Quite often it is necessary to replace conventional switches for electrical appliances with new ones due to their rapid wear. They were replaced by more reliable touch switches (TS). The principle of their operation is as simple as possible. The devices can be made by hand. The photo below shows a switch with a sensor located on top and an indicator LED on the bottom.

Appearance of the touch switch

To turn on the light, a light touch on the sensitive element is enough. Touch switches are usually used to control lights, electric curtain rods and other low-power devices.

Advantages of SV

1. Convenient compared to a key switch, which does not always switch immediately. The devices are completely silent and there is no need to make an effort to turn them on.
2. You can choose stylish models that will decorate your premises.
3. Galvanic isolation of the circuit makes the device completely safe. The sensor can be touched with wet hands, the switch is sealed.
4. No mechanisms that can break. The entire circuit consists of electronic elements.
5. Possibility of combining with, as well as creating several switching channels in one device.
6. Possibility of making it yourself.

Operating principle

Any touch switch is functionally divided into three parts:

• a sensitive element (sensor) that responds to the touch or approach of fingers;
• a semiconductor circuit that amplifies a weak electrical signal from the sensor;
• a switch (relay or thyristor) that turns the load on and off.

The figure shows a circuit of a touch switch with a supply voltage of up to 16 V. It is a simple semiconductor cascade amplifier. Used to switch on small loads. There is enough static electricity in the human body to open the first transistor of the cascade if you touch the bare conductor connected to the base with your finger.

Circuit of a simple touch switch from a three-stage amplifier

An LED is connected as a load at the output of the third stage, which serves to demonstrate the operation of the circuit. Instead, a relay is installed in the switch, for which a more powerful transistor can be selected. Copper foil can serve as a sensor.

When you touch the sensor, the first stage opens, then the signal is amplified in the next two and the output becomes 6 V. It is enough to trigger the relay, which turns on the lamp with its contact (not shown in the diagram).

Scheme

The figure shows a diagram of a two-stage touch switch that you can make yourself.

Switch circuit with two transistors

When touching sensor E1, voltage from the human body is supplied to the amplifier through capacitor C1. Relay K1 is connected as a load, which is activated at the next touch, turning on or off its power contacts for powering the lamp. Diode VD1 is designed to protect transistor VT2 from voltage surges, and capacitor C2 smoothes out ripples.

The relay is selected for an operating current of 15-20 mA (type RES55A or RES55B). The value of resistor R1 may need to be changed for the relay to work reliably. First, a 50 Ohm variable resistor is connected instead of it and adjusted until the relay from the sensor works. Then the resistance value is measured and a constant resistor with the appropriate value is found.

The sensor used is foil-coated textolite, copper plate or metal with an anti-corrosion coating. It is easy to make it yourself. If the sensor is installed at a distance from the board, the supply wire should be shielded.

The voltage source is a 9 V battery or a home-made mains power supply. A charger may be fine.

It is better to assemble the switch circuit on a board, but you can also solder it with wires, since there are few parts. To connect them together, wires 2-3 cm long are used. To connect to the contact of the sensor and relay, the length of the wires will be no more than 10 cm.

When soldering, it is important not to overheat the transistors and the 0.22 uF capacitor.

Transformerless power supply from a 220 V AC network does not require a separate source. The triac device is quite sensitive and works reliably. In the diagram below there is no galvanic isolation from the lighting network, but the sensor is protected from high voltage by resistors R1 and R2 with a total resistance of 12 mOhm, as well as field-effect transistor VT1 with a high resistance of the drain-source-gate junction. The sensitivity of the circuit is adjusted by changing resistance R2.

In such circuits, when they are energized, touch is allowed only to the E1 sensor.

Scheme of a touch electronic switch on a triac

The trigger is built on an integrated circuit K561TM2 (DD1). From its output 1, the signal goes to the base of the transistor current amplifier VT2, the emitter of which is connected to the control terminal of the triac VS1. As soon as a voltage of 3 V appears on it, the triac opens and turns on the light source. The next time you touch the sensor, the trigger changes state and an opposite signal appears at output 1, turning off the EL1 lamp.

