DIY air raid siren with two transistors - photo | With your own hands

A siren is used for sound notification of any process. As a rule, a siren is heard when an alarming event occurs, but radio amateurs use such sounds in various alarm devices. The tone and frequency of such a sound will force attackers to abandon their bad intentions.

By assembling the siren, we have another goal - to improve skills and experience in the development of electronic devices. Since this siren circuit is quite simple and even a novice radio amateur can do it, we will consider in detail the purpose of all elements of the circuit.

Making a siren from a speaker

So, take a long screw with a square nut. You can also use a regular nut. We take the wire, strip it and wrap it in a nut or screw, there is not much difference.

We glue it to the speaker body, to the magnet specifically, along with the wire. Two-component resin or “cold welding” are ideal for this.

Everything is installed in such a way that the bottom of the screw touches one of the flexible wires going to the diffuser.

Solder the second contact to the opposite terminal.

We connect a power source with a voltage of 1.5-9 V. A 3.7 V battery from an old mobile phone will do. Carefully rotate the screw until you hear a persistent siren sound.

The siren is working. If nothing works the first time, change the polarity of the power source.

Lada 2109 › Logbook › Quick change of alarm sounds aka Talking FLASH siren. RESTYLING 4

The purpose of this device is to change the standard beeps and the monotonous siren sound that is the same for everyone, with your own unique sounds, thereby highlighting and personalizing your car.)))

What can he do? Its technical parameters and design advantages.

Allows you to decipher 10 pulses (inclusive) from the alarm, plus a constant level.
This allows you to replace such operational alarm sounds as: * Alarm sound.
* Alarm disarming sound. * The sound of arming the alarm if the door, hood or trunk is open (if, when arming the alarm mode, any of the sensors is active, a separate event occurs with a separate sound for it).
* The sound of disarming, the siren was triggered
(if during your absence there was an attempt to break into the car, which caused the siren to trigger, then when disarming, a separate event occurs with a separate sound for it).
* Shock sensor sound (shock sensor).
* Siren sound (panic mode). * Car search sound. * Sounds of 7, 8, 9, 10 pulse events (if the alarm supports extended pulse events, you can also replace the sounds of these events, each event has its own separate sound).

There is also a separate PRO channel, independent of the alarm system, the sounds of which can also be changed by replacing WAV files. * Short level sound BIBIKA PRO channel

(sound is played in full).
* Constant level sound BIBIKA PRO channel
(sound is played as long as there is a signal).

All sounds are WAV files, 8/16 bit, mono/stereo format, sampling frequency up to 48 kHz. Windows PCM.

If there is no microSD card in the slot, then the operation automatically switches to the normal operating mode and the siren operates as a standard multi-tone siren. Also, if there are no files for individual events or the format of the sounds was mixed up during replacement, they are also automatically replaced with standard sounds. I'll tell you in more detail how it works. The sounds of the standard alarm (beeping and the multi-tone siren itself) are built into the controller itself at the firmware level, and do not require a microSD card in the slot for playback. Thus, without a FLASH card, the siren is fully operational and its operation and sounds are completely the same as the standard one. If we insert a card into the FLASH slot, then the sounds are taken from the card and replace the standard ones from the firmware. This is very convenient when replacing sounds. Since the slot is located outside the siren and the FLASH card is a regular microSD card, it becomes possible to change sounds with one click even from a home PC, even from a regular mobile phone, smartphone, player, laptop, tablet, camera, or in general from anything, anywhere There is a slot for microSD cards. At the same time, THE CAR IS ALWAYS UNDER PROTECTION! This is also convenient if there is a need to set up an alarm. Since setting up alarms (ON/OFF functions) is carried out by pressing the valet service button and counting the number of peaks, to set it up you just need to remove the microSD card from the slot and you can start setting up the alarm. During alarm setup, all peaks will be played.

Protection systems.

