Alexei

A dacha or separate outbuildings in the courtyard of a private house can also become an object of attack by thieves. It is not practical to install an industrial security system in them; it will cost more than all the things stored in such premises.

But you shouldn’t leave it completely without protection; those who like to make money at someone else’s expense, if they don’t take away your property, they will cause damage to the structure of the building, the restoration of which will require funds. Therefore, many believe that the ideal solution would be a simple security alarm; almost anyone can make it with their own hands.

What is included in such a system?

Typically, such models use an IR motion sensor, siren and other components to assemble the device. But since wired detectors are designed to operate from a 220 V network, it will have to be upgraded and converted to 12 V. To do this, a 6 V relay is added to the circuit. Power is supplied to the sensor through a switch. When the device is triggered, voltage is supplied to the relay winding, it is activated and causes the siren to turn on.

If necessary, up to several audio signal devices can be connected to such a circuit. The presence of a regulator in the sensor allows you to set the signal time after the siren is triggered; usually it is no more than 10 seconds. The circuit is turned off using a special device that is switched with a key.

The considered simple security alarm system is one of the most primitive; it is easy to assemble with your own hands and is economical in terms of energy consumption. For example, for the winter you will need no more than 16 alkaline batteries. This scheme works in any conditions and is able to withstand even negative temperatures, so it is quite suitable for installation in an unheated dacha.

Types of homemade circuits

Assembling and installing the system with your own hands has a number of advantages. It allows you to save money and eliminates the possibility of employees of the installation company helping thieves. But the most important thing is that during the manufacturing and installation process you will carefully study the structure of the alarm system, you will be able to troubleshoot problems yourself, make adjustments to it by connecting additional sensors and improve your design.

Watch the video, homemade security system:

There are several ways to equip your home with a simple security alarm, assembled and installed yourself. The first and simplest, but at the same time the most expensive, is to invite employees of a special company who will develop the project, select the necessary equipment, install it and carry out commissioning work. This option is suitable for residential and warehouse premises, but is unsuitable for a summer residence, since the costs will exceed the value of the property stored there.

Another way is to buy equipment, carefully study the instructions for its installation and operation, and perform the installation yourself. In general, there is nothing impossible in this approach.

Moreover, many trading companies are engaged in programming control panels, which will save you from the need to purchase a programmer, study the rules of working with it and try to complete this stage of work without outside help.

For the simplest alarm option, you need to program the device's loops, connect them to a common network and write into memory the required number of keys for access. They will be required to disarm and arm the object. In addition, the switching on of the light device is programmed, with the operating time limited to 10-20 minutes and the relay output for dialing to a mobile phone.

Let's watch the video, an addition to the main alarm using a mobile phone;

On the market you can find many GSM modules for sending a signal to a specified number when the contacts on one of the inputs are closed. These devices are universal and can be connected to any control panel.

If you already have, then the next step is to connect them to the programmed device, which is quite easy for anyone who is able to find the “plus” and “minus” in the circuit. Again, with self-installation, you will be able to understand the cable routing in detail and, in case of a breakdown, fix it without problems.

Watch a video about the purchased GSM system:

For those who are not satisfied with a wired system, you can choose the wireless option. In this case, installation is even simplified, since you only need to hang the sensors in the required places and insert batteries into them. The advantage of such systems is the ability to operate on one power source for up to a year, and their cost, when equipped with one or two sensors, is low.

Detectors also have their advantages. They can be transferred from one place to another, if necessary, without much hassle. The option discussed above can be made cheaper by purchasing used equipment. This option is easy to assemble with your own hands.

Another, cheapest, but also ineffective way is to install dummies. Such a system is unlikely to frighten a seasoned thief, but it can stop boys who decide to play pranks at someone else’s dacha.

Project for a homemade alarm system - is it necessary or not?

Having decided to install a security system in a house, the first thing you have to solve is the development and execution of documentation. A professionally completed project is the basis for the future system, if its installation will be carried out by employees of a special company. But what about those who decided to do all the work themselves?

