimmer.

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.

Relevance of using regulators

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:

implementation of a flexible and easily controlled lighting system;
reduction of energy costs;
lack of high heat generation;
installation of regulators operating from a remote control will greatly increase the comfort of using the lighting system;

Dimmer for LED lamps with remote control

the ability to change the color of the glow and create various lighting effects.

At the same time, the only drawback of such a lighting system is the additional costs of purchasing and installing equipment.

A modern dimmer for LED lamps has a complex electrical circuit, the work of which is to regulate the luminous flux. In addition, it serves as surge protection, acts as a load distributor and saves electrical resources, extending the life of the lamps.

Regulators for 220 V LED lamps are similar in functionality and structure to models for other light sources. In general, this is a switch with an adjustment wheel or buttons. The housing has circuit connections for connecting wires. The functionality of the regulator is to cut off the voltage amplitude. By turning the wheel or pressing buttons, the brightness of the lamp, and therefore the entire lighting, changes. Dimmers for LED lamps have their own characteristics:

The dimmer cannot be used to adjust the brightness of each lighting cycle. It's better to do this periodically. If you need less brightness of the light each time you turn it on, you need to install lower power lamps in the lighting fixtures;
To operate a dimmer with LED lamps, you definitely need a choke. This is due to the fact that such models are designed for less power;
LED lamps have 10 times less power than conventional light sources, which requires the use of low-power dimmers for them;
and finally, their main difference is adjustment. The brightness of LED lamps is regulated not by decreasing or increasing the current, but by changing its pulses in the electrical network.

It is these features that indicate why LED lamp dimmers cannot be installed with other types of lamps. The switch and lamps must be compatible.

Difference in management

Exist different types dimmers for LED lamps, which differ in their control:

Mechanical control is performed by a button or wheel. The mechanism can be rotary, push or turn-push. Turning the wheel or pressing a button changes the brightness of the lighting;
electronic control has a switch that has a touch or infrared sensor;
acoustic adjustment occurs due to the presence of a sensor that responds to loud sounds, for example, a person’s voice. The disadvantage of such control is an unplanned change in the brightness of the lighting due to the sound of accidentally falling objects;
Remote adjustment is performed via the control panel. With this dimmer it is convenient to adjust or turn on the lighting without leaving your seat.

Of all the models considered, the rotary switch can be considered the most reliable. Its mechanism is simple and affordable. When performing installation, it is easiest to find components. Legrand is considered one of the main and popular manufacturers of dimmers.

Difference by installation type

Modern models of LED dimmers have a wide range, which differ in the type of installation:

modular models are mounted on a DIN rail and placed in the distribution board. They are controlled through remote regulators. In addition to changing the brightness of the lamps, the switch has additional functions;
monoblock models are quite common. They can be installed instead of a regular switch, but they must have a PWM function;
Depending on the type of installation, regulators are available for hidden and external electrical wiring.

What is PWM?

PWM stands for pole width modulation. It is used to adjust the glow of LED lamps. The principle of operation of a PWM generator is to generate a high-frequency current of about 200 Hz, which is required for the operation of an LED lamp. A change in the brightness of the glow occurs from a change in voltage, width and time of the positive pulse. An electrical signal is generated at the output of the PWM generator, while the frequency and magnitude of the current do not change.

LED lamp compatibility

To find out which dimmer you need to purchase, you need to determine its compatibility with the light source. Since LED lamps are adjustable and unregulated, not every dimmer can be installed in the circuit. Some manufacturers produce LED lamps that work with a specific regulator. Their compatibility can be determined using tables available from sellers of this type of product. Before installing a dimmer, you need to study specifications light sources:

Unregulated lamps cannot be installed together with a dimmer. This will lead to their poor performance, and if they fail, the seller or manufacturer will refuse warranty service.
Dimmable lamps often operate with standard regulators, which operate on the principle of phase cutoff. But here you need to know that the quality of lighting dimming is affected by the number of LEDs on the switch. Most regulators require a minimum load of 20-45 watts for optimal operation. If 1 incandescent lamp is enough to achieve such power, then 2 or 3 LED lamps with a voltage of 220 V will have to be connected.
If you only need to use 1 LED lamp for lighting, it is better to use a low voltage regulator. It is designed to regulate low-voltage LED lighting, which has a magnetic transformer.

When purchasing an LED lamp, you need to pay attention to the packaging. Manufacturers indicate on it whether a regulator can be used. This could be an inscription or a round icon.

