Do-it-yourself dimmer with smooth switching on. Diagram for assembling a dimmer with your own hands and the assembly process

It is not difficult to adjust the brightness of the lighting in a room where a chandelier with several incandescent lamps is installed. We take a switch for several buttons and, if necessary, turn on or off some of the lamps.

Even if the chandelier is designed for one lamp, its brightness can be changed over a wide range by increasing or decreasing the supplied voltage. The LED works in a very narrow voltage range and when it drops, it simply goes out.

To change the brightness of LED lamps, a dimmer is used, which is a PWM controller (controller with pulse width modulation of power).

The principle of pole-width modulation (PWM)

Changes in the power supply voltage when using a PWM controller is ensured by supplying signals with a varying duty cycle to the switching element (in the case of LEDs - a field-effect transistor, triac or dinistor).

Bore (S) - the ratio between the duration of the pulses and the pause between them.

S \u003d T / T1, where T is the period of the pulses, T1 is the period of the positive edge.

In a PWM controller, the pulses follow with a constant frequency, only the duration of the pauses changes.

Below is a schematic diagram of a PWM controller:

Increasing the pulse width increases the time it takes for the current to flow through the transistor to the load, and hence the current to pass through. The pulse repetition rate is much higher than that which the eye is able to catch, usually 100-200 Hz, so we do not feel LED flickering. The advantage of load regulators based on PWM controllers is a significantly higher efficiency compared to resistive ones, since the excess load is extinguished, and not consumed.

Connecting a dimmer to the LED lamp power circuit

There are two connection options:

1. Connection diagram in front of the power driver when AC voltage is dimmed;
2. Connection after power driver, with PWM constant voltage regulation.

Industrial options for dimmers for LED lamps

Dimmer Control Type:

• Infrared;
• Radio;
• Stationary.

Controlled voltage:

• 220V.

Dimmer mounted instead of a switch, with a remote control. They are usually installed when converting ordinary lighting with incandescent lamps to LED strips.

Dimmer installed in front of the power driver LEDs on remote control with infrared control.

Sample with radio control... Unlike an infrared transmitter, such a remote control is able to turn on lighting even from the street.

Samples are produced with mechanical or touch control. There are even models that allow you to control the lighting using your smartphone via WiFi.

The main disadvantage of all devices is the rather high price.

If you have no desire to overpay for unnecessary functions, making a dimmer for 220v LED lamps with your own hands is not at all difficult.

Do-it-yourself dimmer assembly

Triac circuit:

In this circuit, the master oscillator is built on two triacs, a VS1 triac and a VS2 diak. After switching on the circuit, the capacitors begin to charge through the resistor chain. When the voltage across the capacitor reaches the opening voltage of the triac, current begins to flow through them, and the capacitor is discharged. The lower the resistance of the resistor, the faster the capacitor charges, the less the duty cycle of the pulses.

Changing the resistance of the variable resistor adjusts the gate depth over a wide range. This circuit can be used not only for LEDs, but also for any network load.

Connecting a dimmer as a switch

AC connection diagram:

The N555 microcircuit is an analog-digital timer. Its most important advantage is its ability to operate in a wide range of supply voltage. Ordinary microcircuits with TTL logic operate from 5V, and their logical unit is 2.4V. CMOS series are more high voltage.

But the generator circuit with the ability to change the duty cycle turns out to be quite cumbersome. Also, for microcircuits with standard logic, increasing the frequency reduces the voltage of the output signal, which does not make it possible to switch powerful field-effect transistors and is suitable only for low-power loads.

The timer on the N555 chip is ideal for PWM controllers, since it allows you to simultaneously adjust both the frequency and the duty cycle. The output voltage is about 70% of the supply voltage, due to which it can be controlled even by Mosfet field-effect transistors with a current of up to 9A. At an extremely low cost of the parts used, the assembly costs will be 40-50 rubles.

And this circuit will allow you to control a 220V load with a power of up to 30W:

The ICEA2A microcircuit after a little modification can be painlessly replaced with the less scarce N555. Difficulty may cause the need to self-wind the transformer. You can wind the windings on a regular W-shaped frame from an old burnt-out 50-100W transformer. The first winding is 100 turns of enameled wire with a diameter of 0.224mm. The second winding is 34 turns with a 0.75mm wire (the cross-sectional area can be reduced to 0.5mm), the third winding is 8 turns with a 0.224 - 0.3mm wire.

Dimmer on thyristors and dinistors

LED dimmer 220V with a load up to 2A:

This is a two-bridge half-wave circuit consisting of two mirror stages. Each half-wave of voltage passes through its own thyristor-dinistor chain. The duty cycle is regulated by a variable resistor and a capacitor.

When a certain charge on the capacitor is reached, it opens a dinistor through which current flows to the control thyristor. When the polarity of the half-wave changes, the process is repeated in the second chain.