If you are installing an alarm system in a public place, then the project must be required, otherwise the supervisory services will not accept the system. But a house is not one of these objects, so installing equipment in it will only require a sensor circuit, which is necessary for future maintenance.

The simplest circuits are based on a time relay

We will consider only two of them. The first security alarm for a home that you can assemble with your own hands is based on a time relay. It has two groups of contacts, one of which operates instantly, and the second after 5-10 seconds. This is necessary so that the owner of the facility, upon entering it, has time to turn off the system with a special button, which is installed in a hidden place.

Complete shutdown is performed using a special toggle switch. With this design, a position sensor is installed on the door frame. Before entering, a button is installed that turns the circuit into security mode after the owner leaves. Typically, such complexes use a 12 or 24 V relay.

Watch the video, addition to GSM alarm system, 12 V relay:

The disadvantage of the scheme is that the siren sounds until the alarm is turned off by the button. To eliminate it, the system is supplemented with another relay, the contact response time of which does not exceed 120-180 seconds. After this period, the siren turns off and remains in this position until the security mode is turned on.

The second one offered for self-assembly is based on a single relay. The operating time of the siren is set using a relay. And it goes into standby mode after the system is de-energized. This circuit uses a thyristor to ensure fire and electrical safety of the equipment.

It is designed to connect a large number of sensors for various purposes. For example, for glass, you can use detectors in the form of strips of metal foil that are triggered when they break. Their connection to the common network is performed sequentially.

It is possible to use other types of thyristors. For example, model PEV-10 with a power of up to 10 W or several with a lower rating.

If the circuit breaks, the relay will operate, which will turn on the siren or any powerful bell. Additionally, a light bulb may be included in the circuit, which is an auxiliary element that does not affect the operation of the system.

Is this method of protection reliable?

Property protection is becoming the most pressing issue in our time. And the way to solve it depends on many factors, but cost is often decisive among them.

It makes no sense to install an alarm system whose price exceeds the value of the protected property. For such cases, the ideal solution is to develop and install the system yourself.

But will such an alarm be effective? In some cases, it will certainly be able to scare away thieves, but for reliable protection it is better to use professional equipment and the services of specialists. The use of remote security will not only provide reliable security, but will also allow you to return funds if a robbery is committed.

Modern life is unthinkable without security alarms. They come in a wide variety - for example, fireproof or burglar-proof, and vary depending on the installation location and, accordingly, the required functionality. A country house also needs protection and the best option for it is a GSM alarm system.

Nowadays, there are a lot of companies providing alarm installation services, including those with GSM technology. At first it may seem to you that such systems are extremely complex, but in reality this is not the case. The main thing is to understand a few important nuances, after which you can make an alarm on your own, without resorting to outside help. It will cost several times less, moreover, further maintenance of the security system will depend solely on you. In other words, you will carry out preventative measures and troubleshoot problems yourself.

Despite the fact that GSM alarms are installed mainly in garages, they can also be successfully used to protect a home. The simplest security system described in this article can solve many problems and also add confidence in the safety of your property.

To make your own alarm you will need:

• soldering iron and ability to work with it;
• set of wires;
• wire cutters;
• an old mobile phone (necessarily with buttons - modern touchscreen models will not work);
• single-key switch;
• stationery knife;
• insulating tape;
• small magnet;
• Super glue;
• copper and telephone wires;
• a pair of metal clips;
• multimeter;
• minimal knowledge in the field of radio engineering.

After reviewing the list of necessary tools/materials, we conclude: the cost of a homemade alarm system is low. If you strictly follow the instructions below, the security system will last quite a long time.

Do-it-yourself home alarm system - installation work

In essence, a GSM alarm system is an improved mobile phone. She will call your (or any other) number if someone breaks into your house while you are away.

The idea is this: you need to ensure that the phone itself calls the last number dialed from it at the moment when the front door opens. This phone should always be on charge and lying in some box near the outlet. As soon as the door opens, the invisible contacts installed on the awnings will close and thereby trigger a call from the mobile phone - you will receive a call.

Note! For alarm, you can use the cheapest phone. The notorious Nokia 1100 is ideal for this.