Calculation of the maximum number of lamps

When choosing a regulator for DIY installation on home lighting its power must be taken into account. It will not be possible to calculate the maximum number of 220 V LED lamps using the principle of calculating conventional light sources. The easiest way is to consult a specialist or, if you use 1 220 V lamp to illuminate the room, take it with you to the store and test it for performance by connecting it to a regulator.

But if you decide to do the calculation yourself, let's look at the differences between conventional and LED sources light 220 V:

the number of conventional light sources can be calculated by dividing the maximum power of the regulator by the power of one lamp;
to calculate the maximum number of 220 V LED light sources, you need maximum power regulator divided by 10. The resulting result is divided by the power of the LED lamp.

Self-installation of the regulator

The process of connecting the regulator with your own hands is quite simple:

Turn off the power supply at the electric meter.
At the installation site, you need to trim the electrical wiring and strip the ends of the wires.
Apply electricity to the network and use a tester or probe to find the phase wire. After this, the electricity must be turned off again.
On the regulator, connect the phase wire to the connector with the letter L, and insert the other wire into the connector with the letter N. After this, clamp the wires with clamps and check the strength of the connection.
After the entire circuit is assembled, set the dimmer level by adjusting it with the adjusting bolts.
Attach the decorative casing on top and, after applying voltage, test the operation of the system.

On at this stage, if all lighting devices work normally, installing the regulator yourself can be considered complete.

Homemade regulator

The homemade dimmer circuit is quite simple. If you have a soldering iron at home and you can solder radio components yourself, of course, it is advisable to have at least minimal radio skills.

To make a regulator with your own hands you will need copper wire, triac, two capacitors, dinistor, variable and constant resistors, as well as a soldering iron with solder. Install the radio components on the textolite board, and solder them together with a wire as indicated in the diagram.

Principle of operation homemade circuit consists of supplying current from a variable resistor to a non-polar capacitor. In turn, it charges and releases energy to the lamp. If the circuit is assembled correctly and all parts are functional, the regulator should work.

By installing the dimmer yourself LED lighting 220 V, the owner will take a step towards creating high-tech housing.

In contact with

Dimming with in English translated only as “darkening”. What a dimmer is, what they are and where else they can be used we will tell you in this article. From origins to final implementation. The most important question is: can LED lamps be used with a dimmer?

What is a dimmer and why is it needed?

A dimmer is an electronic device capable of regulating power by regulating the voltage supplied to the load. The definition is very dry and boring, let's get more in simple language Let's explain the principle of operation.

Power depends on the voltage and current in the load. This means that if you reduce one of the components, the power will also decrease. Voltage and current are related by Ohm's law, which means you can reduce the power of your device (brightness of the lamp) by increasing the total load resistance. That is, use ballast resistors, chokes or capacitors.

Ballast power absorbers - convert excess energy into heat and have low efficiency. To regulate the power of the device, in our case the brightness of the light bulb, you need another device - a dimmer.

Is it possible to connect LED lamps via a dimmer? Can. But not everything will be consistently regulated. Here you need special LED lamps for dimmer.

LED lamps, dimmable , Suitable for use with any regulator. But there are some nuances in the difference between the type of voltage regulation. This is determined by the dimmer's circuitry; the differences will be described in detail in the following sections of the article. The type of dimmer determines how well the LEDs will be regulated.

Which LED lamps can be used with a dimmer? In this matter, everything is extremely individual. It all depends both on the circuit of the light bulb itself and on the circuitry of the regulator. In general, the so-called dimmable LED lamps.

What types of dimmers are there?

Power regulators can be divided into two large groups:

For work in alternating voltage circuits (220V);
for use in circuits DC voltage(for 12V LED strip).

Drills also need a regulator to adjust the speed; it is located in the button.

It can be used for a variety of purposes, listed in order of popularity:

Light brightness adjustment, dimming of LED and incandescent lamps;
adjusting the heating element temperature in various heaters;
adjusting the speed of the commutator motor.

What are the differences between dimmers?

If you are going to use a switch with brightness control, you first need to find out what they are. And in general, can all LED lamps be dimmed?

Dimmers differ according to the following criteria:

By type of installation;
on execution and method of management;
according to the method of regulation.

Let's take a closer look at each of them.