Dimmer for LED strip

Dimmer circuit for LED strip on an integrated stabilizer of the KREN series.

In the classic circuit for connecting a voltage stabilizer, the stabilization value is set by a resistor connected to the control input. Adding a capacitor C2 and a variable resistor to the circuit turns the stabilizer into a kind of comparator.

The advantage of the circuit is that it combines both a power driver and a dimmer at once, so the connection does not require additional circuits. The disadvantage is that with a large number of LEDs on the stabilizer, there will be significant heat generation, which requires the installation of a powerful radiator.

How to connect a dimmer to an LED strip depends on the dimming task. Connecting in front of the LED power supply driver will allow you to adjust only the overall illumination, and if you assemble several dimmers for the LED with your own hands and install them on each section of the LED strip after the power supply, it will be possible to adjust the zone lighting.

"Dimmer" with a fixed level of brightness

Resistors nominal 100-500 kOhm, power 1-2 W.

It's not even a dimer, since there is no PWM controller here. But it is ideal for those who have picked up a soldering iron for the first time.

The ability to smoothly change the brightness of the incandescent lamp allows you not only to use lighting with great comfort, but also to save a significant share of electricity. All you need to do is connect the lamp through a small device called a dimmer.

The borrowed word "dimmer" (from the English dimm) suits this device perfectly, because in literal translation it means something like "extinguisher" or "dimming". What are modern dimmers and is it possible to assemble such a device on your own - this will be discussed below.

How is a dimmer for lighting lamps

Brightness controls - it is this term that is the Russian equivalent of the "dimmer" that migrated from the English language - they began to use it quite a long time ago. But in the original version, these devices could not provide any savings, since were an ordinary rheostat, well known to everyone who at least occasionally attended school physics lessons.

A rheostat is an "ancient" analog of a variable resistor. By increasing its resistance, we take away part of the power supplied to the lamp, but electricity is not saved at the same time, but simply turns into heat generated by the rheostat.

With the advent of semiconductor technology, fundamental changes have occurred in the device of dimmers, thanks to which these devices have become much more advanced. In modern regulators, the main role is assigned to two elements - a triac and a dinistor.

All kinds of dimmers produced by the industry can expand the functionality of almost any lighting fixture and increase their efficiency. But if the situation is not typical, for example, if small sizes are important, then only a home-made device can help.

Also, making can be a cheaper option than buying, which is very convincing. We will tell you how to assemble a dimmer with your own hands. The article presented by us describes in detail what components will be required, in what sequence to perform the work.

Factory dimmers are capable of delivering the expected economic result or to improve the comfort of living in all typical situations. In addition, their cost is different, which will allow you to make an affordable purchase.

But still, in a number of situations, you may not find a suitable option in size or power, so a homemade product may be the way out.

In most cases, the interested person will be able to purchase an inexpensive factory dimmer, the performance of which will satisfy him.

There are non-standard situations when industrial products do not meet human needs. For example, this happens if you need a small size, there is a desire to improve the aesthetic properties of its control panel.

Or a person considers it necessary to increase efficiency, make control more convenient, achieve any color effects, improve any other characteristic.

Making the simplest dimmer is not a difficult task, all the more you only need tools available to all, the main of which is a soldering iron

And you can also do the assembly yourself when you have the necessary components available, which will significantly reduce the cost of the procedure.

What you need to know about dimmers?

The verb "to dim" in english language means to become dim, to darken. This phenomenon is the essence of dimmers. In addition, a person additionally receives a number of additional benefits.

Pros of using the device

Among the advantages are the following additional features:

• reduce energy consumption - this leads to greater efficiency;
• replace several types of lighting fixtures - for example, one lamp can perform the functions of a night floor lamp, main lighting, etc.

In addition, the user can get various lighting effects, for example, use ordinary lighting controlled by a dimmer as a light music.

And also its functionality allows you to work in conjunction with security systems or simply simulate the presence of people in the room. That will help the owners of any premises to protect their property from intruders or even prevent their unauthorized entry into an apartment or office.

The basis of the dimmer design is a triac. It is important to remember that its power should be 20-50% higher than the same load indicator. In addition, it must be able to withstand 400 V. This will ensure durability of the product.

Additionally, the dimmer is able to make the control of light sources and other electrical appliances more convenient and efficient. For example, you can use radio or infrared signals, which will allow you to perform the necessary manipulations remotely.

Or it is possible to use multiple lighting control points instead of just one. For example, if the user wants to make the lighting in the bedroom more modern, then the controls can be installed at the entrance there, as well as near the bed.

Such a decision will make the life of the owners somewhat more comfortable. You can do the same in any other room.

How is regulation done?

