How to make an alarm out of the box. Simple do-it-yourself alarms. PKP - the heart of the burglar alarm

This article provides diagrams of the simplest electronic alarms, which can be done by anyone who is at least minimally familiar with electronics or simply knows how to hold a soldering iron in his hand. Such alarms come in handy in many cases. They can be put on the windows if there is a small child in the house who can open them. On the doors of an apartment or garage of a guarded parking lot. And when triggered, the watchman will call the police. You can put such an alarm in the apartment if you are friends with your neighbors. Even if you go camping, it’s not a sin to spread a security train around the camp at night in case of wild animals or strangers.

First scheme electronic signaling is simple to the extreme, there is nowhere easier. This is just one transistor, a resistor and an executive relay. If an audible alarm is expected, then instead of a relay, an audible siren or howler is turned on.

Principle of operation: A security loop is a thin wire, or a closed contact. When the wire is intact (or the contact is closed), the base of the transistor is grounded and the transistor is closed. No current flows between collector and emitter.

If you break the security wire, or open the contact, the base will be connected to the power source through the resistor R1, the transistor will open and the relay (or siren) will work. You can turn it off only either by turning off the power, or by restoring the security loop.
Such an alarm can be used to protect your belongings, for example. A reed switch is used as a security contact, the alarm is hidden in the side pocket of a bag or backpack, and a magnet is placed nearby. If the magnet is removed from the alarm itself (move the thing), the siren will squeal in all voices.

Second scheme with more advanced user features

As in the first case, a security loop, a normally closed (in armed mode) contact or a reed switch closed by a magnetic field serves as a sensor. If the loop is violated, an alarm is triggered and its operation continues until the power is turned off. Restoring the loop does not turn off the alarm, it will still continue to work for some time. The alarm has a button for temporary blocking, which is necessary for the owner to leave the protected area. The alarm also has a response delay, which is necessary for the owner to turn it off when he enters the protected area.

Let's analyze how the circuit works. Before arming the alarm, it is necessary to turn off (open) switch S1. It must be installed in a secret place near the entrance. You can use, for example, a hidden reed switch, which closes - opens by rearranging some object with a magnet built into it, etc. This switch blocks the operation of the system and it stops responding to a broken loop. When leaving, the switch S1 opens and the capacitor C2 begins to charge through the resistor R2. Until the capacitor is charged to a certain value, the system is "blind". And you have time to leave the object, restoring the security loop or closing the contacts. By selecting the values of resistor R2 and capacitor C2, achieve an acceptable output delay for yourself.

If the security loop is broken, then the capacitor C1 will start charging through the resistor R1. This pair creates a slight delay in the alarm, and the owner has time to neutralize it by turning on switch S1. It is necessary to choose the values of the resistor and capacitor for a comfortable response delay time.
If the loop is broken by an intruder who does not know how to turn off the alarm, then some time after the loop is broken, the alarm will work (at both inputs of element D1.1 they will be logical "1", respectively, at the output "0". After passing through the inverter D1 .2 it will again become "1" and open the transistor VT1. The transistor will discharge the capacitor C3 and open the transistor VT2 through the inverter, which will make the executive relay work or turn on the siren.

Even if the attacker quickly restores the loop, the siren will continue to work, since the capacitor C3 will charge through the resistor R3 for a sufficient time. It is the ratings of this pair that determine the operating time of the alarm after the loop is restored. If the loop is not restored, the alarm will work constantly.
Chip - K561LA7, transistors - any n-p-n (KT315, KT815, etc.) Power supply - any with a voltage of +5 - +15 Volts. The executive relay or siren can be connected to a more powerful power source than the circuit itself. In standby mode, the circuit consumes practically no current (at the level of self-discharge of batteries).

The Electronoff.ua online store presents another video from the DIY Smart Home series, How to Make an Sound Alarm.
The system is very easy to make yourself. To do this, you need to collect only two constructors.
Today we are assembling a sound alarm - a device that will prevent crooks from entering your home!
To implement the entire project, we need two Constructors:
sound siren and
infrared barrier.
In addition, we will use
soldering iron with temperature control YIHUA928D: https://goo.gl/ZP2ibL,
solder^ https://goo.gl/gMkfZe
and flux: https://goo.gl/PVBqYQ.
The additional tool "Third Hand" will help a lot in your work: https://goo.gl/mn8P5j.
He fixes the board, thereby freeing the hands of the master.
The structure of the constructor "Sound alarm" includes a speaker, a board, instructions and electronic components to be soldered.
Traditionally, let's start by soldering the microcircuit. For its correct placement, both on its case and on the board there are appropriate designations.
For greater convenience, we fix the board in third parties. To make the soldering better, we will apply the flux before starting work.
We insert the microcircuit and solder its conclusions on the back of the board.
After that, you can proceed to the rest of the elements. The instructions have a complete list of them with the appropriate designations.
The value of the resistors can be found using a multimeter, as we did in previous videos. And you can use a special application for your smartphone. By choosing a certain color, you will find out the value of the element.
Solder the components according to the instructions.
If you soldered the element incorrectly, it can be easily removed with absorbent tape.
When soldering transistors, it is necessary to adhere to a special layout of the board. On it, the transistor must be inserted according to the pattern and its shape.
After we assemble all the components on the board, solder the speaker. For this, we have prepared a wire.
The sound alarm is assembled.
To check its operation, you need to connect the power. We will use the BAKU BK-350D power supply. We touch the probes to the contacts of the circuit.
The alarm is working.
Is there sound! Half done!
In the next video we will make an infrared motion sensor. He will set off the alarm and make the thieves run away in panic!