First stage. To begin, cut two pieces about 1.5 cm long from metal clips - these will be hinged contacts on the door. Then take the telephone wire, strip the insulation and unravel it into a pair of internal wires. Solder the ends of each of them to the contact paper clips. Fix the contacts themselves on the door using superglue - one on a fixed hinged hinge, the second on a movable one.

Select the position of the contacts so that they close when the door is half open. Attach the other ends of the wires to a multimeter, then test them in a closed state (with the door open) in order to check the circuit.

Second phase. Route the wires to the place where the device will be located, hiding them under the baseboard.

Third stage. Next, proceed to the phone. It must have a SIM card, a top-up balance, and disabled notifications (such as alarm clock, incoming call, etc.). He must also have the last number dialed to which the call will be made in the event of a hack.

Disassemble the phone, remove the back panel and remove the battery. Then remove the front panel with buttons and gasket. You are only interested in the front part, not the back - on it after removing the keyboard you will see the contact paths. Select the one that leads to the call button (identify it by location, since visually it does not differ from other contacts). Fix one of the copper wires with electrical tape on the semicircular contact, and attach the second to the inner one.

Note! It is very important that the outer contour of the semicircular shape does not close.

Also make sure that the electrical tape does not cover the contact to the end call button.

Fourth stage. When everything is ready, install the battery (you can throw away the case - it is not needed), using the same electrical tape for fastening (it is important that it is blue). After that, turn on the phone. This may seem impossible to you, because the keyboard is no longer there, but here your ingenuity comes to the rescue: take a metal paper clip, straighten it, making a kind of tweezers, and close the contacts under the right button to end the call.

Once the screen has greeted you and the phone has fully booted up, try shorting the copper wires installed in the previous step. If everything is done correctly, the phone will dial the last number dialed. But if this does not happen, you will have to check all the contacts under the button again and repeat the procedure.

Fifth stage. All that remains is to install the phone in the designated place. Connect the copper wires coming from the telephone to the contacts leading from the door hinges. Then connect the charger and plug it into a power outlet. That's it, the GSM alarm system has been successfully installed.

Note! For convenience, you can install a toggle switch on one of the long wires to turn the alarm on/off.

As already mentioned, usually such an alarm is installed on the front door. We advise you to attach the contacts to the internal door between the rooms (it will always need to be closed before leaving). If an intruder breaks into the house, he will in any case move from one room to another and, therefore, open the “alarm” door. After this, a subscriber known to you will call your number and you will be informed about the hack.

Having some knowledge of radio technology, such a security system can be improved to make it look more presentable, and a car alarm can also be made based on it.

An important point that you need to know about

If an intruder enters a house with such an alarm, he will be able to quickly detect it and turn it off. A homemade security system requires a certain time to operate (often a few seconds), that is, to establish a connection with your mobile phone.

If the door closes quickly, the call will be dropped. Remember this.

As a conclusion

An indisputable advantage of such a homemade alarm system is its energy independence. You just need to charge your phone battery in a timely manner using a standard power supply. It is advisable to completely integrate this unit into the electrical network so that the phone is powered by the battery only during power outages.

We also note that today it is more advisable to install a video surveillance system. It has a lot of advantages, but is very expensive, so in most cases people make do with regular GSM alarm systems.

There are many industrial security alarms that you can buy or simply contact a company that installs security alarms in your home or country house. An article for those who don't like to spend money. Homemade security alarm schemes there are also a lot but, basically, they require professional radio engineering knowledge and skills. Here we describe the principle and schemes of the simplest, yet reliable methods and autonomous intrusion protection devices.
The principle itself - upon penetration, a sound and (or) light alarm is activated - an old, proven method that deters thieves in 98%. By the way, not even the coolest alarm system, or even connecting to a security company’s remote control, will protect you 100%. It’s like a car - if it’s ordered, nothing can save it.