If an interested person decided to assemble a dimmer on their own, then the procedure should be started not with thinking about how to do it, but with defining goals and tasks that will be solved.

This is how an ordinary sinusoidal current looks like, and the essence of dimming is to "cut" it. This will shorten the pulse duration and enable the appliance to operate at less than full power.

So before proceeding with the assembly, it is necessary to decide what type of lamps will be used. This procedure is mandatory because there are different principles for controlling the brightness of the glow.

These include:

• voltage change - this method will be relevant when using outdated incandescent lamps;
• pulse width modulation - this option must be used to control the brightness of modern energy-saving lighting fixtures.

Changing the voltage of LED lamps is ineffective due to the fact that they work in a narrow range and, with a slight deviation from the norm, they simply go out or do not turn on. That will not allow you to reach your full potential conventional devices, therefore they produce specialized ones.

In addition, the use of simple but outdated rheostats does not provide an opportunity to save on electricity. After all, excess electricity in the form of heat simply dissipates in the air.

A properly made dimmer should provide just such a sinusoid in which short pulses alternate with long pauses. Moreover, the longer it is, and the signal strength is less, the dimmer the lamp will glow.

With the help of pulse-width modulation, it will be possible to assemble a dimmer, which provides the lamps with the ability to work at 10-100% of their power. In this case, the user will receive a pleasant bonus in the form of saved energy.

And you can also take full advantage of all the other advantages of dimmers, including durability.

Relative simplicity of design

Despite the fact that household dimmers provide a noticeable visual and economic effect, they are distinguished by a simple device.

That ensures a long service life, and in the case when a person decides to perform self-assembly, then the simplicity of this operation. As a result, almost anyone can cope with it, even without special knowledge.

A homemade dimmer can be used in different areas, but it should be borne in mind that its manufacture on one soldering of components will not end. Since the homemade product will need to give an attractive appearance

So, the most popular modern dimmers are created on the basis of just a few elements:

• dinistor, its other name is often found - diac;
• triac, in other words - triac;
• pulse shaping unit.

In addition, the structure requires the presence of several minor parts, without which work is impossible. These include capacitors, resistors (DC, AC). Each of the main semiconductor devices listed do their part of the job of controlling the brightness of the lamps.

A triac is often compared to a door for electricity, and it can be entered in both directions. That is, it is possible to pass current to the lamps in an unlimited amount, but, if necessary, return its surplus back.

The implementation of such a process provides an anode with a cathode. They swap places depending on the direction of movement of electricity. In addition, a multilayer conductor design is provided, which allows you to perform tasks as accurately as possible.

The direction switching itself is performed by a dinistor, which is a bi-directional diode.

Circuit complication factors

A person who wants to assemble a dimmer on their own should think not only about purchasing the necessary semiconductors. Since the design will need to be capable of handling, positioning, and even aesthetics, there are a number of issues to consider.

These include:

• type of management;
• method of placement;
• appearance.

Since the listed items significantly affect the performance of the dimmer, each of them should be dealt with separately. That will allow you to cope with the work efficiently.

Existing types of device control

Since the dimmer needs to be controlled, the person should choose the best option. Because there are many of them and each has its own characteristics, advantages and disadvantages. This will significantly affect the design.

Manipulations can be performed in any of the following ways:

• mechanical;
• electronic;
• remote.

But most often the first option is used for all kinds of homemade dimmers. Since mechanical control is the easiest to assemble, and when buying components you will have to pay the least.

The dimmer circuit makes it possible to understand how it works. Namely, when a current appears in the network, it, passing through the resistors and one of the built-in diodes, charges the capacitor. The excess voltage from which enters the dinistor and triac. The load transmitted to the lamps depends on its position.

In this case, a person only needs a regulator, which can be a pivot arm. If desired, it can be replaced with a pressure element. In this case, all manipulations will be performed with ordinary keys familiar from traditional switches.

Combined rotary-push devices are often used. They enable the on / off operation to be performed with the keys, and the adjustment itself - with the rotary lever. Which many users find convenient.

Any of the above options can be similar in size and appearance to a conventional switch, which will allow you to replace such a device. This is another advantage. Electronic control implies the use of sensors to perform all the necessary manipulations. They are also in the form of traditional switches and can be easily replaced.

Sensors have a significant advantage over mechanical counterparts in the form of a modern appearance. The other side of the coin will be the higher cost of components. Remote control is the most comfortable, convenient, it is performed using conventional remote controls.

There are different types of command signal transmission:

• radio signal;
• infrared signal.

In the first case, the user will be able to carry out the necessary adjustments from anywhere in the building, premises and even from outside them. Which is convenient, effective, but the components will cost more than buying a remote control with an infrared signal.

The signal is capable of transmitting the necessary information only when hovering over itself. And this can be done only within one room.