The device uses a powerful 22-Watt low-frequency amplifier, PHILIPS brand. This branded amplifier itself has a temperature protection system and protection against short circuits in the load. This has a beneficial effect on the protection of the audio channel and on comprehensive protection in general. Since the amplifier is two-channel 2x22W and only one channel is used, that is, there is a prospect for the development of the audio channel. You can always connect it to something else or use it as a backup. Essentially, these are two separate, independent amplifiers in one housing.

How to make a siren with your own hands - instructions

All the necessary details on how to make a siren with your own hands are shown in the photo. Both large and miniature speakers will serve as speakers. To power the siren, a 9-volt Krona battery will do.

Any button (I took it from a laser pointer). Resistors can be of any power. Electrolytic capacitor C1 must be designed for a nominal voltage of 16 V.

Transistors

The location of the contacts of the transistor KT315 and KT814 is shown in the figure. When assembling, it is necessary to correctly connect the contacts (base, collector and emitter) of the transistors, as shown in the diagram and figure.

Otherwise, the transistors may fail. The letter index can be anything.

Assembly

As contacts for the device, I used copper wires with insulation 30-40 cm long. The ends of each wire were stripped and treated with rosin and then with tin. We are slowly assembling according to the diagram, soldering prepared wiring to each part. It is worth noting that you should not overheat the transistors, as this will lead to malfunctions. The electrolytic capacitor must be soldered as shown in the diagram (there will be a + or - sign on its body near the side contact).

The principle of operation of such a siren with your own hands: when you press the button, the sound frequency increases, when you press it, it decreases. The diagram shows that even with the contacts open, the circuit is connected to power (the crown is slowly discharging). This can be corrected by connecting an additional switch.

This is what a homemade siren looks like after everything is soldered correctly. In this case, I connected a miniature speaker (see photo). Such a siren will not be very loud, but absolutely compact. The case for such a device can be used small.

When connecting a speaker of higher power and larger size (see photo), the siren with your own hands will be quite loud. For such a siren it is necessary to find a larger housing.

If you want to use the siren as an alarm or doorbell, instead of the crown it is advisable to connect a power supply with a DC output of 9 to 12 volts.

Good luck with your DIY siren assembly!

See also how to make an electronic flasher with your own hands

Personal security siren diagram

Figure 2 shows a diagram of a personal security siren. The siren turns on when the contacts of the SB1 button are briefly closed. The circuit can also use the SB2 button, when pressed and held for more than ten seconds, the siren is activated and turns off only after 2...3 minutes.

Switch SA1 sets the character of sound signals: from periodic howling to two-tone sound bursts. In standby mode, the device consumes virtually no energy, so it does not require a switch.

You can reduce the output power if you exclude the powerful transistor VT2 type KT805 from the circuit, while the volume of the sound signal and the current consumed by the device will decrease several times. In this case, it is advisable to connect the loudspeaker through a transformer. You can use a radio broadcast speaker.

Rice. 2. Schematic diagram of a homemade siren for personal security.

How to make a motor siren, manufacturing process:

We cut off the bottom of the pipe plug, and cut out six identical rectangular holes in a piece of pipe:

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

Using a Dremel, we make 6 petals in a tin can, as can be seen from the photo:

Powerful motor siren made from a tin can and PVC pipe

We bend the petals inside the jar.

Powerful motor siren made from a tin can and PVC pipe

We cut square blanks from the same PVC pipe, you need 12 pieces, glue them together with superglue, 2 pieces each:

Powerful motor siren made from a tin can and PVC pipe

Next we glue these square pieces between the windows inside the 100 mm tube:

Powerful motor siren made from a tin can and PVC pipe

Next we need an electric motor; we put the bottom of a plug for a PVC pipe on its shaft; as you can see, I made the necessary holes in it for mounting to the motor.

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

We cut out a boss from a piece of wood, drill a hole in the center of it for the motor shaft, it should fit tightly onto it, and 2 blind holes are made at the bottom for screws to attach the boss to a tin can.

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

We screw the wooden boss to the tin can, and then put this structure on the electric motor shaft, and then forcefully insert a piece of tube with rectangular holes into the plug from above.

