Description of the circuit diagram of an acoustic switch. Cotton switches - application and DIY production

You can control lighting not only using classic switches, but also using special modules that allow you to turn the light on or off remotely. A cotton light switch is one of these devices; you can buy it at any electrical store and install it yourself.

Principle of operation

This acoustic switch operates on a special microcontroller that allows you to turn off the light by clapping your hands. Of course, such a control device can be used not only to control a lamp, but also many other electrical devices: fans, air conditioners, transformers.

The simplest sound switch consists of an electronic microphone in which a preamplifier is installed. Thanks to this part, any sound that enters the device is amplified several times, due to which even the smallest pops are perceived by the sensitive element. The operation of the amplifier itself is additionally controlled using transistors VT1 and VT2. The circuit is regulated by two resistors R2; rectifying diodes VD1 and VD2 are installed to level the signal.

When a clap sounds, the signal passes through the microphone and is amplified, after which it is converted into an electrical impulse. This pulse is equalized by rectifying diodes. The sound at which the light turns on is controlled by a resistor, i.e., if the sound of the clap does not exceed a preset value, the light bulb or other device connected to the switch will not turn on. After leveling the signal on the capacitor (indicated C8 in the diagram), the voltage increases, then opens transistor switch VT3.

Turning the light off and on is done by alternately discharging and charging the capacitors. After a full cycle of repeated clapping, the resistor and capacitor C10 will discharge within 4 seconds, and the device will go into the off state.

Device installation

You can assemble a simple cotton acoustic switch with your own hands; it consists of the following parts:

1. Resistors;
2. Capacitor C12;
3. Diode bridge (say, VD7-VD10);
4. Transistors.

Please note that the capacitors must be at least 40 Volts. But not everyone likes to fold it themselves. electronic devices, so it will be easier to buy a cotton sound switch from the store. There you can choose a model to suit any needs and capabilities.

The installation of the cotton regulator is carried out according to the classical scheme, in which it is used together with a conventional one-key or two-key regulator. Each individual device has an individual connection diagram, but in principle they are all very similar. In short, you need to connect a single-key model to the network so that it powers the cotton one. How to do it:

1. The standard operating diagram of the switch and lamp is as follows: power is supplied from the panel through the distribution box to the standard switch. The neutral from the shield is led to a lamp (or several lamps). The lamps are connected in parallel to the disconnecting device;
2. You need to break the power circuit that goes to the key switch and install it on the acoustic one. It's very easy to do. The main advantage of such a device is its small size. There is no need to trench the wall, since such a controller is mainly installed on the lamp body;
3. As a standard, the switch has two pairs of wires: white and black. White ones are allocated for power, black ones for load. For example, white ones are connected to the phase and neutral cables from the panel, and black ones are connected to the lamps;
4. Individual cords can be connected using special terminals or simple winding. Soldering the fastening points is not recommended;
5. After this, you need to turn on the regular key switch and check the operation of the system. If you need to completely remove it from the system, then reinstall the power wires so that they are connected directly to the cotton model.

It is very convenient that you can connect one switch for several lamps; it will control separate groups of devices. After installation, be sure to set the volume control to required level, otherwise the light will light up at the slightest clap or, on the contrary, will not turn on even from a strong knock. Most often, the regulator is a small rotary lever that needs to be screwed to the required level.

Video: features of the device of cotton switches

Price overview

You can buy a cotton switch in any city; the price of the device depends on the brand and its characteristics. Good feedback about Ecosvet, PIC (board 12F683), Claps and Qusun. Let's consider the cost of the Ecosvet-X-200-L model.

This article provides acoustic light switch circuit, thanks to which you will feel in your own home, as if in a luxurious villa - you can turn on and off, for example, the lights... by clapping your hands.

The acoustic switch reacts to single pops and at the same time exhibits low sensitivity to extraneous sounds. Each operation of the device changes the state of the relay, indicating this by the glow of a two-color LED.

