/ / Dimmer: scheme, connection, reviews. Dimmer - what is it?

Dimmer: scheme, connection, reviews. Dimmer - what is it?

Люди используют помещения для различных целей, и These features require different light levels. It is convenient to adjust it with a dimmer - an electronic device that allows you to change the level of illumination from "almost dark" to full visibility by simply turning the knob or sliding the lever.

Why do we need dimmers?

Illumination of rooms in the house is very important.The level in each room dictates what you can and cannot do, and this has a huge impact on your feelings. For example, you can not read under one lit candle, but a romantic dinner for two will not seem so pleasant under a 1.5-kilowatt halogen lamp.

Modern dimmers, such as the Legrand dimmer, allow you to smoothly adjust the luminance of luminaires with lamps of various types.

dimmer what is it

Resistor dimmers

Initially, to adjust the level of light usedA fairly simple solution is a variable resistor, included as a dimmer. What did it do? A conventional wire resistor is a thin conductor that creates a certain (in accordance with the rating) resistance to the movement of electric charges. In the design of a variable resistor, in addition to a resistive material and two fixed contacts, there was also added a movable contact with its output. Such element is connected to electrocircuits by mobile and one of motionless contacts.

In this design the total variesresistance of the resistor by adjusting the distance that the charge must pass through the resistive material, and simply speaking - the length of the wire from the fixed to the moving contact. If the moving contact is located near a stationary (connected to the circuit), then the resistance of the resistor is minimal. If it is displaced to the second fixed contact, the charge must pass through all the resistive material.

dimmer legrand

When the charge moves under the actionelectrical forces through a resistor, its energy is lost in the form of heat. If you put a resistor in a series circuit, then the energy loss in it causes a corresponding voltage drop across the resistor, reducing the energy available for other loads (light bulbs, for example). Reducing the voltage on the bulb lowers its light output.

Проблемой в этом решении является то, что вы в you end up spending a lot of energy on heating a resistor that doesn’t light up the room but costs a lot of money. In addition to energy inefficiency, resistor dimmers are usually cumbersome and potentially fire hazardous, since the variable resistor generates a significant amount of heat. Modern devices use a more efficient approach.

Principle of operation

So, actually dimmer.What does this mean in terms of differences from the resistor? Instead of taking energy from the bulb in a variable resistance, modern dimmers in each period of the current change briefly block the path for its passage in order to reduce the total amount of energy dissipated throughout the circuit. It turns out that the current in the light bulb turns off many times a second.

The switching cycle is built around a periodfluctuations in household AC. They have a different voltage polarity - in a hilly sinusoidal current wave, it ranges from a positive maximum to a negative one. In other words, a moving charge, which constitutes an alternating current, constantly changes its direction of movement. In Russia, it goes through one cycle of change (movement of charges in one direction, then the other) 50 times per second.

"Break" sinusoid current in each of its half-period -that's what dimmer does. What does it mean? It automatically turns off the circuit of the bulb each time the current changes direction, that is, when there is zero voltage in the circuit. This happens twice per cycle, or 100 times per second. The supply of current to the luminaire circuit is switched on again when the voltage rises to a certain level.

This principle - "include by level" - setsthe position of its handle switch with dimmer. If it is set to a light environment, it turns on very quickly after turning it off. The circuit is turned on for most of the cycle, so that it delivers more energy per second to the light bulb. If the dimmer is set to a lower illumination, it will wait longer after turning it off until it turns on again at the end of the cycle.

remote dimmer

This is a basic concept, but how does a dimmer actually work? The wiring diagram presented in the next section will answer this question.

Electronic dimmer device

We already know that he quickly turns off the light inchains to reduce the energy supplied to the lamp. And yet, specifically the dimmer itself - what is it? The central element of its circuit is an AC semiconductor switch, or triac.

Triac is a small semiconductordevice similar to a diode or transistor. Like them, the triac consists of different layers of semiconductor material. These include n-type materials, which have many free electrons, and p-type materials, which have many “holes” through which free electrons can pass.

Triac able to pass current at differentthe polarity of the voltage applied to it, i.e., in both half-periods of the alternating voltage of the network, but only if some control voltage is applied to the third electrode, the gate. This is how the dimmer works. The diagram below shows how it is turned on.

dimmer circuit

The voltage on the gate of the triac, whichIt is necessary for its opening, it is supplied from the storage capacitor, and the time of its charge from the beginning of the half-period of the supply voltage is controlled by the variable resistor. So what happens in this circuit? In a nutshell:

  • The triac acts as a supply voltage switch.
  • The voltage on the gate controls the time of its inclusion.
  • Variable resistor sets the voltage at the gate.
  • A choke serves to smooth the shape of the current in the lamp power supply circuit (see the next section).
  • The interference suppression capacitor prevents radio interference from the dimmer circuit.

Connecting to the network

It should be noted that constructively allThe radio elements shown in the diagram above are mounted in the housing of the dimmer, which has only two terminals for switching the device into a single-phase electrical network. Therefore, from the point of view of technology for making such a connection, a dimmer is completely analogous to a conventional two-pole switch. By the way, some of their designs have such a built-in switch, turned on at the input of the whole circuit, and its key is located next to the adjustment knob. Therefore, connecting a dimmer, as in the case of a conventional switch, follow these steps:

  1. Identify a luminaire or a group of luminaires to control from the dimmer.
  2. Calculate the current consumed by the lighting devices when powering them without a dimmer.
  3. Choose a dimmer with a maximum long operating current of not less than that obtained in Section 2.
  4. Set the dimmer to the right place andConnect to the network, just like a regular bipolar switch. Remember at the same time that any switch should be installed in the gap of the phase wire, not the “zero” wire, i.e. it should be in the current path to the luminaire (group), and not after it.