But let's not be so pessimistic. Such cases are very rare, especially if you are not an oil tycoon or the like, and you don’t have half your house (dacha) in diamonds, then you definitely won’t fall under the “order.” But ordinary thieves, who commit 99.9% of thefts, will never steal if the light (sound) alarm goes off. It is much easier and safer for them to find and clean out another object that is not equipped with anything - fortunately there are plenty of them and they have a huge choice. From these considerations it follows that it is not at all necessary to spend a lot of money on the purchase and installation of a security alarm, but by making and installing even the simplest, homemade one, you increase the safety of your acquired property, your nerves and your health by many orders of magnitude. The choice, of course, is yours - learn from the mistakes of others; when trouble comes to you, it will be too late.

For the simplest alarm It is enough to install intrusion sensors on doors and windows (a regular reed switch and magnet cost pennies) and connect them to the alarm circuit. The sensor is installed: a magnet on the moving part of the door or window, a reed switch on the non-moving part, so that the reed switch is closed when closed.

All reed switches are connected in series. The alarm will be triggered when the circuit breaks anywhere. Below is a general diagram of such a device.

Here:
I - detector (chain of security sensors),
Op. - siren (sound, light or combined)
P - control relay
VT - transistor (or thyristor)
R - resistor
S - switch for arming/disarming,
Cupr. - relay contacts that control the notification
Kbl. - self-locking contacts
+U - power supply

When the detector is triggered, the warning device is activated. The notification can be light, sound, or combined. In addition, with a little modification, the alarm signal can be transmitted to a remote control, mobile phone, etc.

A transistor is used to invert the sensor signal and does so as follows. While the detector contacts are closed, they close the base of the transistor to the common wire, the base current is zero, and the collector current, respectively, is also zero. When the alarm sensor contacts open through resistor R, the base current opens a transistor that turns on the relay.

You can use a diagram that shows how you can bring the described inverter to banal contacts and eliminate radio elements altogether.

When voltage is applied to the relay through the triggered (closed) contact of the alarm sensor, it is activated, turning on the control. the required system (notifications, data transmission). At the same time, another group of contacts blocks the sensor contacts and, regardless of its further state, keeps the relay in the activated state. You can now turn off the alarm by opening switch S. By closing this switch again, we will turn the alarm system back into standby mode. As you can see, everything is more than simple. However, such a circuit consumes slightly more energy, since the relay coil will be energized in security mode.

A significant drawback of this scheme is that when triggered, it can only be turned off manually. Therefore, such a scheme can be used in the immediate vicinity of a protected object, for example, a nearby garage, barn, etc.

Security alarm circuit with time relay

The basis for constructing the following security alarm circuits a time relay K2 of type RVP72-3-221-ОOU4 or similar is taken, which has two groups of contacts, one of which - K2.1 - operates instantly, and the second - K2.2 - with an adjustable delay ranging from 1 to 180 seconds. The delay is set to 5-10 seconds so that when entering the premises the owner has time to turn off the alarm using the S3 button (installed in a hidden place) before the sound or light signal is activated. Complete disconnection of the alarm system from the network is carried out by switch S1 (toggle switch or any other for 220 V). The door position signal sensor is the S4 button (type KM2-1 or similar small-sized) installed on the door frame. Button S2 is installed in front of the door to the protected premises and it allows you to turn the alarm circuit into ARM mode after exiting. Relay K1 can be used of any type with an operating voltage of 220 V. For safety reasons, it is recommended to use a 12V or 24V relay.

In SECURITY mode, this circuit does not consume electricity, but when the alarm is triggered, the siren (or bell) will sound until the alarm is turned off by button S3 or toggle switch S1 inside the apartment. The same drawback as in the previous scheme.

To eliminate this drawback, the circuit must be supplemented with another short-circuit time relay, illogical to K2 (shown with a dotted line in the diagram). The response time of the KZ.1 contacts is set to a delay of 120-180 seconds. After this time, the alarm circuit will turn off the siren and will remain in this state until the ARM mode is turned on.

In the same way, you can make a simple car alarm yourself.

And another homemade alarm circuit uses only one time relay.

The sounding time of the siren (and/or light) is set in the relay. The circuit will go into standby ARM mode after a short-term de-energization of the circuit, after activation, or upon initial switching on.