A simpler is the hinged version of the dimmer assembly. And the most durable is a printed circuit board, which will prevent many types of early breakdown.

Nevertheless, this feature is usually not considered a disadvantage, therefore more affordable kits with an infrared signal are more popular. An acoustic one also belongs to remote control methods, but in this case, you will have to purchase a sensor capable of picking up sound commands: claps, music and other similar noises.

Still, you should know that the latter option is more effective than effective. Since any third-party sounds, for example, barking of a pet, loud conversation will lead to an unauthorized change in the brightness of the lamps. This won't always make users happy.

At the same time, an acoustic sensor built into the dimmer design can make any party unforgettable, as it makes the lighting fixtures respond to changes in the volume of the music. That is, thus, it is quite possible to replace light and music.

In addition, you should be aware that control options using a computer with a wired or wireless connection, as well as a smartphone, tablet, which transmit the desired command signal via Wi-Fi, are becoming more and more popular.

Printed circuit boards are compact and durable compared to a hinged circuit. In addition, they are safer, which is important, since dimmers are used in rooms where people are.

To be able to use any of the listed methods, the dimmer structure must be equipped with the necessary elements. Which makes it more difficult, therefore more expensive. As a result, the most demanded control option is traditionally mechanical.

Device placement type

Any modern dimmer can be placed in just three ways, and in everyday life it is used less in total - only 2. One option is rarely in demand due to its structural complexity and performance.

Therefore, the following types of accommodation are used for housing or small commercial premises:

• waybills;
• built-in.

In the first case, a traditional switch is replaced with a dimmer, in the second, it is installed out of sight, that is, it is mounted in a transfer case, a specially made niche. This means that in one situation a person needs to take care of a control panel with high aesthetic qualities.

And in another, this nuance does not play any role. Since the device will be hidden from the eyes. But you will have to use only the remote control method. Overheads are mainly mechanical or electronic varieties.

How the dimmer works

The most effective way to control the brightness is using pulse width modulation. Since it is most suitable for modern.

The principle of operation in this case is the supply of current in short pulses, between which a long pause is maintained. Moreover, the longer its duration, the lower the brightness of the glow.

Connecting regulators is an important stage in the assembly, since functionality and comfort depend on it, in fact, for which people do this work.

At the same time, the simplest devices are able to change the characteristics of the light by the usual decrease / increase in the applied voltage. But this option will only be beneficial when using incandescent lamps.

In the case of using LED devices in tandem with the device, they will only be able to work, since ordinary LEDs are not adjustable.

Handmade dimmer making

Initially, it is necessary to decide on a number of parameters, including power, type of placement, control. Without this procedure, it will be possible to create an efficient regulator only by chance, which is rare.

In addition, you will need a capacitor and 2 resistors capable of supporting the previously determined power. Moreover, one of them must be variable. This feature will allow you to change the voltage.

The diagram shows how a user can control one light source using two controls installed in different parts of the room, which is convenient

And when its value reaches the maximum possible for the used dinistor, then it is triggered and gives the necessary command impulse. Which is sent to the triac, and then goes to lamps or other electrical appliances.

When this power switch opens depends on the position of the controls. Since it can be 220 V and 40 V, if a person needs it.

Since craftsmen mainly make overhead dimmers, it will not be difficult to install it in a chain. Since this operation is no different from the installation of a traditional switch

All of the above structural elements are connected into one product according to the attached diagram using wires and soldering. Contacts must be carefully isolated. Since a short circuit is one of several common causes of electrical equipment failure.

Connecting the dimer to the circuit

This is no less important part of the work than the manufacturing itself, since the durability of operation largely depends on the quality. In addition, the connection affects the convenience and comfort of control, so dimmers are usually divided according to this characteristic.

They are as follows:

• by the type of switch - they replace traditional switches and regulate one lamp or a group of them, for example, a chandelier with a large number of lighting elements;
• walk-throughs - allow you to control one electrical appliance, for example, an LED lamp, using several controls, located for convenience in different parts of the room, building.

In the first case, when using a network that includes 3 wires, zero and ground go to the lamp, another electrical appliance, and the phase to break. That is, the procedure is familiar to everyone who replaced conventional switches.

When checking the regulator, its installation and operation, a person should observe safety measures, since sufficient voltage passes through it to cause harm to health

When installing two pass-through dimmers from the junction box, three wires should be connected to each of them. This is a prerequisite. Then the first two pins are used to connect both regulators. A jumper should be used to ensure reliability.

Another of the free contacts is connected to the phase, and the last to the lighting fixture. After that, the connection is checked for operability.

During these operations, you should remember to observe safety measures - each of them can only be performed after a power failure.

With the guidelines for choosing a dimmer for controlling an LED strip, he will introduce, completely devoted to this interesting topic.

