Dimmer for 220 V incandescent lamps: characteristics, principle of operation and dimmer circuit

Comfort is impossible without the right lighting. This is especially true for the evening time of the day, when the bright light from the lamp can even be annoying. Therefore, a device was specially designed to help you easily change the degree of illumination. This device is a dimmer for 220 V incandescent lamps, which allows you to smoothly control their incandescence. At the same time, such a dimmer helps to save energy.

Device and types

Today on sale you can find a large number of dimmers for various lighting fixtures. One of the most inexpensive and simple in principle of operation is a device that controls the brightness of incandescent lamps. The thing is that the lamp is the simplest lighting device.

An incandescent lamp uses the properties of a certain type of material to emit light when heated. In order for this radiation to be seen, the body temperature must exceed 570 ° C (red spectrum). Heating a substance is achieved by passing a current through it. Therefore, a refractory conductor should be used as a radiation source, the resistance of which to the current will allow converting electrical energy into light. All these qualities are possessed by tungsten, which is used as a filament.

The working temperature of tungsten reaches 2000-2800 ° C, which is why the lamp's emission spectrum is shifted to yellow. At such temperatures, tungsten oxidizes, therefore, to avoid the oxidation process, the filament is placed in an evacuated flask, which is filled with an inert gas. The gas used is nitrogen, argon or krypton.

The principle of operation of the dimmer for incandescent lamps is based on changing the degree of heating of the tungsten filament in the bulb. This is achieved by regulating the strength of the current passing through the light device. These controls are called dimmers. Various types of them can be found in specialized retail outlets selling lighting equipment, but if you wish, you can make a dimmer with your own hands. Its uncomplicated design allows you to assemble and connect the device yourself even to people who do not have special technical knowledge.

Operating principle

The dimmer owes its name to the English word dim, which translates as "dim". In essence, it is an electric power regulator. Its simplest type is a rheostat, but it is not used to change the luminous power of devices due to its low efficiency. Another type is the autotransformer. However, its large size and impressive weight make the use of an autotransformer inconvenient.

The development of semiconductor devices made it possible to use new technologies for dimming, operating on the principle of frequency conversion. Thus, dimmers for incandescent lamps are divided into two types:

• analog;
• digital.

The principle of an analog device is based on the extraction of energy from a lighting device by changing the line resistance. For example, in the case of using a rheostat, which is a variable resistor, there is a change in resistance in the circuit with a connected light bulb. To do this, a variable resistor is connected in series to the filament circuit. An increase in its resistance leads to a decrease in the current flowing to the lamp, which means that the filament heats up less and the glow becomes dimmer. But with this approach, power consumption does not decrease, part of it is released on the rheostat, leading to its heating.

The disadvantages of using analog regulators are almost completely solved in digital devices. They are based on the principle of pulse width modulation (PWM), which allows you to control the supply of power to the load. This is achieved by changing the duration of the pulses at a certain frequency of the signal. For this, switching elements are used, which are assembled on transistors operating in a key mode, and a generator - a PWM controller. The latter's task is to manage electronic keys.

In the closed state, the current through the switch is very small, which means that the dissipation power is negligible. In the open state, despite the high current, the resistance is also small, and the heat losses are negligible. The greatest amount of heat is generated at the moment of switching the key. The change in the luminosity of the illuminator depends on the time period and the duty cycle of the signal pulse, while the current value remains constant.

Features and capabilities

The use of dimmers has several advantages over simply turning the lights on and off. First of all, this is additional comfort, and secondly, energy savings. Modern devices allow you to change the lighting without even touching the light switches due to the possibility of using the remote control. The following main advantages can be highlighted:

• improving the energy efficiency of lighting;
• smooth switching on and off of light;
• extending the life of lighting fixtures;
• work of lamps according to the programmed algorithm.

Today manufacturers offer devices that differ in type, cost and set of additional functions. But at the same time, disadvantages are also noted. First of all, it is sensitivity to overheating, therefore, it is not recommended to install them in rooms with high temperatures. In addition, due to the peculiarities of the device operation, radio pulses appear, which can become a source of interference.

You should be aware that incandescent lamps have no inductance and capacity. They are inertial devices. This means that with a decrease in power consumption, the color temperature of the light changes. From the yellow spectrum, it shifts towards the red radiation. Low power lighting can be frustrating, as some manufacturers have built in a cut-off threshold in their devices. When a certain value is reached, the lamp turns off immediately. The main characteristics of the device include:

1. Power. This parameter shows how much power the illuminator can be connected to the dimmer. When buying, you need to choose a device with an indicator of 15-20% more than the planned load power for connection. This will prevent the device from overheating and malfunctioning.
2. Degree of protection. The electrical device must have a protection class. The minimum class must be IP20.
3. Contact group material. Copper contacts are best, but alloy is often used.
4. Control type. It can be rotary, push-button, touch or remote.
5. Installation type. Such devices can be built-in or remote. The first type of device is designed to be located instead of a light switch. Devices of the second type are connected to an outlet with a voltage of 220 volts and have their own outlet, into which the lamp is already connected directly.

