home Household

Sound switch for an ordinary home: is it necessary? Turning the light on and off with a clap: self-installation of the device Algorithm for the functioning of the acoustic switch

It is powered by a DC source, 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 circuit without any description and naturally 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 a microphone amplifier, which is assembled on two KT315 transistors and a power section on a KT3107 (BC557) transistor. 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.

We have a channel on Yandex.Zen: DIY and electronics

Buy an acoustic switch, kit for self-assembly:

An acoustic switch is quite an entertaining and interesting device, which is very useful to assemble for a novice electronics engineer or radio amateur to improve their skills. Let's look at how to make an acoustic switch with your own hands from available radio elements.

The principle of operation of such a device is that a sound signal, usually a clap of the hands, is perceived by a microphone, after which the load is connected or disconnected using various circuit solutions. Most often, the load is an incandescent lamp or an LED lamp.

How does an acoustic switch work?

The operating algorithm of the simplest acoustic switch looks like this: when a clap is heard, the lamp turns on, with the next clap it goes out, and this repeats all the time. In this case, the light bulb can remain in any state indefinitely. We will assemble a more advanced device.

The first operating algorithm of our acoustic switch functions in this way: one clap - one lamp lights up, the second - the second, the third - the third, the fourth - all the lamps go out. Then everything will happen again.

The second algorithm - everything happens in the reverse order: the first clap - three lamps turn on, the second - one goes out and two lamps remain on, the third - one lamp remains on, the fourth - all the lamps turn off. This option is well suited for a “night light”, since with each clap the light becomes dimmer and then goes out.

Acoustic switch circuit

There are a huge variety of acoustic switch (AS) circuits: on transistors, logic chips, flip-flops, etc., but we will assemble our device on a microcontroller. Using a microcontroller, you can quite simply implement algorithms of varying complexity with minimal circuit modification or no modification at all.

The first and integral element of any acoustic switch is a microphone. The microphone converts the audio frequency signal into alternating voltage. The simplest electret microphone will suit us.

One terminal of the microphone is connected to the negative, and the second, through a trimming resistor R1, with a resistance of 510 kOhm, to the positive. Using R1, you adjust the microphone sensitivity. Next, the alternating signal from the microphone output through a 1 µF separating capacitor C1 is fed to a transistor made on a single BC547 transistor. The emitter of the transistor is connected to the minus, and the collector is connected to the plus through resistor R2, with a resistance of 1 kOhm. The amplifier is adjusted using a tuning resistor R3 with a resistance of 1 MOhm.

Next, the amplified signal is fed to the input. Depending on the number of received pulses, which corresponds to the number of claps, the microcontroller outputs a high or low potential to the corresponding pins. In this circuit, we use three pins of the MK microcontroller, which operate as output. They feed three similar circuits. Let's consider the operation of one circuit.

When there is a high potential (+5 V) at the MK output, transistor VT2 of the 2N2222 series, connected to the MK by resistor R4 (1 kOhm), opens and relay coil K1 receives power. When relay K1 is triggered, its contacts close in the lamp power circuit and thus it lights up.

The relay coil K1 should be shunted with a reverse diode VD1 to protect against overvoltage, since the coil has some inductance, and if the circuit breaks, a voltage surge may occur, although not significant in this case, but it is better to be safe. Almost any diode with a current of at least 100 mA will do; you can use 1N4148.

Any relay can be used, but you should focus on the following parameters: supply voltage 5 V, voltage of the closing contacts - alternating, 230 V. The contact current is determined by the load of the circuit that the contacts will close and open. I used the following type of relay: HW32-005VDC-A. If you find a relay with a coil supply current of no more than 20 mA, then you can do without a transistor switch.

The acoustic switch circuit is powered from a stabilized power source with a voltage of 5 V. You can take any ready-made power supply or assemble it yourself, as described in.

Setting the acoustic switch

The device is configured using two variable resistors. I achieved such sensitivity that the switch did not respond to music, speech and light door knocks, but at the same time it worked perfectly when there was a clap from the opposite end of the room. Please note that the microphone must be positioned in the direction of the clap.

You've probably wondered why cotton? The fact is that the amplitude of the sound wave caused by clapping is much greater than during a normal conversation or music, so the amplifier can be configured in such a way as to filter out other sound sources, thereby eliminating false triggering of the device.

Now, I hope you are convinced that making an acoustic switch with your own hands is quite simple. I assembled this device on a breadboard, but if we use SMD components and solid-state relays, the size of the acoustic switch will not exceed a matchbox. Happy assembly everyone!

