Table lamp voltage regulator circuit. Thyristor brightness control for a table lamp. Dimmer device for incandescent lamps

Dimming with in English translated only as “darkening”. What a dimmer is, what they are and where else they can be used we will tell you in this article. From origins to final implementation. Most main question Can LED bulbs be used with a dimmer?

What is a dimmer and why is it needed?

Dimmer - electronic device capable of regulating power by regulating the voltage supplied to the load. The definition is very dry and boring, let's get more in simple language Let's explain the principle of operation.

Power depends on the voltage and current in the load. This means that if you reduce one of the components, the power will also decrease. Voltage and current are related by Ohm's law, which means you can reduce the power of your device (brightness of the lamp) by increasing the total load resistance. That is, use ballast resistors, chokes or capacitors.

Ballast power absorbers - convert excess energy into heat and have low efficiency. To regulate the power of the device, in our case the brightness of the light bulb, you need another device - a dimmer.

Is it possible to connect LED lamps via a dimmer? Can. But not everything will be consistently regulated. Here you need special LED lamps for dimmer.

LED lamps, dimmable , Suitable for use with any regulator. But there are some nuances in the difference between the type of voltage regulation. This is determined by the dimmer's circuitry; the differences will be described in detail in the following sections of the article. The type of dimmer determines how well the LEDs will be regulated.

Which LED lamps can be used with a dimmer? In this matter, everything is extremely individual. It all depends both on the circuit of the light bulb itself and on the circuitry of the regulator. In general, the so-called dimmable LED lamps.

What types of dimmers are there?

Power regulators can be divided into two large groups:

• For use in circuits AC voltage(220V);
• for operation in constant voltage circuits (for 12V LED strip).

Drills also need a regulator to adjust the speed; it is located in the button.

It can be used for a variety of purposes, listed in order of popularity:

1. Light brightness adjustment, dimming of LED and incandescent lamps;
2. adjusting the heating element temperature in various heaters;
3. adjusting the speed of the commutator motor.

What are the differences between dimmers?

If you are going to use a switch with brightness control, you first need to find out what they are. And in general, can all LED lamps be dimmed?

Dimmers differ according to the following criteria:

• By type of installation;
• on execution and method of management;
• according to the method of regulation.

Let's take a closer look at each of them.

By installation type

For outdoor installation– surface-mounted switch with dimmer for LED lamps. To install such a device, you do not need to drill a niche in the wall; it is simply mounted on top of the wall. It is very convenient to use in cases where the interior is not a priority or external wiring is installed.

For indoor installation– will fit perfectly into any interior, such as this one.

For DIN rail mounting are very specific and at first may seem that they are not practical. However, this dimmer for LED lamps works with a remote control remote control, while hidden from prying eyes in the electrical panel.

By execution

According to the design, the light controller for LED and incandescent lamps can be:

• Rotary;
• rotary-push type;
• push-button;
• sensory;

Turning- one of the most simple options LED lamp brightness control, looks unpretentious and has simple functionality.

Turn-push looks almost the same as the rotary one. Thanks to its design, when you press it, the light turns on with the same brightness as it was set the last time you turned it on.

Push-button regulator for LED lighting it looks more technologically advanced and will fit organically into a modern apartment. Like this switch with a dimmer for LED lamps.

Touch models and can be completely different - from luminous circles to smooth one-color panels for adjusting the voltage of LED lamps.

According to the adjustment method

Dimmers vary not only in their design, but also in their operating principle. E This applies specifically to AC dimmers.

The first type of dimmers is more common and cheaper, due to the simplicity of its circuit - this is leading edge cutoff dimmer(English) leading edge). A little further on, its operating principle and circuit will be discussed in detail; for comparison, take a look at the type of voltage at the output of such a regulator.

The graph shows that the remainder of the half-wave is supplied to the load, and its beginning is cut off. Due to the nature of the load switching on, interference is generated in the electrical networks, which interferes with the operation of televisions and other devices. A voltage of the set amplitude is applied to the lamp, and then it fades out when the sine wave passes through zero.

Can a leading edge dimmer be used for LED lamps? Can. LED lamps with a dimmer of this type will only be well adjustable if they were originally designed for this. This is evidenced by the symbols on its packaging. They are also called “dimmable”.

The second type works differently, creates less interference and works better with different light bulbs - this trailing edge cutoff dimmer(English) falling edge).

LED lamps with this type of dimmer adjust better, and its design better supports non-dimmable light sources. The only drawback is that these lamps can adjust their brightness not from “zero”, but in certain range. At the same time, dimmable LED lamps are simply superbly adjustable.