The circuit is equipped with an electromagnetic relay with a contact load capacity of 8A/250V, making it suitable for remote control of lighting, blinds, household audio equipment and any other network-powered device.

Once connected to the power source, the circuit will reset and enter a standby state until a popping sound is heard. Consumption, regardless of operating status, is less than 1 W.

Material: ABS + metal + acrylic lenses. LED lights...

The printed circuit board is designed so that the entire device fits into a flush-mounted box with the following dimensions: diameter 54mm thickness 25mm. Due to its small size, the board should fit, for example, into floor lamps or chandeliers without any problems.

Description of the acoustic switch

The system consists of three main blocks:

• sound sensor with transistor amplifier
• T-flip-flop based on 4017 counter
• transformerless power supply

The signal from the electret microphone is amplified by three transistors VT1 ... VT3. The appearance of a strong signal containing predominantly more high frequencies, causes the system to react: positive half-waves of the signal from the microphone cause the opening of transistors VT1 and VT3.

Thanks to the presence of buffer transistor VT2, after the clap, a positive pulse appears at resistor R8, and therefore at clock input 14 of the 4017 chip. It causes a change in the state of the counter, which switches the LED from green to red, and also turns on the relay through transistor VT4.

It should be noted that this circuit uses a transformerless power supply, that is, it does not have galvanic isolation from 220V network. Therefore, extreme care should be taken when setting up and commissioning the circuit breaker.

Series resistor R11 is designed to protect rectifier bridge B1 if the circuit is connected to the network at a time when the amplitude voltage value exceeds 300V.

Without resistor R11, a very large current can flow through the rectifier bridge diodes and uncharged capacitors C5, C6 for a short time, limited only by the resistance of the connections. Resistor R11 limits this pulse to a safe value and protects other electronic components from damage.

To connect the circuit to electrical network Only two connectors are used. The IN connector must be supplied with mains voltage (phasing does not matter).

After the clap and, consequently, the relay contacts close, a voltage of 220V appears at the OUT connector, so a controlled load, for example a lamp, should be connected to this connector.

The entire device is assembled on a two-sided printed circuit board. The low-voltage part of the elements is SMD. After assembly, you need to check very carefully whether all elements are installed correctly and whether short circuit when soldering. An error may result in damaged items. Typically flawless assembled circuit from serviceable elements it starts working immediately.

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The main feature of a sound switch is that they respond to sound. For example, the simplest option is for cotton. That is, a person only needs to reproduce a sound command in order to control the light in a room or even in the entire apartment. A sound switch, or so-called clap switch, is practical and can always pleasantly surprise your guests.

A cotton switch for almost any radio amateur will be difficult to make independently, since it really has a rather intricate design.
To decide whether to install such a high-tech switching device in your own apartment or not, you should first understand what kind of switch it is, what types and features it has.

The range of these switching devices today is quite extensive. This applies not only to species, but also to price categories and some features of individual options. Moreover, there are even designer models that are designed for the interiors of the same “smart” houses.
But, in general, all modern switches are divided into the following types:

• Cotton;
• Acoustic;
• With motion and sound sensor.

The clap switch, as already mentioned, is triggered by detecting the sounds of a certain number of claps.

The acoustic switch responds to a voice or any command. Code phrases can be standard: “turn on”, “turn off”, but some owners of sound models prefer to set their own options, which you definitely won’t shout out by accident. True, devices that support the function of selecting a code word are somewhat more expensive.

The last option from the general range is the most technologically advanced. His the design is designed in such a way as to respond to human movements and his voice at the same time. They exist to avoid common failures, which will be discussed later.