The load power for this circuit is no more than 60 V. If it needs to be increased, the triac is installed on the radiator.

There are circuits with a dimming function. When you briefly touch the sensor, the lamp will light up and go out. If you hold your hand on the sensing element, the brightness will increase and then decrease. A similar device is convenient to use for a table lamp at your desk. You can set a specific lighting level by removing your hand from the switch. The figure shows a diagram of the touch controller.

Touch dimmer circuit

The signal is supplied from the sensitive element to the K145AP2 microcircuit, and it controls the triac VS1 through the transistor VT1. Power is supplied from a 220 V network. The HL1 LED is a voltage indicator and illuminates the sensor in the dark.

The reliability of any system is higher, the fewer moving elements there are in it. Therefore, when considering a mechanical and touch-type lighting switch, it can be noted that the latter has serious advantages in this sense. But, in addition to reliability, sensor devices amaze, of course, with their futurism. Space design and advanced functionality, what could better meet the trend of modern technology?

Touch switch - what is it?

The sensor device is able to sense any impact on it. Speaking of a switch, such an impact would be a person touching the area of ​​the sensitive zone. But, unlike a mechanical switch, other than a light touch from the operator, no additional effort is required for the device to operate. Moreover, touching the same area again will lead to a change in the state of the device - to the opposite.

A touch light switch, just like a conventional electromechanical one, is designed to turn the lighting on and off. But this does not happen with a direct mechanical break of the contact, but through an electronic circuit, which first analyzes the signal coming from the sensor (sensor) and gives a command to the relay. Therefore, it is incorrect to say that a switch with a sensor device is completely devoid of mechanics. But the reliability of such a relay is much higher than a simple mechanical contact.

The appearance of the device can be completely different. But in all cases, this is a panel on which there is a certain background and the touch zones are clearly marked. For ease of orientation in a dark room, the sensors are illuminated with a special indication. Switches come in one, two or three positions with the ability to switch up to three zones.

What does the device consist of?

Circuit design, all touch switches are similar to each other. Their work is based on the same processes. Therefore, one device node (meaning the switching node) is assembled on the following three main elements:

Connecting the touch switch to the network

Despite the fact that the sensor is a complex electronic device, installing it in a circuit does not require any special knowledge from the installer. All this is explained by the presence in the switch of standard contact connectors, which are also found in mechanical switches.

Also, the size of the sensor seat and its fastening elements are consistent with standard installation boxes.

Let's take a closer look at how to connect a touch switch:

The more switching zones a switch can provide, the more pairs of contacts it will have on the back side.

Connecting the sensor to a table lamp

The general lighting of the room is not always enough for normal work. This happens because the chandelier, as a rule, is located in a certain place on the ceiling and its light may not fall very well on the workplace. The way out of the situation is to purchase a table lamp.

The inconvenience of most table lamps is that the mechanical switch is usually located not on the body of the product itself, but on the power cord. Looking for such a switch, especially near a night light, is, to put it mildly, inconvenient. With the advent of the lamp touch switch, it became possible to correct the situation.

The sensor is better suited for these purposes than a regular switch, because the latter must be embedded into the front panel - this is not always possible to do successfully, from an aesthetic point of view. The touch switch can simply be hidden under the body of the product, bringing it as close as possible to the surface. To install the sensor in a table lamp, you need:

Connecting the sensor to the control panel

The touch switch is easy to use, but sometimes there are times when you need to bind a control panel to it. Most sensors support this feature. This may be necessary if it is impossible for a sick person to approach the switch and in other situations. Using the example of a touch device from Livolo, it is convenient to understand how this connection process occurs:

Device selection criteria

Just like conventional switches, the devices are designed to operate with a certain current and voltage, so when choosing them, you must first pay attention to these parameters. Information can be found on the device body or on its packaging. If the electricity in a real network deviates from the parameters required by the switch, then a stabilizer must be included in the circuit.

Other selection criteria are:

• Number of connection zones to one device.
• The need for a dimmer.
• The need to have a timer, remote control, temperature sensor or other additional function in the device.
• Device type - LED touch switch, for other lamps or electrical appliances.