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The 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, electrics, installation work and in the device of the car. Therefore, do-it-yourself burglar alarms, for many, are not a myth, but a reality. Of course, this will require certain skills, knowledge of electrical engineering and the availability of the right tool.

Security alarm for an apartment

Self installation options in your own apartment there are only two effective burglar alarms. The first option involves the purchase of a ready-made kit, which has everything you need for a small home alarm. And if you purchase a wireless system, then you do not 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, for some reason, the proposed device and security sensors may not be satisfied. 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 kit

Every burglar alarm, no matter is it simple or complex, should effectively protect all premises of the apartment and give a signal in case of any violations of the protected area. The main elements of the security system are sensors, each of which responds to a specific action or event. According to their purpose, the number of sensors is limited.

There are only a few varieties:

Magnetic sensors
Motion detectors
Sound sensors
Vibration sensors

A pair of "magnet-reed switches" is installed on doors and window sashes. When everything is closed, the magnetic field keeps the contact plates closed.

It is worth slightly opening the door or window, as 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 burglar alarm scheme also uses motion detectors that are triggered as soon as an object enters the detection zone of the sensor. These devices come in many types, but PIR motion detectors are used for private burglar alarm systems. 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 - one room - one sensor, but there are exceptions. If there are several windows in the room on the same 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 react 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 penetration into it through the window and through the door is almost impossible. Vibration sensors react to attempts to dig or destroy (break) the wall and are rarely used in domestic security alarms.

Sirens

In addition to sensors, any burglar alarm 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, gives a sharp signal with a sound pressure of 90 to 115 dB, which will simply frighten off 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, you should take care of the correct 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 wire, cable duct and fasteners. The wiring of the security alarm is carried out with a wire KSPV 4 X 0.5. Two of the four wires are used to supply power to the sensors, and two more form a signal loop. To connect the network, a SHVVP wire or similar is used. Installation of sensors and laying of the cable channel is carried out using dowels and self-tapping screws.

PKP - the heart of the burglar alarm

The basis of the burglar alarm 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 a well-developed functionality and is perfect for a small apartment alarm.

Common devices with one loop:

Quartz
Astra 712/1
VERS-PK 1

The cost of devices does not exceed 1900 rubles. Each device has a place to install a battery in the case. Arming and disarming is carried out with the help of electronic keys "Touch Memory", which are included in the delivery.

Video how to make an alarm from the phone:

Self-installation of a security alarm

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 in sensor placement and will help determine the exact number of elements required.

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

Perforator
A hammer
pliers
wire cutters
Screwdriver Set
Tester

Choose a place

First you need to choose a place to install the main unit (PKN). It is usually installed on the wall of the hallway, next to the front door. It is desirable that an electrical panel or junction box be located nearby. In standby mode, the device must be constantly, so the power switch is usually not set. 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 advisable to use glass break sensors. All sensors are included in one loop.

The performance of magnetic contact sensors, before being connected to the line, is easy to check with a tester. When the door is closed, the circuit is closed, and opening it by 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 according to the size and configuration of the room. Such sensors are equipped with a swivel bracket, which makes it easier to choose the optimal angle horizontally and vertically.

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

We mount

Installation of a security alarm is carried out with a four-wire KSPV wire, as this allows the design of an apartment or house. It can be laid in a cable duct, run under the baseboard and door jambs. After completing the installation and checking the functionality, you can choose a place to install the signaling device. A triggered siren will force the offender to abandon their intentions, as well as inform the neighbors that something has happened in the apartment or house. The security alarm is controlled by electronic keys, the reader of which is installed next to the device.

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

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

Burglar alarm simulators

Do-it-yourself home security alarm system does not have to include expensive control devices and sensors. One of the most or at home would be to install a standard motion sensor that is used to turn on the lights.