The best solution is to use a Falling Edge dimmer for LED lamps.

A special word can be said about ready-made LED lamps with adjustable brightness. This is a separate class of lighting devices that do not require the installation of additional regulators, but have them in their design. Their adjustments are made using buttons on the case or from the remote control.

Dimmer circuits

Dimmer for 220V voltage, with leading edge cut-off, works on the principle of phase-pulse voltage control. During operation, the elements of such a dimmer supply voltage to the load at certain moments, cutting off part of the sinusoid. This is depicted in detail and more clearly in the graphs.

The area of ​​the sinusoid shaded in gray is the area of ​​the voltage or its effective value that is supplied to the load (a lamp or any other device described above).

The red dotted line shows the voltage waveform at the dimmer input for led lamps. In this form it is served through regular switch no adjustments .

How to connect LEDs via a dimmer?

Component ratings and all information are indicated on the dimmer diagram.

The device is installed in a break in the wire going to the light source, motor, heating element or any other device.

The logic of the circuit is as follows: capacitor C1 is charged through the chain R1 and potentiometer R2. Depending on the position of the potentiometer, the capacitor is charged to the opening voltage of the dinistor VD1.

The circuit used a DB3 dinistor, which is approximately 30V. Through an open dinistor, a control pulse for opening a triac (bidirectional thyristor) is supplied to its control electrode.

The greater the resistance set by the potentiometer knob, the longer it takes for the capacitor to charge, respectively, the later the dinistor-triac circuit will open, and the voltage will be lower, since most of the sine wave will be cut off. And vice versa - less resistance means more voltage at the output of the regulator.

There are many options for circuits on the Internet with all sorts of modifications, all of them are good. Here is the simplest circuit; the figure shows the installation of this version of the circuit.

How to adjust LED lighting

What light bulbs can be used with a dimmer? When mainly incandescent lamps were used for lighting, everything was simple - a regular dimmer could easily cope with adjusting the brightness.

Incandescent light bulbs were replaced by energy-saving fluorescent light bulbs and could not be dimmed at all. Of course, there were electronic ballasts for tubular fluorescent light bulbs with dimmable capabilities, but they were extremely rare and they were expensive.

Now energy-saving lamps are being replaced by LEDs. The process of emitting light quanta, although complex, is, from a regulatory point of view, perhaps simpler than regulating gas-discharge light sources.

Dimmable LED lamps - what are they?

What does dimmable LED lamp mean? This is a light bulb that can be dimmed using ANYONE dimmer, which is designed for alternating or direct current (depending on the type).

Its power circuit includes functions for changing brightness, depending on the supply voltage. Dimmable LED lamps work with dimmer circuits like the one shown above.

The network dimmer regulates the supplied voltage. This means that at any voltage values, within the range specified by the manufacturer (it is indicated on the light bulb box), the lamp circuit will strive to maintain the specified current. Brightness in turn depends on current.

Regular LED lamps cannot be adjusted; at best, they will simply turn on and off; at worst, they will burn out at low values ​​set on the dimmer.

The cheapest LED lamps have a quenching capacitor. Even if they are regulated, it will be only within very narrow limits, which means they are also not suitable. Example of dimming conventional LED light bulbs look at the video.

Dimmable LED lamps 220 Volt

Adjusting the brightness of 220V LED lamps is difficult because there is a current stabilization circuit installed on a specialized driver. Its task is to stabilize the output current to ensure a uniform and long-lasting glow of the LEDs, regardless of the supply voltage.

Conventional LED lamps are not very dimmable. To choose the right LED lamp for a dimmer, you need to carefully study the description and symbols indicated on the box and body of the light bulb.

LED lamps with dimming can be recognized by the inscription: “for dimmer”, “adjustable” or something similar; perhaps a conventional image of a dimmer will simply be drawn, as in the examples below.

Is it possible to adjust the brightness of LED lamps running on DC?

The photo shows a led dimmer for a 12V LED strip. Let's figure out how such a dimmer works with LED lamps.

For chains direct current The operating principle of the regulator is different. Here, a bipolar or field-effect transistor is used as a metering element, and a pulse generator with a variable duty cycle is used as a metering element.

The method of this control is called pulse width modulation (PWM). To understand how this works you need to look at the graphs.

Vcc is the voltage at the DC dimmer input, Vaverage is the output voltage. You can see how the average voltage changes. As the pulse duration increases and the pause length decreases (we increase the duty cycle), the output voltage increases.