At the very last stage, you can decide on the design of the product and its compliance with the style of the room where it will be installed.

Advantages

If we compare two types of switches - classic and touch, the latter has a wide range of advantages:

• Ability to work in tandem with most lighting systems and various equipment.
• Longer service life with high operational reliability.
• Safe for human life and health when used even with wet hands.
• Expanded functionality.
• Easy to connect and install.
• Quiet operation.
• Aesthetically attractive appearance.

Using touch switches for lighting fixtures, you can effectively save electrical energy. To do this, buy not ordinary devices, but those that have a dimmer function. This allows you to reduce the voltage supply to the lamp, thereby changing the brightness of its combustion.

Finally

When installing any systems (desktop touch switches or wall-mounted), you should not forget that working with electricity requires extreme care and compliance with safety precautions. Therefore, if you do not have the necessary skills, it is better to invite a qualified electrician for installation.

The idea of ​​controlling lighting fixtures using touch switches is not new; similar switches or light switches were produced back in the last century. But the dimensions of such devices were significantly larger than standard ones, which caused problems during installation. It is also worth noting that the cost of the first touch switches was quite high; naturally, this did not contribute to their popularity. With the development of technology, the situation has changed radically, and today capacitive, infrared and remote switches are in stable demand.

Design and operating principle

Despite the variety of models of touch communicators, most of them have a standard design consisting of the following elements:

1. Housing made of heat-resistant plastic (see A in Fig. 1). The dimensions of the structure allow installation in a typical mounting location of a conventional switch.
2. Electronic unit (B), it includes a power adapter and a semiconductor switch control circuit.
3. Board with capacitive sensors (C).
4. The front panel (D), as a rule, is made of quartz glass; budget models may use other materials.

Figure 1. Legrand six-key wall switch

Now we will tell you how such devices work. The electronic unit monitors the state of the sensor. When you touch a certain place on the front panel of the switch with your hand (it is marked accordingly), the capacitance of the sensor changes. The electronic unit detects this and changes the state of the contactless semiconductor switch, which opens or closes the electrical circuit.

Scope of application

Initially, this type of switch was planned to be used to turn on/off lighting, but the design turned out to be so successful that the scope of its application has expanded significantly. Today, most modern household appliances have touch controls; examples include kitchen stoves, hoods, microwaves, etc.

The only limitation on connecting to touch switches is the power of the equipment; its permissible parameters are indicated in the device passport.

Additional functionality

Modern technical base has made it possible to install microcontrollers in the electronic control unit of a touch switch, which has significantly expanded the functionality of switches and allowed them to fit into the concept of a smart home. Such switches can be controlled by voice, infrared or radio remote control, smartphone via WI-FI or a programmable timer.

The touch switch can be connected to the smart home system and controlled using a mobile phone

Touch switches can be used in conjunction with sensors that respond to motion or light levels. In the first case, such devices turn on a lamp, table lamp or other lighting fixtures when someone enters a room, such as a bathroom. With the second implementation option, the light will turn on at a low light level.

Sesoo Triple Touch Switch and Motion Sensors

Some manufacturers, for example, Livolо, produce touch switches with a dimmer function or that control combined sockets, to which almost any household appliance can be connected.

Livolo touch switch with socket block

Advantages of capacitive switches

Speaking about the advantages of this type of switches, the following qualities should be noted:

Now briefly about the shortcomings. First of all, it is necessary to note the difference in cost with conventional mechanical switches, but it has become significantly less than 10-20 years ago. The price of inexpensive Chinese touchscreen models today is much cheaper than mechanical switches from well-known brands, such as GTS or Electronics.

Sometimes LED lamps connected to touch switches flicker. This may be due to both the low quality of the lighting sources themselves and the low-cost switch models. The problem can be resolved in two ways:

1. Use products from well-known brands (Jazzway, Panasonic, Sapphire, Funry, LightaLight, Tronic, Sesso, etc.).
2. Connect a 0.1 uF 630 V capacitor in parallel with the LED lamp.

Connection

The installation of touch switches is practically no different from the installation of conventional built-in and surface-mounted mechanical switches. You can read more about this process on the pages of our website. Let us remind you how to do this using the example of the kg020gs model from the manufacturer FD Electronics.