Download

The circuit diagram for this acoustic switch was found on one of the bourgeois sites. After checking, it became clear that the circuit was not working, after some experiments and alteration of the circuit - lo and behold! she earned it!
Almost all the values of the components used were changed to make the circuit more accessible to beginner radio amateurs, and this is the end result.

Perhaps this is the simplest circuit that can exist; it uses a minimum number of components that are available to everyone. As a result of the alteration, domestic parts were used, which greatly facilitates the selection. The microphone was taken from a Chinese tape recorder; you can also use domestic ones, such as pine.

The microphone amplifier is assembled on two KT315 transistors, but to increase the sensitivity of the microphone it is advisable to use transistors like KT368 or its imported analogues; in general, transistors are not critical.

The power part of the circuit is a powerful bipolar transistor that controls the load, and in order to control large loads a relay was used (12-24 or 220 volts).

The signal from the microphone is amplified and sent to the base of a powerful key, the transition opens and it is at this moment that the relay is triggered, the microphone reacts to loud sounds (for example, clap), the sensitivity of such a circuit is 4-5 meters. At the second clap, the circuit is automatically switched off, therefore, the supply of current to the load is stopped.

The capacitors are electrolytic, the voltage is not so important, you can use the appropriate capacitors with a voltage of 10, 16, 25, 50 volts.

The range of supply voltages is also quite wide - from 3.5 to 14 - 16 volts, the current consumption in idle mode (when the circuit is turned off) is practically zero. The circuit can be assembled either on a breadboard or by surface mounting; the values of the parts are not critical and may deviate in one direction or another by 20%, but try not to replace the capacitances of the capacitors used, since the best parameters are obtained with the capacitors indicated on the diagram.

List of radioelements

Type	Denomination	Quantity	Note	My notepad
Bipolar transistor	KT315A	2		To notepad
Bipolar transistor	KT818A	1		To notepad
Rectifier diode	1N4007	1		To notepad
Electrolytic capacitor	1 µF	2	10-50V	To notepad
Resistor	10 kOhm	2		To notepad
Resistor	3 MOhm	1		To notepad
Resistor	48 kOhm	1		To notepad
Resistor	1.8 kOhm	1		To notepad
Resistor

An acoustic switch is a very useful and necessary thing in the household, especially if you want to automate some devices or lighting in your home and add creativity to your home! Using an acoustic switch, you can turn the lighting off and on or use it for other devices, such as an electric kettle or fan.

This scheme is fully operational, streamlined and stable. There are many diagrams of similar devices on the Internet, but when assembling them, a lot of performance problems arise and some of them lead to long discussions at the end of which, the problem is often not solved. Below is the diagram itself.

The circuit is powered by a voltage of 5 to 9 volts, so choosing a power source will not be difficult. You can use, for example, a crown or other batteries and accumulators. If you need stationary power, then there are many power supply circuits online, even a transformerless one will do.

The printed circuit board is made for DIP components, but despite this, it has quite compact dimensions and choosing a housing for it will not be difficult. You can download the printed circuit board from the link:

(downloads: 726)

List of parts for assembly

PCB manufacturing

I will not explain in detail how to make a printed circuit board, as it will take a lot of time. The PCB file is opened using the sprint-layout 6.0 program:

(downloads: 612)

The circuit uses diode VD1; it is needed to protect transistor VT3 from the EMF of the relay coil. If you connect a relay as a load, then you need to install a diode; if you use a light load, then you can install a jumper instead.

After making the board, to avoid oxidation, tin the thresholds with tin. Open the sprint-layout 6.0 program and solder all the parts on it according to the location. If everything is done correctly, the parts and values are not mixed up, then the device should work immediately without any problems.

This is what the assembled acoustic switch looks like.

And another photo with a connected battery and an LED on the load.

I would like to tell you about one problem that may arise. The circuit contains a 1.5 kOhm resistor R8, if you use an LED as a load, you can leave it, if you plan to install a relay, then replace the resistor with a 2 Ohm. There shouldn't be any more problems))

The result was an inexpensive but very effective and useful device that will definitely find its use in the household!))

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 types, 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.

By the way, not all circuits of this particular model are difficult to reproduce with your own hands, so any radio amateur can try to make this device. 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. Throughout their existence, 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:

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.
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.
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 simplest 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 mains voltage should be 220 (V) - that is, a regular incandescent lamp will do;
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 the 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. A do-it-yourself option will most likely have very low sensitivity, unless, of course, you undertake to implement complex circuits.

A voice switch purchased at a special store can be installed anywhere - even on the ceiling. Just before this, you need to familiarize yourself with its 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.