Conclusions and useful video on the topic

The first video will allow you to quickly understand the manufacturing procedure:

The following video material will allow you to get acquainted with the principle of operation of modern dimmers:

Any user, even without special skills, will be able to figure out how to correctly make a simple dimmer with their own hands. This is a completely inexpensive and uncomplicated solution. The main thing is to select the elements of the required power and connect them to each other in a quality manner.

At the same time, it will be necessary to give the product a decent appearance, which complicates the task. But for this purpose, you can use industrial regulator housings, even used ones.

Dimmer is a newfangled name for a device, which is often referred to as a dimmer in our country and is intended for smooth control of the power of electrical appliances, primarily lamps (in English, "dim" means "dim"). The thing on the farm is very useful, but it is not at all necessary to buy it. In the sense that anyone who has ever held a soldering iron in their hands can make such a device with their own hands. Below we will explain how this is done.

The simplest type of dimmers can be considered any variable resistor, for example, a rheostat known to everyone since school. If you turn it on in series with an incandescent lamp, then when you change the position of the slider, its brightness will change. However, it is extremely unprofitable to use such a dimmer, since it does not reduce the power consumption, but only "pulls" part of it towards itself, turning it into heat.

General view of the dimmer

A practical option for a dimmer is an autotransformer. The secondary winding of this device has several pairs of terminals, on which different output voltages are formed. When the load is connected to a particular pair, it will work with different power.

Dimmers based on autotransformers have several advantages:

• consume from the supply network only the power that is currently needed;
• regardless of the ratio of the input and output voltages, they give a sinusoidal current at the output with practically no distortion;
• do not interfere.

But such devices are relatively large in size and weight, and for adjustment, mechanical switches have to be used, so they are used today only in rare cases.

By now, electronic dimmers assembled on semiconductor elements have become popular. These are compact, weightless devices.

How the electronic dimmer works

Power regulation does not consist in voltage conversion, as is the case with a transformer: the dimmer passes current only at a certain (voltage) value. Recall that the voltage in the AC network constantly fluctuates in a sinusoidal manner from -230 V to + 230 V.

Factory-made electronic dimmer

That is, an electronic dimmer is a high-frequency switch that has time to turn on and off during each half-cycle of the alternating current. Thus, the load is not connected to the network all the time, but only for a certain fraction of a half-period, due to which the average voltage and power of the electric current decreases.

It is obvious that the current at the output of the electronic dimmer has a far from sinusoidal characteristic: it is rather a kind of alternating-pulsating version of it. If you plot the graph, part of each wave of the sinusoid will be clipped, as it were.

It is important to know that this type of food is not suitable for all appliances. In those that require a current with a low harmonic distortion, the winding may overheat, as a result of which the device will fail.

Among household consumers, this category primarily includes:

• electric motors;
• appliances with impulse unit food;
• devices with transformer power supply: televisions, radios, fluorescent lamps with electronic ballast;
• induction transformers for halogen lamps.

But all that has been said applies only to the simplest electronic dimmers with a classic circuit. More sophisticated dimmers, which by now have not only been developed, but also mass-produced, are "omnivorous" - they can be connected to any load. The main thing is to choose the right model.

Electronic dimmers have one more drawback: in their simplest design (such models are the cheapest) they are a source of tangible electromagnetic interference both in the radio frequency range and in the wires connected to them. In the room where the dimmer is installed, it may be difficult to listen to the radio receiver, there may be disturbances in the operation of the measuring equipment, as well as the sound recording - in the form of a background.

There is a way to eliminate it - you need to improve the scheme by adding a filter to it. In this capacity, chokes are used, they can be supplemented with capacitors (inductive-capacitive filter). Dimmers with filters are somewhat more expensive.

An incandescent lamp, to which a voltage reduced by an electronic dimmer is applied, emits a hissing sound, barely audible, but clearly visible in complete silence. The more powerful the lamp, the more intense the whistle will be. The fact is that a kind of current obtained at the output of the dimmer causes mechanical vibrations in the filament, which lead to the appearance of such a sound.

This phenomenon is called magnetostriction. It also takes place when connected directly, that is, without a dimmer, but in this case it manifests itself to a much lesser extent, and does not produce sounds audible to a person.

How to make a device with your own hands

A conventional dimmer is simple and cheap to manufacture, as it requires a small number of readily available radio components. Here are the main ones:

A few words should be said about the assembly of the dimmer. The simplest is the so-called surface-mounted installation, when all elements are connected into a single circuit by means of wires.

This is what a hinged dimmer looks like.

Before soldering, the stripped conductors of a piece of wire cut to the required length, as well as the "legs" of radio components, must be tinned with a soldering iron (solder and special flux or rosin are used).

Solder wire connection materials

After soldering, all connections should be wrapped with electrical tape. If this is not done, a short circuit may occur due to careless contact or moisture ingress.