Connection algorithm:

Figure 8. Second and third connection stages

Some manufacturers, for example, Livolo, produce pass-through switches for 220 V (their connection diagram is shown in Fig. 9). With their help, you can control lighting from several places.

Figure 9. A clear example of how to connect several pass-through touch contact panels

Each of these switches controls the lighting in the room from different locations. The concept involves using a main switch and one auxiliary (or more). On the main devices there are three terminals, the phase is connected to one, the zero is connected to the other, and the control conductor is connected to the third. Accordingly, such contacts are marked as: L – phase, N – zero and Com – control wire. Assistive devices

Secondary switches are connected through two terminals: N – zero and Com – control contact. Labeling may vary from manufacturer to manufacturer, so it makes sense to study the instructions. An example is the connection diagram for the electronic dimmer et0802193e, or its analogue tt6061a, which can be controlled with a light touch of your hand.

Selecting a touch light switch

Before purchasing a device, you need to determine its functionality. To do this, the following criteria must be taken into account:

1. Power of connected equipment and its connection diagram.
2. Execution corresponding to the type of wiring.
3. Operating conditions (if installation is planned in the bathroom, then a device with moisture protection is selected).
4. Possibility of remote control (remote control or smartphone).
5. Compliance of the design with the interior of the room, etc.

Having decided on the main tasks, you can begin to select a manufacturer. Naturally, you should give preference to well-known brands whose products are reliable. But at the same time, it is necessary to take into account the presence in the model range of switches of devices with the necessary functions. For example, Delumo has devices controlled by a radio remote control, and Sonoff specializes in Wi-Fi devices, Capsens Domuns Line lamps are “tailored” only for their touch switches, etc. There can be many nuances, so we recommend that you study the various options in detail.

Based on practical experience, in addition to well-known brands such as Legrand, we can recommend Vento Electric, Wemmon, Fanri, Merten, CGSS, Steu, Schneider, Ariston, etc.

MakeGood Classic wireless touch switch with remote control and backlight

We recommend monitoring reviews online, where ratings of the best manufacturers are published. Selection criteria are made both by the model range of manufacturers, taking into account functionality and cost, and by other indicators.

Refinement of standard devices

Many people are not happy that the touch zone on the panel is quite small, and to record a signal you need to touch it in the indicated place. Let's give an example of how you can increase the area of ​​indirect surface contact.

You should take the wire and carefully solder it to the place where the signal is supplied from the sensor on the touch board (for this you need to study the circuit diagram of the device). The connected wire is laid around the perimeter of the housing. As a result, such a frame will make it possible to trigger the sensor when touching the front panel without amplifying the signal level.

It should be noted that such an improvement will void the manufacturer's warranty.

DIY touch switch

For those who like to work with a soldering iron, we can recommend several circuits of touch switches that will be easy to assemble with your own hands. Let's start with a simple field-effect transistor circuit, this is exactly the principle that was laid down in the first sensor devices.

Designations:

• Resistances: R1 – 10..15 kOhm (must be selected for sensor response), R2 – 3...5 MOhm.
• Capacitors: C1 – 1000 pF (suppresses false triggering), C2 – 33.0 µF x 50 volts, C3 – 470 µF x 50 V.
• Transistor VT1 – KP 501A.
• Relay K1 can be used of any type whose operating current does not exceed 150.0 mA.

The circuit is powered from a source with a voltage of 12…24 V.

Now let's look at an option based on the NE555 asynchronous RS trigger. The device diagram is shown below.

Designations:

• Resistors: R1 – 1.0 MOhm, R2 – 1.0 MOhm, R3 – 1.0 kOhm.
• Capacitors: C1 and C2 – 15 nF, C3 – 10 nF, C4 – 0.1 µF, C5 – 100.0 µF x 25 V.
• Diodes: D1-D2 – 1N4001, D3 – standard indicator LED.
• Chip – NE555,
• The relay is the same as in the previous electrical circuit.

The above diagram does not need to be configured.