The cost of sensors starts from 300 rubles.

Sensors of this type have a large detection area and can switch loads up to 2.0 kW, which allows turning on a powerful siren and lighting in case of violation of the protected area. 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 are operable over a wide temperature range.

In the market of security systems, you can already buy ready-made imitators (models) burglar alarms, which can be self-powered. The simplest ones are a regular red LED that operates in a pulsed 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.

If you are the owner of an expensive car, then most of all this article is not for you. And if you have a rather modest car and you want to protect your car at minimal cost (which is not at all proportional to the quality), then this description is for you.
The fact is that car alarm should not cost more than 5% of its market value, which for a used car is the amount for which you cannot buy a ready-made, more or less reliable, alarm system. The danger for a car without an alarm is not only in its theft, but also in the very penetration into the salon, theft of property, documents, etc., which is very common in the current conditions.
The damage may be small, or it may exceed the value of the car itself. In the traffic police, such cases are often not considered at all, since there is little evidence for them and they don’t initiate a case at all, stating that you yourself forgot your purse or documents somewhere, but you didn’t have any money at all. My friends had several similar cases, although the cars were equipped with purchased alarms.
But the fact is that scammers and thieves have long learned to bypass not expensive (although this is for someone), and rather monetary standard alarms. And it has become much easier to open (steal or rob) a car equipped with such a standard purchased alarm system. Now there are many different scanners with which an attacker reads your alarm code when you arm your car by giving a command over the radio from the key fob.

That's it, the "bad person" already has your code and he can easily both open the car and close it without attracting attention at all. Further, I think everything is clear to everyone. Therefore, having such an alarm, you significantly increase the potential theft or theft from the car, even compared to if you just locked it with a key, without the possibility of remotely opening the doors. And if we also take into account the human factor, the master who installs the alarm for you can naturally know how to turn it off, make a duplicate, etc.
Of course, most masters are decent people, but the facts show that if there is an opportunity, then someone will always take advantage of it. Data can be transferred to interested parties and "shoot" in a year or two after the installation of the alarm. It will be almost impossible to tie this into one whole, and even more so to prove it.
There are many more arguments not in favor of standard low and middle-class purchased car alarms, not to mention the costly part.

Consider the functions that a simple, inexpensive do-it-yourself car alarm should perform:

The alarm should respond to penetration into the car, for example, using an IR motion sensor, or from standard light buttons that work when a door or trunk is opened (the cheapest option, easy to implement, but nevertheless quite functional).
An intrusion alarm should notify with a sound, a regular signal or an additional siren. This notification should last a certain time, for example two to five minutes, and then automatically turn off.
After the alarm is triggered, the system should switch to the unauthorized entry mode - it should work repeatedly, block the engine start, etc.
- The car alarm must consume low current, excluding the discharge of the battery (regular or additional) during the long-term parking of the car on guard.
The mechanism of inclusion, transfer to the mode of protection and deactivation of the alarm system. In a simple case, a small delay (5-10s), after turning on the hidden toggle switch, while leaving the car and closing the door.
Easy to manufacture and connect with low financial costs with maximum efficiency.

Such an alarm system will reliably protect even such a work as the Six-wheeled "Cossack Hammer"

Below is one of the most simple car alarm schemes that you can make yourself.

The car alarm combines an acoustic alarm that is triggered by the short circuit of the sensors (buttons for turning on the light of the doors and trunk) and when the ignition is turned on and blocks the engine from starting.
This scheme is suitable for installation on domestic cars equipped with a classic contact ignition system (VAZ, Moskvich, Volga, etc.) and any foreign ones with a similar contact ignition system. (Previously, all cars had a contact ignition system - they turned the key - the contacts closed), Installation is also possible in many new cars.

Homemade car alarm scheme quite simple and understandable to any novice radio amateur. All details are public and cost a penny. The connection to the electrical circuit of the car is also shown in the diagram. The bold line highlights the signaling unit itself, which is assembled in a small plastic case, selected from those available or can be purchased on the radio market - to your taste.

Everything outside the bold rectangle is the electrical equipment of your car, as well as other additional elements that are introduced into the car circuit (Sensors K2 and KZ, two relays P1 and P2, toggle switch 51).

Two types of contact sensors are used - standard interior lighting switches located in the car doors (they are connected in parallel, so the diagram shows one K1 sensor and one H1 lighting lamp), and specially installed sensors (door type) under the hood and trunk lid, if the trunk not equipped with a regular switch, similar to a door switch - so that when closed, their buttons are pressed and the contacts are open. When opening, the contacts must close.