Above is the principle electrical diagram“PWM brightness controller for LED lamps on NE555.” It can act as a device for dimming LEDs. It works like this:

NE555 is a timer, connected here in the pulse generator mode, the frequency and duration of which is set by an RC circuit consisting of R2, potentiometer R1 and capacitor C5, as in the previous circuit, the potentiometer regulates the charging rate of the capacitor, and the pulse width is formed in accordance with the charging speed.

Initially, the circuit produces symmetrical pulses, that is, the pause length is equal to the pulse length. But thanks to the presence of a potentiometer and a chain of two diodes VD1 and VD2, the capacitance is charged and recharged through different resistances of the potentiometer, or rather through different pairs of its contacts.

Therefore, PWM adjustable pulses are generated with a constant frequency, but a variable duty cycle.

If you use it in a car or for dimming an LED strip, you can eliminate the additional 9 volt power supply based on the 7809 linear regulator and supply power to the first point after it in the circuit.

But here are photos of a homemade dimmer for LEDs, if necessary, you can copy the location of the tracks and repeat it. Or assemble it on a breadboard.

A video of how dimming LED lamps works using this circuit, using a side-glow strip as an example, is located below.

Using this circuit, it is possible to dim 12V LED circuits and any other DC load. For example, adjust the speed of revolutions of a PC cooler, brushed motors, heaters, in general, anything you can think of. In one of the articles we already talked about.

What dimmer is needed for LED light bulbs?

To select a dimmer for LED lamps and ensure their compatibility, you must first decide which lamps you will use. If you are planning to buy 220V LED light bulbs, phase-pulse devices, which were discussed at the beginning of the article, are suitable for this. Take models with trailing edge cut-off.

For low-voltage DC lamps (for example, 12V, which are used in spotlights, table lighting or car lamps) - any PWM controller or dimmer will do LED strips. They all work on the principle of pulse-width modulation; linear regulation is already a thing of the past.

It is also better to buy special LED lamps for dimmer. Although they are more expensive, there will be no problems with their adjustment. You will create the desired lighting solution only if you choose the right dimmer and LED lamps for it.

Share your experience in adjusting the brightness of LEDs and LED lamps in the comments!

Previously, room lighting was controlled by a rheostat. A significant drawback of these devices was their high power consumption, regardless of brightness. At minimum lamp power, electricity was consumed in the same amount as at maximum, since most of it heated the rheostat.

Adjusting the lighting in the room

Advantages and disadvantages

Nowadays, an electrical load regulator (dimmer) can be bought at an electrical goods store. It is mainly used to change the brightness of lamps different types and has the following advantages:

• change in lamp intensity;
• setting automatic brightness change Automatic light dimmer using a timer;
• remote control;
• used as a switch and to set lamp glow modes: smooth change, creation of light patterns, blinking;
• increasing the durability of lamps due to soft starting;
• saving energy consumption.

Regulators have disadvantages:

• extraneous interference interferes with the operation of devices that do not have filters;
• generation of interference for other devices receiving radio signals;
• not all devices save energy;

Dimmer Types

The simplest device with adjustment has a switch and a rotatable knob. The brightness of the regulator depends on the position of the potentiometer. The dimmer is suitable for controlling incandescent and halogen lamps. In terms of power, it is selected at least 15% higher than the connected one maximum load. It should have built-in protection against short circuit. The simplest option is a fuse.

Dimmer comes in the following types:

1. Overhead. Most often it contains an auxiliary rheostat and is used for LED strips.
2. Passage - for large areas of premises.
3. Two- and multi-channel – selected by the number of lamps and control modes.

Where should you not install dimmers?

1. In public areas where frequent use will not allow them to perform their basic functions. Everywhere you can install devices for smooth switching of lamps built into switches, which can increase their service life.
2. In places where there is no certainty regarding the installation of lamps.

Methods of regulation

1. Mechanical - turn the handle. First, the dimmer is turned on until it clicks, and then the brightness is set. The turn-and-press device is more convenient, since you can use a switch with constant adjustment of the regulator.
2. Electronic: push-button, keyboard. Can be used as a switch and regulator.
3. Touch - the control panel implements many different functions.
4. Remote – control via radio signal or using an IR remote control.

Types of lamps for dimmers

• Incandescent and halogen lamps 220V. To change the light intensity, any dimmers can be used, since the load is only active (does not have inductance or capacitance). The disadvantage is that the spectrum shifts towards red as the voltage decreases. The power limit for dimmers is within the range of 60-600 W.
• Low voltage halogen lamps. For them, we can use a step-down winding transformer, which requires a regulator capable of working with inductive load. It is marked RL. When using an electronic transformer, capacitive loads are installed.

