What is dimmer and how it works?

  • Dec 26, 2019

Electricity in the modern home fulfills many functions, one of the main among them - the lighting. In some cases, the brightness is excessive and to create the necessary level of comfort, it is necessary to subtract. Special control is used to solve this problem: Dimmer.

The name of the device is derived from the English verb "to dim", which means to dim, mute, fade and points directly to its destination.

Actually implements the functions of the dimmer controller electric power supplied to a load and as such is suitable for operation with any suitable devices.

In the lighting system, it can be used:

  • dim the lights in the bedroom before going to bed;
  • install emergency lighting mode to save power;
  • to solve some of the design challenges that require specific lighting solutions based on Time regulated light flux for the purpose of optical isolation of any areas space.

electronic dimmers

The bulk of contemporary dimmers are controlled by an electronic device which includes inlet lighting unit according to the scheme shown in Figure 1, and allows a wide range to change the power flowing through current. controller function performs a thyristor circuit which operates in the switching mode, and the control signal is taken from a circular potentiometer or created electronic control circuits.

Picture 1. The circuit switching power supply circuit in the dimmer lighting unit
Picture 1. The circuit switching power supply circuit in the dimmer lighting unit

The input is the sinusoidal mains voltage, output current regulation carried cutoff portion sine half-wave. cutoff angle is determined by the control voltage, which is applied to the control electrode. One embodiment of the concept shown in Figure 2.

Figure 2. Schematic diagram of the dimmer
Figure 2. Schematic diagram of the dimmer

Thyristor dimmers structurally executed as a unit, is fitted as standard mounting socket on the switch position. An example of execution is shown in Figure 3.

Figure 3. Typical performance of household dimmer
Figure 3. Typical performance of household dimmer

Selection principle output current cut-off part of the half-wave inevitably leads to an increase in electromagnetic interference. To eliminate them in high-quality devices installed LC-filter in cheap controller limits the throttle.

There is also protection circuit against short circuits.

Additional service features

Changing the current due to variations of the control voltage makes it possible to easily incorporate electronic dimmer in the complex control systems. Thus, it can be used to remotely switch like conventional clap their hands, and on a radio or infrared channel. With appropriate programming of the controller is implemented optional presence of home owners by automatically switching on and off lights in different rooms.

Other varieties of fixtures regulators

In addition to the electronic dimming controller functions may perform other device.

The most simple embodiment - a variable resistor which is connected in series with the lighting device. To reduce the brightness resistor increases, and vice versa. potentiometer possible application, which force current through the lamp is set by varying the voltage at the tap. The disadvantages of such regulators are obvious: too much loss of power due to the low efficiency and the related strong heating.

Dimmer based autotransformer has a sufficiently high efficiency and furthermore does not distort the alternating current waveform. However, it is not very suitable for mass use in household electrical networks due to such fundamental flaws like unsatisfactory weight and size parameters, as well as the great efforts that have to be put on the handle management.