S1 - toggle switch to turn on/off the security alarm;
S2 - toggle switch is used to temporarily disable the bell (or siren) while monitoring the operation of the security device

The circuit uses thyristor VS1, which ensures fire and electrical safety. There will be no life-threatening voltage on the security sensor circuit. This circuit allows you to connect many sensors in series to the security circuit. Sensors can be installed on window glass in the form of a strip of metal foil glued around the perimeter. They are triggered when the glass breaks. Naturally, any reed switches will do, in any quantity. All are connected in series into a common signal network. Before arming, check whether the windows are closed. All sensors, except the front door, must be in the closed position.

You can use a similar other thyristor. In this case, you may need to select resistor R1. Resistor type - PEV-10 or similar with a permissible power of 7...10 W. It is also possible to use several series-connected resistors of a lower value.

When the security sensor circuit breaks, relay K2 is triggered (the same as in the previous diagram) and its contacts K2.1 contact the self-blocking unit. Relay K1 is also activated, which will turn off after a specified time (120-180 seconds) by contacts K2.2.

Relay K1 allows you to connect a powerful output load. As a sound source, you can use any siren, for example SS-1 or any powerful bell at your discretion.

The HL2 indicator light and the S2 toggle switch are auxiliary and their use is optional and does not affect the operation of the circuit.

These are the simplest homemade security alarm schemes for a home, cottage or garage that anyone can assemble with their own hands.
Good luck in ensuring the safety of your property.

Russians have always been famous for their ability to do all the housework on their own, without involving specialists. Most men are decently versed in plumbing, electrical, installation work and the structure of a car. Therefore, for many, a DIY security alarm is not a myth, but a reality. Of course, this will require certain skills, knowledge of electrical engineering and the availability of the necessary tools.

Security alarm for apartment

Self installation options In your own apartment there are only two effective security alarms. The first option involves purchasing a ready-made kit, which contains everything you need for a small home alarm system. And if you purchase a wireless system, then you don’t need to do anything. Enough to place sensors in the right places and set up the device according to the instructions. This option has its weaknesses. First of all, the price, which cannot be called too low, then, in some way, you may not be satisfied with the proposed device and security sensors. The proposed equipment may not be sufficient to organize a security alarm in a particular apartment.

Therefore, many prefer the second option, when all components are purchased independently and installation work is also carried out without the help of specialists.

Security alarm equipment

Every security alarm, no matter is it simple or complex, must effectively protect all areas of the apartment and give a signal in case of any violation of the protected area. The main elements of the security system are sensors, each of which reacts to a specific action or event. The number of sensors is limited according to their purpose.

There are only a few varieties:

• Magnetic sensors
• Motion detectors
• Sound sensors
• Vibration sensors

A magnet-reed switch pair is installed on doors and window sashes. When everything is closed, the magnetic field keeps the contact plates in a closed state.

As soon as you open the door or window a little, the magnet will move away from the contact pair and it will open. This is the most inexpensive and fairly reliable sensor included in all security alarm systems.

Sensors

A reliable security alarm system also uses motion detectors, which are triggered as soon as an object is within the detection zone of the sensor. These devices come in different types, but for private security alarm systems, passive infrared motion detectors are used. They are cheaper than radio wave microwave sensors and more reliable than ultrasonic ones. Each sensor has a clearly defined detection zone.

Most infrared motion sensors have a zone length of 10-12 meters and a capture angle of 90 0 .

Typically, such devices are installed according to the principle of one room, one sensor, but there are exceptions. If a room has several windows located on one wall, then an infrared “curtain” detector is installed, which forms a narrow vertical but extended horizontal zone that blocks all windows along the wall.

Sound (acoustic) sensors respond to the sound of breaking glass. They form an additional security line. As a result of installing three types of sensors, the room will be completely blocked and entry into it through the window and door is almost impossible. Vibration sensors respond to attempts to undermine or destroy (break) a wall and are used extremely rarely in household security alarms.

Sirens

In addition to sensors, any security alarm system must have a warning device. Most often, a low-current siren is used, combined in one housing with an LED indicator. Such a device, in case of violation, emits a sharp signal with a sound pressure from 90 to 115 dB, which will simply scare away the intruder. In addition, the sound of the siren along with the red flashes of the LED indicator will attract the attention of neighbors.