Halogen lamps require a smooth change in voltage, which increases their service life. Latest models determine the type of load and adapt to it, changing the control algorithm. You can simultaneously regulate different groups of lamps: incandescent and halogen.

• Fluorescent lamps. If they are started via a switch, glow starter and electromagnetic choke, a regular dimmer and rheostat are not suitable for them. Here you need electronic ballasts (EPG).
• LED bulbs. For them, voltage regulation leads to a change in the spectrum. Therefore, the LEDs are regulated by changing the duration of the supplied pulses. In this case, flickering is not noticeable, since their repetition frequency reaches 300 kHz.

Connecting regulators to the load

The connection to the load is made in series (Fig. a). The regulator works the same way as a switch, but it is advisable to install the latter separately, since if it fails due to frequent switching, you will have to replace the expensive dimmer with a new one.

Dimmer connection diagrams

The main requirement is to maintain polarity. The phase is always connected to the dimmer input terminal, marked with the letter L, and from the output terminal the wire goes to the lamp. The phase can be detected using a voltage indicator.

A switch is often installed in the phase wire gap (Fig. b). It is located closer to the door, and the dimmer is located near the bed for easy control.

You can install another regulator and connect them together in parallel (Fig. c). To do this, 3 wires from each device should be routed into the junction box. Similar switching, similar to pass-through switches, is done in long corridors.

The use of dimmers differs in the number of loads. The single method consists of connecting one device or combined into a common group. The next control method is based on accent lighting to highlight individual zones.

Adjustable room lighting

Dimmer connection

The regulator is mounted in the installation box like a regular switch. First, it is connected when there is no voltage in the supply wires, and then installed in the box. Then the frame and brightness control knob are put on.

The basic scheme for regulating the light intensity of lamps for most conventional devices is the same. The difference is only in the additional parts to provide smoother handling and create stability at the lower limits.

To supply voltage to the lamp, the triac should be opened (Fig. a). To do this, a voltage must be created between the electrodes.

Circuits with triac regulation for incandescent lamps: a – the simplest; b – improved

At the beginning of the positive half-wave, capacitor C is charged through a variable resistor R. When a certain value is reached, the triac opens. At the same time, the lamp lights up. Then the triac closes and a similar situation occurs on the negative half-wave, since semiconductors pass current in both directions.

Thus, the light bulb receives “stubs” of half-waves with a frequency of 100 Hz, which was not the case when a rheostat was used. As brightness decreases, light flickering becomes more and more apparent. To avoid this, parts are added to the diagram, as shown in Fig. b. Triacs are installed according to the current load, and the permissible voltage is 400V.

By selecting the values ​​of resistors and capacitors, you can change the initial and final ignition moments and the stability of the lamp glow.

For LED lamps

Despite the efficiency of LED lamps, garlands and strips, energy saving issues also apply to them. Often there is a need to reduce the brightness of the glow. LED lamps with conventional dimmers do not work and quickly break down during the regulation process. For this purpose, special regulators of two types are used: changing the supply voltage, controlling the pulse-width modulation method - PWM (load switching intervals).

Devices that control illumination by changing voltage are expensive and bulky (rheostat or potentiometer).

A modern regulator is a complex device that provides smooth starting of lamps, brightness control and setting light switching modes using a timer.

An LED lamp differs from conventional strips and assemblies, which can only be connected using additional devices. Its main features are as follows:

1. Availability of standard sockets of types E, G, MR for connection.
2. Ability to work with the network without additional devices. If the lamp is powered by a voltage of 12V, the auxiliary devices are specified in its characteristics.
3. The generated luminous flux should not differ significantly from standard values.

To ensure the required operating mode, a driver is built inside the lamp that performs useful features. If it provides for dimming, this is stated in the passport and on the packaging. The brightness of such lamps can be adjusted using conventional regulators.

If dimming is not provided, you should purchase special control devices with PWM regulation. They differ in installation types:

• modular (in distribution panels) with control from remote controllers, remote controls or via special buses;
• located in an installation box, like a switch, with rotary or push-button control;
• remote units mounted in ceiling structures (for spotlights and LED strips).

PWM-based regulators operate on expensive microcontrollers that cannot be repaired. Easier to make homemade device based on a simple microcircuit. The dimmer, based on the NE555 timer, operates stably at a voltage of 3-18 V with an output current of up to 0.2 A.