Instrument manufacturers

When buying a device, last but not least, you need to pay attention to its manufacturer. The purchase of a low-quality product can lead to a fire, so it is better to give preference to well-known manufacturers. Usually they have an extensive network of service centers, due to which warranty repairs are carried out in the shortest possible time, but most often the product is simply changed to a new one. The leading companies producing dimmers for incandescent lamps include:

1. Legrand. French company specializing in electrical products. It occupies one of the leading positions in the market and is considered reliable and safe. Her series Valena and Celiane are in great demand.
2. Schneider Electric. Their products are easy to install and safe in operation. Popular series: Merten, Prima, Sedna.
3. Nootechnika Agate. Russian manufacturer of electrical accessories. The products meet the high standards of European quality. Most often, when buying, they pay attention to the Agat-D-1000 remote dimmer.
4. ABB. The dimmers from the Swedish-Swiss manufacturer are made in an original design and are presented on the market in a wide range. Their Busch Duro products are considered classics of light control devices.
5. Makel. The manufacturer from Turkey has established itself as a high-quality and reliable manufacturer, producing mainly budget-class products. Defne and Lilium Natural Kare series will satisfy any customer.
6. LN-MINI. The Hong Kong-based firm is known for its miniature dimmers designed to fit into table lamps.
7. Lezard. Subsidiary of the Turkish company DERNEK GRUP. Every year its products become more and more popular. The most famous series is Mira.

Circuitry of devices

There are quite a few technical solutions for the manufacture of dimming devices. But their key blocks are of the same type - these are controls and a control module. The simplest version of the dimmer circuit for an incandescent lamp contains no more than five radio elements and is easy to repeat even for a novice radio amateur, while complex multifunctional devices contain microcircuits and software code.

Simple circuits can be carried out by surface mounting, but for complex devices you will need to make a printed circuit board. When assembling a device of any complexity on your own, you should be careful and observe accuracy, since the work is associated with a life-threatening voltage of 220 volts.

Rotary dimmer

Such a circuit does not contain scarce radio components, and its key element is a triac. The essence of the circuit boils down to the fact that the current will appear on the lamp only if an unlocking signal appears on the control electrode of the triac. When it opens, the load will connect.

The generator in the circuit is implemented on two triacs VS1 and VS2. When connected to a 220 volt network, the capacitors C1 and C2 begin to charge through the resistors R1 and R2. As soon as the voltage level reaches a value that allows VS1 to open, a current appears, and the capacitor C1 is discharged. The greater the resistance of the R1-R2 chain, the slower the charge occurs, which means that the duty cycle of the pulses increases. When the resistance R2 changes, the pulse duration is adjusted.

Radioelements table:

Designation	Name
VS1	BT137 600E
VS2	DB3
R1	1 MOhm
R2	27 kΩ
C1	22-100 nF, 300 V
C2	22-100 nF, 300 V

Dimmer on a microcontroller

This type of circuit is used in dimmers with remote control. The main element of the device is the DD1 microcontroller. The mains voltage is fed to the controller input through the voltage divider R8-R10. The transition of a sinusoidal signal through zero is characterized by a falling voltage front, which causes an interruption of the microcircuit program.

VD3-VD4 elements form a stabilized half-wave rectifier. Capacitor C6 and resistor R6 are needed to protect the parametric stabilizer. To assemble such a device with your own hands, you will need to make a printed circuit board, and the level of knowledge in electronics should be average.

Capacitors C1 and C2 act as a filter and are designed to smooth out the rectified voltage. In the event of a voltage failure in the 220 V network, the C5 discharge occurs through the VD1 diode. A key is assembled on the VT1 transistor, which discharges C4 when the user interacts with the sensor plate. You can even use a homemade metal plate glued to the back of the key of any switch as it.

The triac must be designed for a maximum operating voltage of at least 600 volts, and its current must be twice that required by the load. If a unit is present on the fourth pin of the microcontroller, then the triac is closed. To open it, a signal pulse with a duration of at least 15 μs is generated.

The radio element is installed on the radiator. Any photocell with a carrier frequency of an infrared signal of 36 kHz is used as a photodetector.