A more difficult option is to assemble a dimmer on a homemade printed circuit board.

Assembling a dimmer on a PCB

Making it requires some skill, but the device will turn out to be miniature and more reliable. The tracks on the board, as well as the wire cores for surface mounting, must be tinned. The soldering process is also no different.

Now let's take a look at several electronic dimmer circuits.

On a triac

This device is designed to be connected to a network with a voltage of 220 V. As you can see, in addition to a triac and a dinistor, there is an RC chain here. It has a voltage divider consisting of a variable resistor R1 and a constant R2.

Dimmer circuit on a triac

The circuit works as follows:

1. The user sets the resistance R1, on which the voltage in the circuit R2 - C1 depends. This voltage, in turn, determines the charging time of the capacitor C1.
2. When the voltage across it reaches a certain value, it forces the DB3 dynistor to open, which is included in the same circuit between R2 and C1.
3. At the same time, a pulse is applied to the VS1 triac through DB3, which opens and passes current to the load. The faster C1 is charged, the earlier VS1 will open and, accordingly, the longer will be that part of the half-cycle during which the current is passed to the load. Consequently, the electrical power will also be greater.

The process of adjusting the light intensity with such a dimmer is shown in the graph:

Lighting intensity control schedule

The time it takes for the charge in C1 to reach the opening threshold of DB3 is denoted by t *.

On thyristors

The good thing about thyristors is that they can be removed from old electrical appliances such as televisions. Thus, the dimmer is practically free. Here is its diagram:

Thyristor dimmer circuit

Thyristors, unlike triacs, pass current in only one direction, so for this dimmer you will need two of them - one for each half-wave of the alternating current. Accordingly, you will need two dinistors, through which, as in the first circuit, a control pulse is formed.

In principle, the scheme is very similar to the previous one:

1. The positive half-wave through the R5 - R4 - R3 circuit charges the capacitor C1.
2. As soon as the voltage on C1 is sufficient to open the V3 dynistor, it (dynistor) will pass a control pulse to the thyristor electrode V
3. V1 will open and let current into the load.
4. With a negative half-wave, thyristor V2 will operate in the same way, while V1 will be closed. The capacitor is charged in this case through the circuit R1 - R2 - R

Condenser dimmer

Unlike the first two, this version of the dimmer allows you to reduce the power only by a certain fixed amount, that is, an intermediate stage of luminaire brightness appears. But it is very compact.

Condenser dimmer

The principle of operation is extremely simple. As you know, an alternating current can flow through the circuit in which the capacitor is connected, but its power will depend on the capacitance of the capacitor. The faster it charges (small capacity), the smaller the fraction of the half-wave will have time to pass through the circuit. And vice versa - with a large capacity, even the entire half-wave can do useful work.

Therefore, you need to select a capacitor with the required capacity and connect it to the circuit so that you can direct current either through it (reduced power) or bypassing (100 percent power).

You can include another capacitor in the circuit with the ability to switch between it and the first capacitor (a 4-position switch is required). Then an additional power adjustment step will appear.

Capacitors can be used paper, non-polar, abundant in old electrical appliances. Their capacity is selected according to the following table:

Capacitance-voltage parameter table

On a chip

Now we will consider a dimmer for direct current with a voltage of 12 V. Such a regulator is most conveniently assembled on a KREN microcircuit - an integral stabilizer.

Dimmer circuit on a microcircuit

Due to the use of a microcircuit, the design of the device is extremely simplified, respectively, the amount of assembly work becomes minimal. In addition, such dimmers have a protection function.

To adjust the power, as in the first two schemes, a variable resistor is used (R2 in the diagram). The value of the reference voltage at the control electrode KREN depends on its resistance, on which, in turn, the output voltage depends. The adjustment range is very wide - from 12 V (100%) to a few tenths.

It should be noted that the KREN microcircuit heats up quite a lot, which is why it has to be equipped with a relatively large radiator. To a much lesser extent, this drawback is manifested in dimmers assembled on the basis of an integral 555 timer and a KT819G transistor controlled by it (it plays the role of an electronic switch like a thyristor and a triac).

The control signal is short PWM pulses that switch the transistor to either fully open or fully closed, so that the voltage drop across it is the smallest possible. Accordingly, the scheme turns out to be more economical than on the basis of KREN, and due to the use of a radiator of smaller dimensions, it is also more compact.

Choosing a ready-made dimmer

If you decide to purchase a factory-made dimmer, pay attention to the following:

Specifications

There are only two of them:

• mains voltage;
• permissible load power.

For example, for a chandelier with three conventional 100 W incandescent lamps, a 230 V / (25 - 400 W) dimmer is suitable. The permissible power is always indicated in the form of a certain range, the upper value of which should be taken with some margin.