Power alarm

For reliable and uninterrupted operation of the security alarm system, care should be taken to ensure proper power supply. Power outages require the use of power supplies with built-in batteries in security systems. Such devices allow the alarm to function normally for several hours.

To perform installation work you will need a wire, cable duct and fasteners. The security alarm is wired using KSPV 4 X 0.5 wire. Two of the four wires are used to supply power to the sensors, and two more form a signal loop. To connect the network, use a ShVVP wire or similar. Installation of sensors and laying of the cable channel is carried out using dowels and self-tapping screws.

PKP - the heart of the security alarm system

The basis of a security alarm system is control panel - PKP. For a simple security system, it is enough to use a device with one or two loops. Such a device is inexpensive, but has well-developed functionality and is perfect for a small apartment alarm system.

Common devices with one loop:

• Quartz
• Astra 712/1
• VERS-PK 1

The cost of the devices does not exceed 1900 rubles. The case of each device has a place for installing a battery. Arming and disarming is carried out using Touch Memory electronic keys, which are included in the delivery package.

Video on how to make an alarm from your phone:

Self-installation of security alarms

Before purchasing everything you need for a security alarm, it is recommended that you complete the entire installation plan on paper. This will help avoid errors when placing sensors and will help determine the exact number of elements required.

To make a simple security alarm yourself, you also need to have the following tool:

• Hammer
• Hammer
• Pliers
• Wire cutters
• Screwdriver Set
• Tester

Choosing a place

First you need to select a place to install the main unit (PKN). Usually it is installed on the hallway wall, next to the front door. It is advisable that an electrical panel or distribution box be located nearby. The device must be in standby mode at all times, so the power switch is usually not installed. Then security sensors are installed, depending on the number of rooms, and a loop is laid. If the apartment is located above the second floor, it is not practical to use glass break sensors. All sensors are included in one loop.

It is easy to check the functionality of magnetic contact sensors using a tester before connecting them to the line. When the door is closed, the circuit is closed, and by opening it 1-2 cm you can see how the contacts open.

Installing sensors

Infrared motion detectors are installed at a height of 210-220 cm in the corner formed by the walls. The specific installation location is selected in accordance with the size and configuration of the room. Such sensors are equipped with a rotating bracket, which makes it easier to select the optimal horizontal and vertical angle.

If the room is small, then the sensor must be oriented so that the window, and if possible, the door, falls into the response zone, which is indicated in the passport. There is a red LED on the body of the motion sensor, the glow of which shows what state the sensor is in. In standby mode, the diode lights up constantly, and when the protected zone is violated, it flashes.

We mount

Installation of a security alarm is carried out using a four-wire KSPV wire, as the design of the apartment or house allows this. It can be laid in a cable channel, under the baseboard and door jambs. After installation has been completed and functionality has been checked, you can choose a location to install the alarm device. A triggered siren will force the offender to abandon his intentions, and will also inform neighbors that something has happened in the apartment or house. The security alarm is controlled using electronic keys, the reader of which is installed next to the device.

Currently, ready-made security alarm kits with . Such innovative devices, if a protected space is violated, can not only notify the owners of unauthorized entry, but also call a quick response service. Of course, the cost of such devices is slightly higher than that of a conventional alarm system, but this is justified by their capabilities.

Video with a non-standard solution for creating an alarm system:

Burglar alarm simulators

A home security alarm made by yourself does not necessarily have to include expensive control devices and sensors. One of the most important things to do at home would be to install a standard motion sensor, which is used to turn on the lighting.

The cost of sensors starts from 300 rubles.

Sensors of this type have a large detection area and can switch a load of up to 2.0 kW, which allows you to turn on a powerful siren and lighting if the protected area is violated. Such security systems are often installed in garages. This is convenient because, unlike complex devices that can be operated under certain conditions, outdoor motion sensors operate over a wide temperature range.

On the security systems market you can already buy ready-made imitators (dummies) security alarms, which can have autonomous power supply. The simplest ones are a regular red LED that operates in pulse mode. In conclusion, we can say that the range of security devices is currently very large, and everyone can choose the best option for themselves.