Concluding the topic of homemade sensor devices, we should mention the Ardunio system. On this platform, you can assemble a switching device that can be easily integrated into a Smart Home. In addition, such a device can be easily configured to operate independently, in accordance with a given program.

In addition, the system allows you to create several profiles for specific tasks. However, this will require programming skills. You can get more detailed information about the Ardunio platform on our website.

Note that in the above circuits, a power source with a voltage of 12-24 V is required to power the control circuit. For this purpose, it is best to use switching power supplies. The electronic balance of LED and energy-saving lamps is ideal as such. Detailed information on this topic can also be found on our website.

Briefly about security

When connecting touch control of lighting sources, you should adhere to the same rules and regulations as prescribed for mechanical switches. That is, before starting work, it is necessary to de-energize the line where the installation will be carried out. Further, we adhere to the following standards:

• The switches must be connected to the network in such a way that phase switching is carried out, not zero.
• If the power supply uses a ground wire, it must be connected to the appropriate terminal.
• If stranded wire is used for installation, its ends must be crimped or tinned. Otherwise, contact may be broken, which will lead to heating of the connection.
• Do not use a touch switch with obvious signs of a violation of the integrity of the structure.
• The load must match the parameters of the switch.

Despite the fact that touch switches appeared on our market relatively recently, they have already managed to conquer their niche. And first of all, thanks to its aesthetic design, which looks advantageous against the background of conventional key switches.

Touch switches are a device consisting of a touch panel itself, a switching unit and an electronic control board.

• The touch panel is directly the front part of the switch, with the help of which the connected electrical appliances are controlled. Control is carried out by touching the hand to the highlighted illuminated part of the front panel. When turned off, the indicator lights up blue, when turned on, red. For models with a dimmer, the load is turned on and off with a short touch, and the lighting is adjusted by a long touch on the panel.
• The control board converts the signal from the panel into an electrical impulse, amplifies it and sends a command to the switching unit.
• The switching unit closes or opens the power contacts, thereby turning the load on or off, and also regulates the current, that is, it performs the dimming function.

In addition to capacitive touch switches that are triggered by touch, there are models on sale that you don’t even need to touch, just hold your palm near the switch and it will work. There are also models with a timer, with a built-in dimmer, non-contact, and triggered by sound or movement. The choice in online stores is quite large, everyone can choose what they need.

Installation and connection of the touch switch

Installation is carried out in a standard socket box using the mounting screws included in the kit. To install, you will need to remove the touch panel; to do this, insert a flat-head screwdriver into the special lock at the bottom of the panel and turn it. Then we connect the wires to the switch terminals.

The connection diagram is standard like a key switch or dimmer, that is, into a phase wire break.

There are two terminals on the switch body, labeled L-in and L-load. The supply wire is connected to L-in, and the wire from the L-load terminal goes to the load. If the switch is two-line, then there will be three terminals - L-in, L1-load, L2-load.

After connecting, screw the support into the mounting box and snap the panel into place. That's basically the whole setup. After this, all that remains is to configure the switch and remote control to work together.

The remote control can come as standard, or it can also be purchased separately. To synchronize the switch and remote control, you must press and hold the touch switch button for 5 seconds until you receive a sound signal. Then press one of the three buttons on the remote control (A, B or C) until a beep is heard. After this, the procedure for binding the remote control to the switch is completed and it can be controlled remotely. To reset all switch settings, press and hold the switch sensor for about 10 seconds. During this time, two beeps should sound and all switch settings will be reset to factory settings.

You can bind three switches to one remote control and program the D button so that it turns off three lines at once. The remote control range is about 20m - this is quite enough for an ordinary apartment.

I would also like to note that touch switches are capable of working with any type of lamps - incandescent, halogen, LED, LED strips, etc. True, I read on the Internet that one problem can arise with low-power lamps - they can blink when the switch is off. Perhaps this problem occurs only in some models, since I installed Legrand and Basalte switches and did not experience such a problem.

Technologies do not stand still, and now we already have a touch switch in wide use, which allows us to take the lighting control system in the house to a fundamentally new level.