Note! Some Chinese dimmers, for example, from the Powerman company, have an interesting feature: one power value is indicated on the label, and another is indicated on the device case. Moreover, these values \u200b\u200bcan be quite different, for example, they write "600 W" on the label, and "25 - 400 W" on the case.

Therefore, when buying a cheap imported dimmer, do not limit yourself to studying the information given on the box - be sure to consider the device itself.

Load type

The simplest dimmers are designed to control the power of incandescent and halogen lamps.

Rotary dimmer for incandescent lamps

More advanced models can also work with low-power electric motors - usually fans are connected through them. An example is the Kopp Dimmat dimmer (Germany).

One of the representatives of the Kopp Dimmat range of dimmers

Dimmers are also available through which you can connect fluorescent lamps. If any of the mentioned loads are powered through a simple dimmer, then it may fail.

It is important to know that to the dimmer intended for connection, for example, fluorescent lamps, you can connect not every such lamp. It should be marked "dimmable" or, equivalently, "dimable".

Control method

On this basis, dimmers are divided into several types:

Mechanically controlled

These are the simplest and cheapest devices. They have a rotary handle, which is why they are usually called that - rotary. As an example, we can cite the domestic model "Bella C16-65". Rotary dimmers have minimal functionality. To turn off the light, the handle must be turned to the extreme position until it clicks; to turn it on, it must be turned in the other direction by a certain angle, on which the brightness of the lighting will depend. The inconvenience of this control method lies in the absence of a function for memorizing settings - the brightness of the lighting has to be adjusted again each time it is turned on.

Electronically controlled

These dimmers are divided into key and touch controls. There are also pseudo-sensory ones, for example, the Simon 75305–39 model, the keys of which are pressed with so little effort that they hardly differ from the touch panel.

Touch dimmer for LED lamps

Usually, keys and touchpads have a double effect: with a short press / touch, the light turns on or off, with a long hold, the brightness of the lighting changes. When the lamp is turned on, the brightness will immediately be the same as it was set before it was turned off, that is, there is no need to adjust the light again every time.

Note! Along with the usual dimmers are produced, which, when the lamp is turned on, apply voltage to it with a smooth build-up. These dimmers are believed to extend the life of the lamps.

An example of a touch control dimmer is the SM180 model from Eunea Merlin Gerin (Spain). In addition to conventional luminaires (incandescent and 230 V halogen lamps), low-voltage halogen lamps with a conventional (ferromagnetic) transformer can be connected via this regulator.

Remote controlled

Control signals can be transmitted using both infrared (IR) radiation and radio frequency. For example, the Smart Dimmer Pro 21 of the French company Legrand is equipped with an IR receiver.

Model Smart Dimmer Pro 21

You can connect to it:

• low-voltage halogen lamps not only with conventional, but also with electronic transformers;
• fluorescent lamps with electronic ballasts.

The ability to work with such loads is due to the presence of a phase cut-off switch on the leading / trailing edge.

The total power is up to 500 W.

The remote control can be used not only proprietary, but also any other with support for the RC5 code.

Sound controlled

These devices can respond to pops or even voice commands.

This material will help to independently connect the cotton switch:

Options

Many of today's dimmers are equipped with an additional terminal to which conventional pushbutton switches can be connected. With their help, you can control the lighting in the room from several places.

There are models equipped with a timer, for example, the already mentioned pseudo-sensor dimmer Simon 75305–39.

Pseudo-sensor dimmer Simon 75305–39

After the time set by the user, the device will automatically turn off the light.

The widest range of possibilities is provided by programmable dimmers equipped with a microcontroller. They can have such functions:

• imitation of the presence of residents (automatic switching on and off of the light in order to mislead the thieves watching the windows);
• brightness control in various modes, for example, blinking with a certain frequency (Strobe);
• control of several groups of luminaires (zones) and storing different lighting scenes for them.

An illustrative example of a programmable dimmer is the Lutron Grafik EyE system (USA).

Dimmer Lutron Grafik EyE

This is how its multi-zone manifests itself: the user can connect several groups (up to 6) to the system, for example, a chandelier, wall lamps and decorative lights, and then set some brightness value for them for different occasions.

For example, when a family gathers at a holiday table, the brightness of the chandelier is set to 70%, and the brightness of wall and decorative lights is set to 20%. To watch TV, another scene is set up: the brightness of the chandelier is reduced to 20%, the brightness of other lamps is increased to 30%.

The settings for all lighting scenes (their maximum number is 16) are stored in the system memory, so you can easily switch between them - both quickly and smoothly (the process of transition from one scene to another can be extended for an hour).

The Grafik EYE system can be operated with a remote control, it can only work with incandescent lamps.