By installation type

For outdoor installation– surface-mounted switch with dimmer for LED lamps. To install such a device, you do not need to drill a niche in the wall; it is simply mounted on top of the wall. It is very convenient to use in cases where the interior is not a priority or external wiring is installed.

For indoor installation – will fit perfectly into any interior, such as this one.

For DIN rail mounting are very specific and at first may seem that they are not practical. However, this dimmer for LED lamps works with a remote control, and is hidden from prying eyes in the electrical panel.

By execution

According to the design, the light controller for LED and incandescent lamps can be:

Rotary;
rotary-push type;
push-button;
sensory;

Turning- one of the most simple options LED lamp brightness control, looks unpretentious and has simple functionality.

Turn-push looks almost the same as the rotary one. Thanks to its design, when you press it, the light turns on with the same brightness as it was set the last time you turned it on.

Push-button regulator For LED lighting It looks more technologically advanced and will fit organically into a modern apartment. Like this switch with a dimmer for LED lamps.

Touch models and can be completely different - from luminous circles to smooth one-color panels for adjusting the voltage of LED lamps.

According to the adjustment method

Dimmers vary not only in their design, but also in their operating principle. E This applies specifically to AC dimmers.

The first type of dimmers is more common and cheaper, due to the simplicity of its circuit - this is leading edge cutoff dimmer(English) leading edge). A little further on, its operating principle and circuit will be discussed in detail; for comparison, take a look at the type of voltage at the output of such a regulator.

The graph shows that the remainder of the half-wave is supplied to the load, and its beginning is cut off. Due to the nature of the load switching on, interference is generated in the electrical networks, which interferes with the operation of televisions and other devices. A voltage of the set amplitude is applied to the lamp, and then it fades out when the sine wave passes through zero.

Can a leading edge dimmer be used for LED lamps? Can. LED lamps with a dimmer of this type will only be well adjustable if they were originally designed for this. This is evidenced by the symbols on its packaging. They are also called “dimmable”.

The second type works differently, creates less interference and works better with different light bulbs - this trailing edge cutoff dimmer(English) falling edge).

LED lamps with this type of dimmer adjust better, and its design better supports non-dimmable light sources. The only drawback is that these lamps can adjust their brightness not from “zero”, but within a certain range. At the same time, dimmable LED lamps are simply superbly adjustable.

The best solution is to use a Falling Edge dimmer for LED lamps.

A special word can be said about ready-made LED lamps with adjustable brightness. This is a separate class of lighting devices that do not require the installation of additional regulators, but have them in their design. Their adjustments are made using buttons on the case or from the remote control.

Dimmer circuits

Dimmer for 220V voltage, with leading edge cut-off, works on the principle of phase-pulse voltage control. During operation, the elements of such a dimmer supply voltage to the load at certain moments, cutting off part of the sinusoid. This is depicted in detail and more clearly in the graphs.

Area of the sine wave, shaded gray– this is the voltage area or its effective value that is supplied to the load (lamp or any other device described above).

The red dotted line shows the voltage waveform at the dimmer input for led lamps. In this form, it is supplied through a regular switch without adjustments .

How to connect LEDs via a dimmer?

Component ratings and all information are indicated on the dimmer diagram.

The device is installed in a break in the wire going to the light source, motor, heating element or any other device.

The logic of the circuit is as follows: capacitor C1 is charged through chain R1 and potentiometer R2. Depending on the position of the potentiometer, the capacitor is charged to the opening voltage of the dinistor VD1.

The circuit used a DB3 dinistor, which is approximately 30V. Through an open dinistor, a control pulse for opening a triac (bidirectional thyristor) is supplied to its control electrode.

The greater the resistance set by the potentiometer knob, the longer it takes for the capacitor to charge, respectively, the later the dinistor-triac circuit will open, and the voltage will be lower, since most of the sine wave will be cut off. And vice versa - less resistance means more voltage at the output of the regulator.

There are many options for circuits on the Internet with all sorts of modifications, all of them are good. Here is simplest scheme, the figure shows the installation of this version of the circuit.

How to adjust LED lighting

What light bulbs can be used with a dimmer? When mainly incandescent lamps were used for lighting, everything was simple - a regular dimmer could easily cope with adjusting the brightness.

Incandescent light bulbs were replaced by energy-saving fluorescent light bulbs and could not be dimmed at all. Of course, there were electronic ballasts for tubular fluorescent light bulbs with the possibility of dimming, but extremely rare and they were expensive.