Advantages and disadvantages

The sound or clap switches are quite unique devices in themselves. Their main advantage over standard models is that a person does not need to make an effort every time to turn off or turn off the light. In addition, this can be done from any part of the room.
All the advantages of such switches become intuitively clear from the name alone. Voice and cotton models have been an integral part of any smart home, and a pleasant addition to an ordinary apartment.
Their main disadvantage for radio amateurs will be the difficult-to-reproduce circuit. Still, the design of such devices is much more complex, which means making them with your own hands is far from so easy. If you find and use simple schemes, then this drawback gradually fades into the background.
In addition, the clap switch, like the sound switch, has a number of small disadvantages that will be noticeable to absolutely everyone:

1. They can react to similar sounds, especially the vocal version. Naturally, if you say a code phrase in the context of, for example, a normal conversation, the light in the room will react to it.
2. Minor defects can cause a “slow” reaction in these devices. This often occurs when an acoustic switch, whose design is somewhat more complex, was made by hand. So, you should pay special attention to this factor before you start reproducing any circuits.
3. If the signal - clap or command - is not loud enough, then the device most likely will not respond. The low sensitivity of such switches is needed so that people are less likely to encounter the first problem on this list.

In principle, it is possible to combat these disadvantages, but even a professional is unlikely to be able to completely eliminate them - because if, for example, you increase the sensitivity, the acoustic switch will begin to respond to “false” commands much more often.

Is it possible to make a switch with your own hands?

Only someone who already has at least some experience in working with radio equipment can make an audio switching device with their own hands. For a beginner in this business, it would be best to use the most simple circuits, which are also not so easy to find.
Based on technical data, a standard cotton and acoustic switch operates with the following parameters:

• The network voltage must be 220 (V) - that is, regular one will do incandescent lamp;
• The load power should not exceed 300 (W);
• The room temperature is not lower than -20 degrees, and not higher than +45;
• The sound is adjustable from 30 to 150 decibels;
• Housing protection IP-30.

This is a description of the characteristics for popular model“Ekosvet-X-300-L”, the main emphasis can be placed on them, since this option is ideal for an ordinary apartment.
To make an acoustic switch with your own hands, you also need to look at suitable diagrams. The insides of the device must be reproduced on a separate chip. If you do without much time investment, then it is best to buy whole parts, from which, with the help of a diagram, you can create a working structure.

A sound or voice switch for an ordinary home will not have any features other than a built-in microphone and a slightly different implementation. For those who have already made communication or radio-controlled equipment with their own hands, implementing the scheme will not take much time at all.

Where is the switch installed?

A cotton or acoustic switch created using a microcircuit is best installed on the walls - there. The do-it-yourself option will most likely have a very low sensitivity, unless, of course, you undertake to implement complex schemes.

A voice switch purchased at a special store can be installed anywhere - even on the ceiling. Just before doing this, you need to familiarize yourself with it technical characteristics, and, again, pay special attention to sensitivity. In this case, the rule most often applies is that the more expensive and technologically advanced the model, the greater its functionality.

It is important to consider that a voice or clap switch purchased on a Chinese website for two pennies is unlikely to work properly.
So, in order to save on this purchase, it is better to make it yourself using the necessary parts.

Content: Many modern systems lighting equipped remote control

. For this purpose, remote controls are used, as well as signal-type equipment, for example, a clapper switch. In this case, the push to turn it on and off is a sound of sufficient intensity, approximately equal in strength to clapping your hands. Previously, the assembly of such circuits was carried out exclusively by radio amateurs. Currently, audio devices can be purchased freely at most electrical stores.

Cotton light switch In order to activate such a switch, you just need to clap your hands. As a result, the device will turn on or off. Typically these devices are installed in rooms with minimum level noise - in bedrooms, utility rooms, storerooms, basements, etc. It is not recommended to use cotton switches in noisy places with big amount

people, as excessive noise may reduce the performance of the device. Offices, production sites and workshops are completely unsuitable for installation.

These devices are often confused with acoustic switches. The main difference between them is that the acoustic device is triggered by any noise, and the clap switch is triggered by clap. These devices have proven themselves well in families with small children who cannot reach a regular switch. Now the child just needs to clap his hands to turn the light on or off.