The maximum total load power is 2300 W, while the maximum for each zone is also negotiated - no more than 800 W. The capabilities of the system can be expanded by connecting a power amplifier to it. Then the limit for each zone will increase to 1800 W.

Programmable dimmers are also produced in the CIS countries. For example, the Sapphire 2503 model of the Belarusian company Nootekhnika supports the presence simulation mode and has a timer that turns off the lighting 12 hours after the last user action. The dimmer has a touch panel and can be controlled by a remote control. When switched on, the current is supplied to the load on an increasing basis (which prolongs the life of the lamps).

Carefully study the product passport. Some dimmers get noticeably hot, so manufacturers recommend using them with restrictions. So, for example, the Dimmat dimmer of the German company Kopp is not recommended to be switched on with a load of more than 300 W if the room temperature exceeds + 25C: after all, the maximum permissible power declared in its characteristics is 400 W.

These requirements should be treated with special attention if the wall on which the device is supposed to be fixed is made of materials with low thermal conductivity, such as wood or drywall.

You should be aware that the efficiency of a light bulb "screwed" with a dimmer is greatly reduced. Therefore, in the event that you have to operate the lamp in the mode of reduced brightness most of the time, it is more expedient to replace it with a less powerful one and use the latter without a dimmer.

The most "tenacious" are domestic rotary dimmers. So, for example, the already mentioned model "Bella S16-65" is capable of operating at voltage surges from 60 to 285 V.

All modern dimmers have a fuse, so it makes sense to purchase at least one spare beforehand.

Note! When the power of a low-inertia light source, for example, an LED strip or a gas-discharge lamp, is reduced with the help of a stroboscopic effect occurs. Moving or rotating machinery and tools can appear stationary in this kind of lighting, which can be very traumatic. Therefore, dimmers should be used with caution in workshops and production areas.

How to connect a dimmer

In general, the dimmer is connected like a conventional switch, but there is a condition: the regulator must be switched on only in the phase gap (the switches can be set both in phase and in "zero").

In practice, dimmers are often installed in pairs or with switches.

The dimmers are connected like switches. Both of these elements are mounted in series with the load. The dimmer can be safely put in place of a conventional switch. To do this, you need to disable mains supply, disconnect the wires from the terminals of the old switch, and install a dimmer in its place. This operation is further simplified by the fact that the installation dimensions of the dimmers correspond to the dimensions of simple switches.

Dimmer connection schematic diagram

When connecting a dimmer in the mains, remember: it must be included in the gap of the phase (L), and not the neutral (N) wire.

Circuit with switch

Such schemes are extremely convenient: they allow you to control the intensity of lighting from anywhere in the apartment. In the bedroom. For example, it is advisable to install a dimmer next to the bed - in this case, the user does not have to leave the warm bed in order to decrease or increase the light intensity.

Dimmer wiring diagram with switch

This scheme is appropriate to use in smart home systems. Effective light control allows you to highlight specific areas of a room or interior details. A simple switch is installed near the interior door. It is used when entering and leaving a room - when you need to turn on or off the light.

Installation diagram with two dimmers

If necessary, you can provide adjustment of the intensity of light from two points. in this case, two dimmers are installed, and their first and second terminals are interconnected. A phase wire is connected to the third terminal of any of the dimmers.

Connection diagram with two dimmers

The wire to the load comes from the third terminal of the remaining dimmer. As a result of such manipulations, three wires should come out of the junction box of each of the dimmers.

Dimmer activation with two pass-through switches

The principle of operation of this scheme is as follows: one switch is installed at the entrance to the room, the second at the other end of the staircase or corridor. In this case, the dimmer is mounted between the switch and the load in the phase conductor.

Dimmer wiring diagram with two pass-through switches

A dimmer must not be installed between the pass-through switches.

Please note: if the dimmer in this circuit is off, none of the pass-through switches will work.

Connecting a dimmer to LED strips and lamps

If you connect a dimmer to the LED strip, it will be possible to change the brightness of its glow. A dimmer is chosen according to the total power of the LED strips.

When implementing this scheme with single-color tapes with a dimmer, the power supply is connected. The dimmer leads are connected to the load itself, while observing the polarity of the current.

In the case of using LED strips with RGB channels, the dimmer is also connected to the power supply, and its outputs to the signal controller.

The power of the dimmer in any of the above cases should exceed the calculated power consumption of the tapes by 20-30%.

Please note: to work with lED lamps and special dimmers are available with ribbons.

Video: how to replace the switch with a dimmer

Dimmers are very popular, and this encourages manufacturers to actively develop this industry of instrumentation. By now, we have learned how to make regulators for any type of load, including those with transformer power supplies. But if we talk about ordinary incandescent or halogen lamps for 220 V, then a dimmer for them is an extremely simple device and, as the reader could see, it is quite easy to do it yourself.