They diverted a significant sector of the attention of radio amateurs, but not all of it. And even a very universal device cannot cover all cases and niches of our life. And, meanwhile, devices from the last century are still in use. And it’s good that it should be noted that some serve. Well, there are certain difficulties with purchasing parts, soldering modern components, programming, equipment and software for creating programs and flashing them into microcontrollers, knowledge of protocols, error lists, availability of all documentation, etc. And here there are old reliable and familiar methods and, moreover, there are still large reserves of old spare parts that can not be given away for next to nothing, but can be used with much greater benefit.

Burglar alarm circuit

The proposed signaling scheme is based on the principles of the last century, but they serve, along with more modern ones, to this day. After all, they do not require expensive technological devices for their repair and maintenance, and therefore are maintained, relatively cheaply, in working order to this day. The scheme is suitable for protecting a small warehouse, garage, cottage, private house, etc. The circuit uses a good old cable - this is an underwater two-core wire (“noodles”):

TRP cable. TRP 2-0.4; TRP 2-0.5 (TU16.KO4.005-89) - single-pair telephone distribution cables with copper conductors and polyethylene insulation.

Cable PRPPM. PRPPM 2-0.8; PRPPM 2-0.9; PRPPM 2-1,2 (TU U 05758730.009-98) - telephone and radio cables. The PRPPM type wire is designed for operation at a voltage of 380 V with a frequency of up to 10 kHz on telephone lines and distribution networks. A polyethylene sheath is applied to two parallel-laid copper conductors of the PRPPM wire, insulated with polyethylene.

And rupture sensors included in the serial circuit (reed switches, ends, foil, thin wire...), and shock sensors (vibration contact, magnetic reed switch, inertial...).

Inertial magnetic contact sensor DIMK designed to block various structures of protected objects:

• glazed structures for destruction of the glass sheet;
• an attempt to destroy the glass sheet when impacting the controlled area with an energy corresponding to 2/3 of the energy destroying the controlled area;
• an attempt to remove the glass sheet from the fastening structure;
• an attempt to remove window frames with the issuance of an “Alarm” signal to the control panel, concentrator or central monitoring console.

SMK-4E

• Magnetic contact detector.
• Connection: wired, NC contacts.
• Overhead. Under a wooden/plastic door.
• Alarm gap: 10 mm.

Operating principle of the circuit

The alarm is a frightening warning light and sound signal. In short, it works like this:

In case of burglary attempts, impacts, shocks, vibrations of floors, glass, doors, walls, etc. “shock” vibration sensors are triggered. They break the loop circuit for a very short time (milliseconds), to which the circuit reacts with an instant and short-term (about 20 seconds) scaring signal. The effect of this signal will continue until the shocks or actions affecting the “shock” vibration sensors stop.

If a break-in occurs, the alarm will buzz without stopping, periodically disconnecting and connecting the signal (with a frequency of approximately 20 seconds on and 20 seconds off).

When the door is unlocked without breaking into the door, the end switch or reed switch is triggered and the circuit remembers this, it gives from 20 to 40 seconds (adjustable by the alarm user) to reach the secret button and acknowledge or turn off the alarm altogether. If no acknowledgment or shutdown occurs, the circuit will give a signal as if it were hacked.

For example, on a house you can install a sensor for unlocking the front door (magnetic reed switch or end switch), in case of possible burglary attempts, install a thin wire in places where the door may be damaged, or install a “shock” sensor so that a signal is sent before a breakdown occurs. Carry the cable further to the windows, onto which you can stick a thin strip of foil or a very thin winding wire (0.08-0.1 mm) around the perimeter; you can also install a “shock” sensor; if there is a possibility of opening the window without breaking into it, then an unlocking sensor. Also, if it is possible to break into a wall, use a thin winding wire (0.08-0.1 mm), you can also install a “shock” sensor. The signal acknowledgment button can be mounted in the form of a reed switch in the wall not far from the door; you walk in, quickly move the magnet to the desired location and acknowledge the signal. You can also turn off the alarm completely, but it should not be so close and accessible to a burglar. When the power supply is turned off, the circuit can operate from any uninterruptible power supply; its consumption is very low. The signaling device is a different matter, if it is a cricket on a piezocrystal, then the consumption is also insignificant, but if it is a howler and a lamp, then it will be more.