Dimmer circuit for LED lamps

The frequency of oscillations is ensured by a generator consisting of a resistor and a capacitor. The value of the variable resistor can be used to set the interval between turning on and off the load at output 3 of the microcircuit. Field-effect transistor here it serves as a power amplifier, since the microcircuit cannot cope with the load from LED lamps. If the current through them exceeds 1A, the transistor requires a cooling radiator.

For fluorescent lamps

The brightness of the lamps can be adjusted using electronic ballasts, which perform the main function of starting them. Simple scheme shown in Fig. below.

Control fluorescent lamp using electronic ballasts

The voltage to the lamp is supplied from a frequency generator of 20-50 kHz. The circuit formed by the capacitance and the inductor resonates and lights the lamp. To change the current and thus the intensity of light, you need to change the frequency. Dimming is carried out only after the lamp reaches full power.

The adjustable electronic ballast is created on the basis of the IRS2530D controller with 8 pins. The device is a 600V half-bridge driver with triggering, dimming and failure protection functions. The integrated circuit allows you to implement all the necessary control methods through 8 pins and is used in many ways to change the brightness of lamps.

Block diagram of electronic control of fluorescent lamps

Choice. Video

It is better to learn about the correct choice of dimmers in advance from the video.

When purchasing a dimmer, you should carefully study it specifications and determine what types of lamps it is intended for. Choosing the right device makes it easy to connect it yourself without the help of specialists.

Or a power regulator - a device that regulates power (usually lighting lamps or heating devices). In our case, power reduction is achieved by lowering the voltage.

This dimmer is interesting because it does not have a single moving part (there is nothing to poke or twist), and control is carried out by touching the lamp body.

Description of the process of installing this power regulator in a table lamp and minor difficulties when working with it under the cut.

This power regulator looks like a matchbox with four wires. Exact dimensions: 4.5cm x 3.5cm x 1.4cm. The length of the wires is about 10 cm. By the way, they were immediately stripped.

The connection diagram is embossed on one side of the case (I don’t like it because it has three wires going to the light bulb).

And on the other hand, the operating parameters of the device.

On one side it is written about the network frequency of 50Hz, on the other it is allowed to be used with a frequency of 60Hz. In any case, I don’t have friends in Japan, so I won’t be able to test the performance at 60Hz. The situation is similar with the input voltage (most likely, it will start from 110V).

The case is secured with a couple of latches and is very easy to disassemble.

The dimmer is controlled by a packageless microprocessor, which for some reason sticks out from the main board (saving space?).

The power regulator is designed so that all the load current flows through the output transistor. It is this detail that limits the maximum permissible power of the light bulb.

On one of the sites I found a picture that assures that if the transistor is rectangular, then the dimmer will withstand currents of up to 3A.

We take 3A at a voltage of 220V and get a maximum power of 660W. Now we think why it is needed. The dimmer has no indication of operation. This means that it makes sense to connect only lighting devices to it, which themselves will be indicators. Incandescent lamps with a total power of more than half a kilowatt will ruin the owner at the first attempt to pay the electricity bill, and LED floodlights of such power can easily illuminate an entire hangar (and there is no need for touch control of power). So I didn’t even try to connect more than 100W (namely, this figure is indicated in the product description) and didn’t look for the characteristics of the transistor according to the markings.
But let's get back to the insides.

On back side normal soldering but with a small amount of flux that has not been washed off.

The wires are kind of strange. They indicate a cross-section of 0.5 mm^2, but wires of the same cross-section produced by Podolskkabel are clearly thicker. I soldered these wires, and when I installed them in the lamp, I soldered them on.

Later it took a quick fix connect the speakers to the amplifier in the "robot" on. There was nothing except these unfortunate four wires. At the fair, one of the wires managed to break (I still don’t understand how) and the robot spoke at half capacity.

First start

I really don’t like the diagram of the body, so I drew my own:

I didn’t immediately realize that the ring on the yellow wire could be put on the cartridge securing screw.

Installation

We can only hope that the black electrical tape is as strong as the blue one, and that the ties do not burst (although it would be better to redo it).

Lamp selection

This is where an unpleasant surprise awaited me. Instead of three operating modes, this light bulb works in only two (the driver counts the middle and maximum modes as one). Those. doesn't work --> low light --> bright light --> bright light --> doesn't work. Most likely, the lamp is made for a dimmer with smooth adjustment, hence the jamb.

Underwater rocks

• This dimmer only works with incandescent or dimmable LED lamps;
• the lamp body must be a conductor (even paint can interfere with the operation of the touch sensor);
• Now your animal can also control your lamp (if it touches it with hairless skin, such as its nose).

Conclusion

Go for it!