Real dimmer circuits are much more complicated.So, there may be a remote dimmer with a remote control, switched off (automatically) by a timer, connected to the “Smart Home” complex, as well as with acoustic or voice controls. However, all this "smart stuffing" is hidden inside the device, and the process of connecting it to the network does not complicate at all.

Humming lamps with dimmers

According to reviews of some users, when connectinginstead of a cheap dimmer switch, a strange humming sound is heard in the power circuit of the incandescent lamp. This is due to fluctuations in the filament lamp caused by a change in the shape of the current coming from the triac.

As you know, the current flowing through the wiresgenerates a significant magnetic field strength, and current oscillations cause a pulsating magnetic field. The filament in a light bulb is simply a wire helix, which, like a solenoid, is magnetized by a current passing through it, and its magnetic field oscillates at an alternating current frequency.

Normal sinusoidal alternating currentoscillates gradually, like its magnetic field. The current from the dimmer changes abruptly when the triac becomes conductive. This sudden change in current changes the magnetic field dramatically, which can cause the filament to vibrate. In addition to producing a soft buzzing sound, a rapidly changing magnetic field will generate weak radio signals that can interfere with nearby TVs or radios!

Top dimmers contain additional components.to destroy the buzzing effect. As a rule, the dimmer connection circuit includes an inductive choke (see diagram above), which is a long wire wrapped around an iron core, and an additional interference suppression capacitor. Both devices can temporarily store electricity (in the form of magnetic field energy, current and energy of electric charges) and use it later. This energy smoothes sharp voltage surges caused by triac switching to reduce hum and radio interference.

led dimmer

Dimmers and lamps

Светорегуляторы создают атмосферу комфорта в housing and reduce energy costs. However, not all bulbs are compatible with them, and this can create difficulties for homeowners. Many consumers publish negative reviews about the dimmer regulation of light, but the analysis of such responses leads to the conclusion that their authors are simply not familiar with the principles of compatibility of light bulbs and dimmers among themselves.

Light bulbs are characterized by power and voltage.With the wrong choice of dimmer, some of their types get the wrong voltage for them and create problems. Therefore, when choosing lamps for dimmers, people should be aware of their different types and learn to choose only compatible with their dimmers.

dimmer switch

Consumers can choose incandescent bulbs,halogen, fluorescent and LED lamps. The first two types of lamps are easy to control with dimmers, while fluorescent and LED lamps with greater light output are more expensive and work worse with the devices in question.

Incandescent lamps

Incandescent lamp works becauseelectric current passes through its filament, which heats up and begins to glow. These bulbs, like their close relatives - halogen lamps (in fact, the same incandescent lamps, but with the addition of halogen-containing compounds inside the bulb to prevent evaporation of the filament material), are the most utilitarian type of bulb because they work with any dimmer. They do not tolerate too high voltage, but they are good enough at its corresponding level. According to reviews of those consumers who wanted to save electricity and increase the service life of light bulbs through the use of dimmers, this works out very well. Many users note that incandescent bulbs can work with inexpensive dimmers as well as with advanced models. They fade almost completely when the dimmer knob is just above the power off position.

Fluorescent lamps

These lamps have mercury vapor inside the bulb.The ultraviolet radiation generated by them, when heated, excites the phosphor, which inside the walls of the flask are coated to emit visible light. Some users in their reviews note that at the bottom of the dimmer control range their lamps simply turn off. The fact of the matter is that they use the so-called compact fluorescent lamps, not intended for use with dimmers: if the homeowner sets a low voltage through this device, the lamp will simply turn off and not dim. To be able to use a dimmer with such a lamp, it must have a dimming ballast, which must be indicated on the packaging. Some standard dimmers will be compatible with this lamp, but not all of them. Consumers should always choose a 220V dimmer indicating the manufacturer of its compatibility with fluorescent lamps.

LED lamp

Их работа основана на способности a light-emitting diode to induce electrons that interact with positively charged "holes" and emit photons that produce luminescence. They are less bright than fluorescent lamps, but the range of brightness adjustment is limited only by the scheme of its inclusion. According to consumer reviews, LEDs are also susceptible to switching off in the lower luminous intensity range, and this can also occur with different types of dimmers. While the incandescent lamp will flicker with voltage fluctuations, the LED may turn off altogether or flicker excessively.

dimmer lamps

Choosing the right lamp

When buying, the consumer must remember that the lampsincandescence can dim from zero to 100 percent, and fluorescent and LED can not be used below 10-20% of their nominal brightness, so that homeowners will not be able to achieve full comfort with them. In addition, fluorescent and LED lamps require a more expensive and sophisticated LED dimmer. In the long term, however, they provide significant energy savings.

Choosing the right dimmer

Современные диммеры, например диммер Legrand (meaning the entire line of the brand), perform various functions, including various types of photocells, motion sensors and timers. When investing in these devices, people should keep in mind that advanced dimmer circuits are designed for high performance light bulbs. While inexpensive devices are adequate for incandescent and halogen lamps.

Summing up expressed by numeroususers dimmer reviews, we can conclude that the greatest mass effect of their use can be obtained in dwellings, illuminated by traditional incandescent lamps. After all, the dimmer allows you to reduce power consumption without replacing cheap incandescent bulbs with expensive fluorescent or LED. If the dwelling is already illuminated by new types of lamps, then the main effect, which is to increase the convenience of lighting control, can be given by “advanced” models of dimmers, for example, a remote dimmer, which allows you to control the illumination of rooms from the remote control without rising from the spot.

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