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

Now turning on the motor siren, the electric motor with a tin can quickly spins up, the air flow that is blown out and hitting the walls of the PVC tube creates such a powerful roar, and when using the siren as a security system, it will quickly scare away anyone who entered the room, because it is so loud and the soulful sound of a homemade motor siren will attract the attention of people around you. See our other crafts and DIY projects on our website.

Powerful motor siren made from a tin can and PVC pipe

Powerful motor siren made from a tin can and PVC pipe

See an example of how this motor siren works in the video:

Features and application of the security system

Country cottages and private houses need protection, since neither locked doors nor strong walls can save them from thieves. In addition, dachas and similar real estate properties always stand apart, at a relatively large distance from nearby buildings. Therefore, neighbors may not see the intruders breaking into the house, which means that law enforcement agencies will not be called in time.

A private house attracts thieves more than an apartment

A private home lacks such protection as an electromagnetic lock at the entrance and an intercom at the entrance door, which is why it requires the organization of a security system. The decision on its design, which protects housing from thieves, should be made taking into account the service area of ​​a private security company.

Intercom connection diagrams are presented here:

An alarm system for a country house or cottage is a complex complex that includes devices with various protection methods, depending on the channels. The security system is a combination of sensors, a control panel and actuators.

In addition to the motion sensor, siren and red lamp, you will need a reader with keys

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How the alarm works

Depending on the type of communication channel, the alarm can be wireless, when the signals are received via a GSM network, or wired, characterized by the laying of wires throughout the house. A security system of any type operates thanks to a connection to a 220 V power supply or an autonomous backup power supply, which does not allow the devices to stop working in the event of a power failure.

An alarm system allows you to control your home

The principle of operation of a security system with a siren can be represented as the sequential implementation of special operations. It all starts with a sensor that controls the opening of doors or windows, reacts to movement in a certain area or glass breaking. This device is triggered and sends a signal to the control panel.

Motion sensors are installed in a place where they can monitor a certain area of ​​the home and signal the movement of objects. And devices that inform about thieves entering through a window are mounted near the frames. Such sensors react to glass breaking. This or another alarm signal is received by a control panel or board enclosed in a panel and connected to all sensors.

Devices that detect movement, glass breaking, and door opening can be used at the same time.

Next, information about the break-in is transmitted to the actuator, which can turn on the light or sound, or warn the owners of the house about the trouble with a voice message on the phone. In another case, the security company employees receive an alarm signal from the actuator. A call about an intruder breaking into a house reaches them in a matter of seconds.

Employees quickly go to the place where the alarm went off

Only the owner of the house is responsible for turning off the system, who needs to press a special code to stop the siren. The alarm is always controlled using a remote control or keypad connected to the board.

Security alarm based on motion sensor

The simplest security alarm for a home can be made with your own hands based on a conventional household motion sensor for lighting, which is installed in entrances to save energy. But instead of a lighting lamp, you can install a siren.

What will you need for this?

• Motion sensor - you can buy it at any hardware store, for example OBI or Leroy Merlin. It is necessary to pay attention to the operating voltage of the sensor - we need it to operate from a 220V network; the viewing angle depends on the external design of the sensor (wall-mounted or ceiling-mounted) and the lens used (can be wide 180 degrees or corridor type). Average cost from 400 to 800 rubles;
• Siren operating from a 220V network . For example, PKI-3 “Ivolga-220”, average price 250 rubles. Can be purchased at radio stores;
• A regular switch to turn off the alarm. Any will do, from 100 rubles. and higher.

The connection diagram is shown below:

You need to choose a motion sensor that has at least two types of adjustments - time adjustment (TIME) and sensor sensitivity (SENS). Using the first one, it will be possible to set the activation time of our alarm, i.e. siren sounding time. This value is usually set for five minutes. The second adjustment changes the sensitivity of the sensor, for example, if it does not respond to you or to reduce so-called “false alarms”.

A switch will be needed to turn off the device when you are in its field of view and turn it on when you leave the room. It is advisable to install the switch covertly, so that after activating the security alarm you will not fall within its range of action. In addition to the siren, you can also connect a regular light bulb for double impact on the intruder.