Our article will tell you why such a device is needed, what it is and how it works. Thanks to this, you can make a touch switch with your own hands for 12 or 220 volts without any problems, and the connection itself, both a home-made device and a purchased one, will not be difficult.

How the device works

The touch switch looks like a standard touch panel and looks like a plate consisting of crystalline glass with markings applied. This dimmer can have a wide variety of appearances. The switch circuit is a semiconductor device. It helps control the energy consumer.
A touch dimmer can be connected to luminaires to control the light level. These can be any lamps. But besides this, you can connect electric curtain rods and other modern electronic devices that are part of the “smart home” system to it.
The device circuit (220 or 12 volts), regardless of the number of lamps connected to it, consists of three main functional parts:

• decorative profile or face plate. A sensitive element is placed on it. The profile has the ability to respond to touch or proximity;
• semiconductor circuit. This circuit is the “soul” of the switch. The circuit is responsible for analyzing, controlling lamps and turning on the lights. It converts the sensitive signal that the decorative profile perceives into an electrical impulse;
• switching part. The dimmer in this part perceives the converted electrical signal. It is responsible for various actions with the electrical circuit: smooth adjustment of the light of lamps, opening, closing.

Dimmer device

The operating principle of the device is based on the following: when you touch the front part, a signal is generated, which is subsequently converted into an electrical impulse and activates the switching part of the device.

What is good about the device?

Touch switch is a modern technological solution for comfortable and efficient control of the operation of lamps in the house. When installing it you get the following benefits:

• the operating life of the light source, regardless of the type of lamp, is significantly increased due to the smooth switching on of the lighting;
• excellent quality;
• high reliability;
• compatibility with any light sources;

Note! The touch dimmer can be connected to any type of light source: diode lamps, induction lamps, incandescent lamps, etc.

Motion sensor switch

• there are models with voltage of 12 and 220 volts;
• the presence of an economical operating mode, as well as the ability to regulate power;
• Possibility of integration into a standard lighting circuit or a smart home system.

In addition, the touch switch today is often equipped with additional functionality. These additional options include:

• the ability to use a dimmer in conjunction with a remote control. With its help, you can remotely control the operation of lamps in the house. You can connect several switches of the same type to the remote control;
• equipping switches with temperature, motion, light sensors, etc.

Note! The most common addition is a motion sensor.

As you can see, using such a switch (for example, 12 volts), you can significantly simplify your life in your own home.

Selection rules

To take full advantage of all the benefits, you need to choose the right touch switch model. When choosing, you must be guided by the following criteria:

• the number of lamps that will be connected;
• dimmer location;
• is it planned to connect additional electrical appliances;
• operating voltage (12 or 220 volts);
• need for additional functions.

Only by taking these parameters into account will you be able to make the right choice.
Now let's look at the most popular models.

Basalte

These are products of the Belgian company Basalte. The company provides a huge selection of a wide variety of touch switch models.

Basalte switch

Such devices are always of high quality, but they are also very expensive.

Livolo

Livolo touch switches are domestic products. Therefore, their price will be several times lower than that of foreign companies.

Livolo switch

At the same time, Livolo touch switches, despite their affordable price, may be slightly inferior in quality. In rare cases, the device may not operate correctly if fluorescent or LED lamps are connected to it.

Legrand

Switches from the French company Legrand are distinguished by excellent quality and functionality.

Legrand switch

But here again you will have to face the high cost of imported products.
In terms of functionality and variety of models presented, all three brands have almost the same distribution on the market in our country. They only differ in price and, slightly, quality.

How to install

Connection diagram

Connection of touch switch models occurs as follows:

Note! Installation of the device is generally similar to that of a standard push-button switch;

• turn off the electricity;
• dismantle the old switch;
• remove the top part of the dimmer;
• we connect the “phase” and “zero” wires according to the diagram to the corresponding terminals;
• We install the dimmer in the mounting box and fix it here with screws and spacers.

As you can see, selecting and installing a touch switch is not difficult. You can do this kind of work without proper experience in about ten minutes. As a result, you will modernize your own home, adding several points to home comfort and coziness.

Details about the motion sensor switch
Selecting a street motion sensor to turn on the lights