Now energy-saving lamps are being replaced by LEDs. The process of emitting light quanta, although complex, is, from a regulatory point of view, perhaps simpler than regulating gas-discharge light sources.

Dimmable LED lamps - what are they?

What does dimmable LED lamp mean? This is a light bulb that can be dimmed using ANYONE dimmer, which is designed for alternating or direct current (depending on the type).

Its power circuit includes functions for changing brightness, depending on the supply voltage. Dimmable LED lamps work with dimmer circuits like the one shown above.

The network dimmer regulates the supplied voltage. This means that at any voltage values, within the range specified by the manufacturer (it is indicated on the light bulb box), the lamp circuit will strive to maintain the specified current. Brightness in turn depends on current.

Regular LED lamps cannot be adjusted; at best, they will simply turn on and off; at worst, they will burn out at low values set on the dimmer.

The cheapest LED lamps have a quenching capacitor. Even if they are regulated, it will be only within very narrow limits, which means they are also not suitable. For an example of dimming conventional LED light bulbs, watch the video.

Dimmable LED lamps 220 Volt

Adjusting the brightness of 220V LED lamps is difficult because there is a current stabilization circuit installed on a specialized driver. Its task is to stabilize the output current to ensure a uniform and long-lasting glow of the LEDs, regardless of the supply voltage.

Conventional LED lamps are not very dimmable. To choose the right LED lamp for a dimmer, you need to carefully study the description and symbols indicated on the box and body of the light bulb.

LED lamps with dimming can be recognized by the inscription: “for dimmer”, “adjustable” or something similar; perhaps a conventional image of a dimmer will simply be drawn, as in the examples below.

Is it possible to adjust the brightness of LED lamps running on DC?

The photo shows a led dimmer for a 12V LED strip. Let's figure out how such a dimmer works with LED lamps.

For DC circuits, the operating principle of the regulator is different. Here, a bipolar or field-effect transistor, and as a dispenser – a pulse generator with a variable duty cycle.

The method of this control is called pulse width modulation (PWM). To understand how this works you need to look at the graphs.

Vcc is the voltage at the DC dimmer input, Vaverage is the output voltage. You can see how the average voltage changes. As the pulse duration increases and the pause length decreases (we increase the duty cycle), the output voltage increases.

Above is a circuit diagram of a “PWM dimming controller for LED lamps on NE555.” It can act as a device for dimming LEDs. It works like this:

NE555 is a timer, connected here in the pulse generator mode, the frequency and duration of which is set by an RC circuit consisting of R2, potentiometer R1 and capacitor C5, as in the previous circuit, the potentiometer regulates the charging rate of the capacitor, and the pulse width is formed in accordance with the charging speed.

Initially, the circuit produces symmetrical pulses, that is, the pause length is equal to the pulse length. But thanks to the presence of a potentiometer and a chain of two diodes VD1 and VD2, the capacitance is charged and recharged through different resistances of the potentiometer, or rather through different pairs of its contacts.

Therefore, PWM adjustable pulses are generated with a constant frequency, but a variable duty cycle.

If you use it in a car or for dimming an LED strip, you can eliminate the additional 9-volt power supply based on the 7809 linear regulator and supply power to the first point after it in the circuit.

But here are photos of a homemade dimmer for LEDs, if necessary, you can copy the location of the tracks and repeat it. Or assemble it on a breadboard.

A video of how dimming LED lamps works using this circuit, using a side-glow strip as an example, is located below.

Using this circuit, it is possible to dim 12V LED circuits and any other DC load. For example, adjust the speed of revolutions of a PC cooler, brushed motors, heaters, in general, anything you can think of. In one of the articles we already talked about.

What dimmer is needed for LED light bulbs?

To select a dimmer for LED lamps and ensure their compatibility, you must first decide which lamps you will use. If you are planning to buy 220V LED light bulbs, phase-pulse devices, which were discussed at the beginning of the article, are suitable for this. Take models with trailing edge cut-off.

For low voltage DC lamps (such as 12V, which are used in spotlights, table lighting or car lamps) - any PWM controller or dimmer is suitable for LED strips. They all work on the principle of pulse-width modulation; linear regulation is already a thing of the past.

It is also better to buy special LED lamps for dimmer. Although they are more expensive, there will be no problems with their adjustment. You will create the desired lighting solution only if you choose the right dimmer and LED lamps for it.

Share your experience in adjusting the brightness of LEDs and LED lamps in the comments!