The main disadvantages of this implementation will be that some models of motion sensors, after being turned on, require from 1 to 10 seconds to “stabilize” and switch to standby mode. If you come across such a sensor, you need to add a time relay to the overall circuit, which will keep the siren turned off while it is turned on.

There are also miniature motion sensors on sale that operate on 12V, for example, model DD-03. You can also create a simple alarm on them, but you need to connect it to a 12 volt power source or a battery. Thanks to this, the system will be non-volatile and work even if there are power outages.

Security device with light and sound alarm

Security devices with intermittent light and sound signaling (Fig. 6, 7) are made using generators based on analogues of injection field-effect transistors [Ra 6/00-27].

Rice. 6. Schematic diagram of a simple security device using two transistors.

In the first of the devices (Fig. 6), the security alarm loop B1 is connected in parallel with the emitter-base transition of transistor VT1. If the loop is in good condition, transistor VT1 is closed, the device consumes a current of no more than 20 μA from the power source. If loop B1 is broken, the pulse generator on transistors VT1 and VT2 will begin to synchronously produce short ringing bursts of sound (BF1) and bright flashes of light (HL1).

The average current consumed by the device in alarm mode is 2 mA at a repetition rate of light and sound messages of 1...3 Hz. Resistor R2 determines the frequency of light and sound transmissions - from continuous sound and glow to fractions of Hz.

Advantages of using a system with a howler

The main advantage of installing an alarm system with a siren is the immediate psychological impact it has on intruders. A security system that responds by turning on the light when strangers enter the house is not capable of frightening vandals, drug addicts, or migrant workers. And loudly blaring sirens on the street cause criminals to be in a state of shock and want to quickly escape from the scene.

The signal can be transmitted to several points at once

The bell of the security system is triggered by sensors detecting movements in any area of ​​the local area. Devices that signal the siren to sound can be installed both inside and outside the house. The duration of operation of the howler is selected during installation of the alarm and can range from 3 to 10 minutes. The sound of the siren is always complemented by a flashing light indicator, which, in a calm environment, lights up continuously.

Is the use justified?

Usually, dacha owners are upset by the operation of the alarm system if it is Chinese or cheap. In this case, a false alarm of the siren or “loss” of sensors by the control unit occurs. However, this problem can happen to any electronic device.

Despite complaints from some alarm users in their dachas, there are also positive things being said about the use of a security system. The howler and other alarm devices really save the house from intruders: they put psychological pressure on thieves, quickly send a signal to special services and urge neighbors to contact the police. Also, as owners of real estate connected to an alarm system note, sensors and other devices are easy to install themselves.

Causes of system malfunction

The alarm may not work or turn on randomly if the following errors were made:

• taking preliminary measurements by inexperienced persons;
• selection and installation of the device, as well as laying of wires without taking into account various factors;
• deviations from the rules when drawing up a project;
• incorrect location of alarm elements;
• negligent work on installation of system devices;
• installation of an alarm system without a technical passport;
• damage to elements of the security system or failure to use electrical wires;
• deviation from the alarm maintenance instructions.

Criteria for choosing an alarm system with a siren for a summer residence

When looking for devices that protect a country house from thieves, you need to proceed from certain rules.

What factors are most important?

The choice of security system is determined by the following factors:

• living conditions, because they can live in a private house both all year round and only in the summer;
• location of the property on the site;
• the distance of the dacha from the place of permanent residence or security company;
• the value of the property located in the house and buildings in the surrounding area;
• finances that the home owner is willing to spend on an alarm system;
• relations with immediate neighbors.

The choice of alarm is greatly influenced by the distance of the dacha from the house. If the suburban area remains empty throughout the winter, then you should purchase equipment that will not fail at low temperatures.

To protect property in a private home, it is recommended to additionally install a video surveillance system. Features of video camera installation are studied in detail in this material:

The owner of a dacha who does not maintain friendly relations with his neighbors is better off installing an alarm system that will notify the security service about a crime. Otherwise, valuables may be lost, and the thief may not be caught, because the trip to a remote property may be long.

Table: signaling options