Cotton switch circuit All clapper switches are installed according to a standard pattern, similar to single or. Some models may have their own individual characteristics, but general principles

The switch and lamp operate according to the standard scheme. First, through the shield and distribution box, you need to supply power to a regular switch. The neutral wire from the panel is connected to one lamp or group of lamps. The lamps themselves are connected in parallel with the disconnecting device.

The power circuit going to the key switch must be interrupted and connected to the acoustic device. This operation is very simple due to the small size of the device, allowing installation directly on the lamp body. Therefore, there is no need to install additional grooves in the wall.

Each standard switch is equipped with two pairs of wires - white and black. The white wires are connected to the power supply, that is, to the phase and neutral cables from the panel, and the black wires are connected to the load. It is recommended to connect the conductors using conventional twisting or using terminals. In this case, soldering of joints is not used.

Once the connection is complete, the standard key switch is turned on and the operation of the entire system is checked. If necessary, it can be completely removed from the circuit and the power connected directly to the cotton device. All that remains is to configure the device in such a way as to eliminate false alarms from extraneous sounds.

DIY cotton switch

All acoustic or cotton systems have a microphone, which is used to record sound. In addition, the circuit is supplemented with a time relay or a control power relay. In a standard circuit operating with a voltage of 220 V, the signal coming from the microphone is amplified by transistor T1. Next it passes to the resistance matching unit and the emitter follower of transistor T2. A digital chip is used to assemble the trigger and signal comparator.

The main function of the comparator is to protect the switch from acoustic interference, cutting off long or too short sounds. When the signal passes, the trigger state changes to on or off. Thus, the trigger controls through a thyristor and a power transistor lighting device. A similar circuit can be assembled based on an integrated timer.

Drawing up a diagram will be more convenient if you highlight certain zones on it. They include a transistor microphone amplifier, an on-chip comparator, a trigger, and a transistor that controls a power relay.

You can assemble a clap switch yourself using an Arduino microcontroller. To do this, you will need boards for the sound module, power relay and Arduino Nano. In addition, you will need a computer, a USB cable and a 5-volt power supply. To flash the microcontroller firmware, the Arduino program is installed on the computer.

By changing some adjustment parameters of the sound relay, you can perform it fine settings. Wiring is connected in the same way as in standard circuits. All that remains is to set the protective threshold against false alarms and interference, and the device is ready for operation.

It feeds from a source direct current, voltage from 5 to 12 volts. The parts are available and inexpensive; they can be purchased at any radio store. Personally, I used parts that I soldered from old boards. The circuit is really simple, and even if you have little knowledge of radio electronics, using this article as a guide, you can assemble this device.)

Initially, I found this diagram without any description and of course there was no printed circuit board, so I had to make it myself in order to make the assembly process easier for myself and of course for you, so use it. Download PCB

Acoustic switch circuit:

The circuit consists of microphone amplifier, which is assembled on two KT315 transistors and a power section on a KT3107 transistor (BC557). To increase the sensitivity of the microphone, you can use more powerful transistors, for example KT368 and the like. In the power part, there is also a sufficiently wide selection of analogues; almost any PNP structure transistors are suitable, for example KT814 or KT818, here you first need to look at the power of the power source used.

Below are photos of the necessary parts:

Acoustic switch parts list:

So, first you need to make a printed circuit board. Please note that the printed circuit board has holes for the VD1 diode, since I plan to control room lighting and will use a 12 volt relay as a load. The diode is needed to protect transistor VT3 from the EMF of the relay coil. If you are going to connect a light load to the switch, you can replace it with a jumper.

After making the board, drill holes and tin it. Open the signet in the sprint-layout 6.0 program and looking at the locations of the parts, solder them in place.

Our acoustic switch is ready! Now I want to tell you about a small nuance, the circuit uses a 1.5 kOhm resistor R8, I replaced it and set it to 2 Ohms, since the voltage at the load output dropped significantly and the relay did not work. If you have the same problem, then follow this advice. That's all, share the article below if you liked it.

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