Now specifically about the operation of the circuit itself. The loop is used for two types of control at once:

1 - pre-burglary warning and 2 - post-burglary signaling. They are separated by transmitting a circuit break signal, each with its own half-wave polarity of alternating current. For this purpose, decoupling diodes VD4 - VD15 are installed.

Post-burglary sensors are assembled on the LED of optocoupler U1, and warning sensors are assembled on optocoupler U2. In this case, for each type of control of a sensor/group of sensors (for example, instead of one SFI2 vibration sensor on a window, there can be several connected in series with one decoupling diode) its own decoupling diode is installed. At any break point, both decoupling diodes are installed, even if at a given point there is only one type of control, because Both half-waves of the alternating current period must pass through (for example, VD14 at the “WALL” point). The supply voltage of the loop depends on the length of the loop itself, on the number of control points, on the voltage drop across the diodes - the longer the loop and the more control points, the higher the voltage. And the current of the optocoupler LEDs is set by resistor R13.

The optocoupler transistors are constantly open and discharge electrolytes C1, C7. If the loop breaks when at least one sensor is triggered, the corresponding optocoupler transistor closes and the corresponding capacitor (C1, C7) has time to charge. For clear operation of the circuit, especially for vibration sensors, it is possible to select resistance R7 and capacitance C7, this can set the sensitivity to the force of shock and vibration. Next, the comparators implemented by resistors R2, R4, R8, R9 react, which protect against interference and create a certain hysteresis of the triggers on the elements IC1.1 and IC1.2 first, IC2.1 and IC2.2 second. The IC3 counter reset driver is assembled on element IC1.3. When at least one of the triggers is triggered, the reset on the 3rd leg of the counter disappears and the counting of pulses from the internal generator of this counter begins. The generator is assembled on the internal elements of the meter and on resistor R10 and capacitance C6, which sets the generation frequency and, therefore, the total time of the meter periods. And the discrete time of the warning signal, the delay time of the burglary signal is selected by jumpers on the printed circuit board. Here are the board and schematic files.

An adder of two series of pulses is assembled on element IC2.3

• one series for periodically turning on signals with a duration of half to one second.
• the other series is used to supply pulses of a sufficiently high frequency (about a kilohertz) for supply to a pulse transformer, if it is necessary to switch signaling devices (for example, a howler) operating from a ~ 220V network. If there is no such switching, and the signal device can simply be connected by transistor T1, then the fast series is disabled by a jumper on the board.

The output signal resolution driver is assembled on element IC1.4, and permission will be given when the trigger IC2.1 and IC2.2 fires immediately or when the trigger IC1.1 and IC1.2 fires with a delay. The first trigger (IC2.1 and IC2.2), when triggered, immediately sends an enable signal, and only the counter, having counted a certain period of time (discretely set by jumpers on the board), will reset the trigger, and the trigger will inhibit the output signal. The second trigger (IC1.1 and IC1.2) only removes the reset from the 3rd pin of the counter, which, after counting the delay (the delay time is discretely selected by jumpers on the board), sets the resolution (logical unit on pin 4 or 5 of the counter) to the output signal. Element IC2.4 is output; if there is no resolution to the output signal, it generates a log. zero and locks the output switch on transistor T1.

Power supply and signaling devices

The circuit is powered by a stabilizer on the zener diode VD1 and resistor R5, implemented on board 1. The rectifying bridge VDS1 and the smoothing electrolyte C5 of the circuit power supply are implemented on board 2. Where the switching device is also implemented on thyristor T2, pulse transformer Tr1, bridge VDS2 and resistor R11. Signaling devices can be different: howler for ~220V; bell at ~220V; lamps; with a piezoelectric crystal generator; from car alarms; even a ringing device from a telephone on a piezocrystal (if you do not need high sound power). Especially for the site - PNP NPN.

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