What is a dimmer and how does it work?

What is a dimmer, how does it work, and where is this device used? Not every person who does not have knowledge of the basics of electrical engineering is ready to answer this question, despite the fact that in everyday activities this device has to be encountered quite often. A dimmer is a device whose main purpose is to adjust the brightness of the glow of electric lighting devices. Devices are divided into two main groups, depending on the type of lamps served. In practice, dimmers designed for incandescent lamps or for LED lamps find application. One group combines lighting controllers, the principle of which is based on the use of a variable resistor, the other is ensured by a semiconductor device, a triac. Next, we will take a closer look at the device, the principle of operation and the appointment of dimmers.

Resistor dimmer

This device is used, in most cases, as a dimmer control. Let's consider how this dimmer is constructed and what it consists of. In this case, the function of the main working body of the lighting controller is performed by a rheostat or a variable resistor. The principle of operation of such a device is explained by the provisions Ohm's Law. An increase in the resistance of the resistor leads to a decrease in the current value in the circuit of the lighting device, which ultimately reduces the intensity of the filament of the lamp spiral. Despite the simplicity of the design of the dimmer on the resistor, this device has a significant drawback - the power consumption remains unchanged regardless of the light intensity. An increase in the resistance of the resistor will cause a drop in current on the filament of the llama, but at the same time, the total current load of the circuit will not change in a smaller direction, the excess energy spent will be released in the form of heat on the rheostat. Very important in the use of portable lamps equipped with incandescent lamps. Reducing the brightness of the glow absolutely does not contribute to saving battery power.

Dimmers, the principle of which is to use a resistor, are not often, but are used to adjust the glow of semiconductor llamas. In electrical engineering, this control method is called analog. The analog control method has not found wide application for reasons of low efficiency, as well as due to the high sensitivity of semiconductor devices and devices to changes in current loads.

Triac Dimmer

The realities of modern life dictate the need for a thorough transition to the rails of energy-saving technologies, in the light of these trends there is an active introduction of semiconductor lighting devices.To adjust the operating modes of LED lamps, dimmers are especially popular, the principle of operation of which is based on the use of PWM, the generators of which are devices assembled on a triac. In the process of working from the output of the PWM generator, an electric signal with a frequency within 200 Hz is supplied to the LED device. The change in the brightness of the lamp depends on the time period and the length of the positive voltage pulse. Most importantly, the value of current and a given frequency remains unchanged. Graphically, it looks like this:

The device of dimmers on triacs is somewhat more complicated than that of regulators using variable resistors, but the complexity of the design is completely blocked by the indisputable advantages that this device is endowed with:

  1. The process of adjusting the operation of semiconductor lamps occurs at a rational consumption of electricity. An increase in lamp brightness does not require an increase in current load.
  2. The device of the dimmer allows you to provide for the possibility of inclusion and control, both from the installation site of the device, and using remote control.

About, how to make a dimmer do it yourself, we told in a separate article, which we strongly recommend that you read.

Design features of dimmers

Structurally, dimmers are designed as room switches, the park of these regulators is very diverse. They can be designed for both hidden and external wiring, or can be mounted on a din rail in a switchboard. Thanks to modern developments, a wide variety of control methods are available:

  1. Adjustment by button, key, adjusting wheel.
  2. Touch control system.
  3. Remote control.
  4. Management using the wi-fi system, as well as the ability to combine with a smartphone or tablet.
  5. Acoustic control system, response to certain sound signals.

Set dimmer in your home is extremely simple, these devices are widely represented in specialized retail chains. Due to its design features, dimmers are easily installed instead of traditional switches, while they have the same connection scheme. When purchasing semiconductor lamps, you should pay attention to the fact that they are compatible with dimmers, which should be indicated by the marking on the package "dimmable".

Finally, we recommend watching a useful video on the topic:

So we examined the device, purpose and principle of operation of dimmers. We hope that now it has become clear to you how the dimmers are arranged and what they are used for.

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