As a sound signal source of the car alarm system, the regular signal of your favorite car or an installed purchased siren can be used. The signal is switched on using an additional electromagnetic relay of sufficient power (since the current passes through the signal coil), which must be installed in the engine compartment of the car - P1. The same P2 relay is used to block the ignition system. In principle, this relay can be placed in the box of the alarm itself. Its winding is connected in parallel with the P1 winding, and when the alarm relay P2 is triggered, it shunts the capacitor C of the ignition system with its contacts, which makes it impossible to spark and start the engine.

The car alarm is turned on with the help of a micro-toggle switch 51, which must be installed in a "secret place" inside the car (usually somewhere under the panel), known only to you and authorized persons. After turning on the power, the device will not respond to the status of all sensors for 15-20 seconds. This time is allotted for getting out of the car and closing the doors. After this time, the car alarm goes into armed mode.

To increase reliability, you can use an independent additional small battery, this is at will, desire and financial capabilities.

Even without an independent power source, such an alarm in modern conditions will be more reliable than a simple purchase with a remote control. About the cost is clear and so.

The system is economical. In standby mode, it consumes less than 0.7 mA, the trigger mode is 1.1 mA, and the current of the signal or siren is 0.2-0.5 A

Additionally, you can add an infrared motion sensor - purchased or if one was lying around on the farm.

If the sensor for 220V must be converted to 12V (8-20 Volts). A standard household motion sensor must be opened. The spherical part is removed by bending one support. The halves are fastened with latches.
Pull out the fee. The sensor is a passive IR receiver that responds to changes in the IR radiation that hits it. Typically, the motion sensor's field of view is 180 degrees.

Another simple car alarm circuit without chips

The circuit works on a similar principle, using the same sensors as in the previous case.

Short description:

SA2-SAn - intrusion sensors (door buttons, etc.). Diodes VD5-VDn are used to isolate the sensors if they are used for other purposes. If the sensors are only for signaling, diodes can be excluded.

The supply voltage supplied from any closed sensor, through R1 C1 is supplied to VD1. The R1 C1 circuit creates a short current pulse even if the sensor is left closed. Capacitor C2 prevents the alarm from triggering when the SA1 toggle switch is turned off.

The output key and multivibrator are assembled on the elements C4, R4, R5, VT2, K1. The duration of K1 being in the on position is determined by the selection of resistor R5 (you can install a variable resistor), and in the off position - R4. The overall pulse frequency is set by C4. This part of the circuit requires more careful tuning. Approximately around 2 Hz.

On elements C3, VD3, VD4, a node is assembled, which forms a delay in the alarm operation when the intrusion sensor is closed. This is necessary to delay the operation of the siren when the owner opens the car for 4-8 seconds to turn off the device (so as not to scare others :-)). The duration of the delay is set by the capacitor C3. The discharge of the capacitor when the power is turned off is provided by the resistor R3.

In this scheme, there is no node that would turn off the alarm after a while, this is the simplest option. If desired, such a node can be modified by slightly complicating the design, or you can use an autonomous time relay with periodic reset.

VD1 - any low-power thyristor, for example KU101. You just need to select C1 (increase if the alarm does not work when the sensor is closed), R2 (decrease if it does not work) and C2 (increase if it works immediately when the circuit is turned on). Diodes - any low-power. Relay K1 - RES55A, or similar (selected according to the power of the switched current of the siren-signal). If you use a more powerful relay (more than 1A), then you will need to increase the capacitances of capacitors C3 and C4 quite a lot (this will lead to an increase in the size of the device). Therefore, if you have a fairly powerful load, it is better to connect a powerful relay to the RES55A output. Transistors - also any, with the appropriate transition structure, and VT2 must withstand the relay turn-on current. SA1 - any small switch (tumbler).

To turn on the car alarm:
1. Turn on the SA1 toggle switch with the sensor closed (with the door open). In this position, the circuit will not turn on and can be indefinitely.
2. Close the door - the circuit switches to armed mode.

To turn off the car alarm:
1. Open the door (this will close the intrusion sensor).
2. Fast, within 8-10 sec. disarm - turn off the SA1 toggle switch.

DIY simple alarm

Good day, friends! Now I will show you how to make an easy, but at the same time reliable alarm in just 5 minutes. This alarm is perfect for camping, field conditions, for giving, or garage.

This is an excellent replacement for all sorts of things when you need to install an alarm, but there are no serious security devices at hand.

You have probably seen action films where the main character put up streamers to ensure the security of the perimeter. In this video, I'll show you how to do a similar stretch in a few minutes. Only this stretch-alarm will not explode and scatter body parts of bad guys :).

This will warn about the penetration of strangers into the territory of your campground, yard in the country and will protect you, not only from people but also from dangerous wild animals.