Schemes of three homemade alarm options (CD4093). A simple stand-alone burglar alarm with your own hands Burglar alarm loops and sensor connection

A distinctive feature of this circuit is that it is built on the simplest element base - a microcircuit with six K561LH2 inverters and an operational amplifier in the sensor system. With all this, the signaling provides the entire set of functions for devices made on a larger number of microcircuits. The car alarm circuit allows two versions, with a delay in turning on the sound signal to turn off the alarm from the passenger compartment, and a variant with instantaneous activation of the signal after the sensor is triggered, and external activation of the delay by the owner using a reed switch and a magnet key fob.

The car alarm consists of three nodes:

A system of two sensors - a body vibration sensor made on the basis of a microammeter connected between the inputs of a voltage comparator, and a contact sensor, the role of which is played by the car door switch.
- a logic circuit on RC circuits, consisting of a pulse shaper, a single vibrator, a multivibrator,
- an actuating device, which is based on an electronic key on a composite transistor and a regular car horn relay.

The algorithm of work is as follows. The security device is assembled in a small plastic box, which is connected to the car's systems using a cable with a standard five-pin connector from the audio equipment.

Before leaving the passenger compartment, the owner connects the security unit using a cable to the socket installed under the dashboard of the car and puts the body of the device on the dashboard (in the version with a reed key) or turns on the power using a secret switch (in the version with a delayed start, while the body instrument is installed in the dashboard of the car).

After turning on the power, the alarm does not work for 30-40 seconds. This time is needed for the owner to leave the passenger compartment, close the doors, etc.

After this time has elapsed, the watchman switches to the driving mode. When a signal is received from one of the sensors (body vibrations from attempts to break the door, hood, trunk, removing the wheel, closing contacts when opening the door), the watchman in the version with a delay works out a delay of 5 seconds to turn it off by the owner, in the version with a reed switch, without delay, and then turns on an audible beep that lasts about 20 seconds. The circuit then returns to its original standby mode.

To disable the reed switch alarm, the car owner must first bring the magnet key fob to the reed switch located, for example, behind the windshield for upholstery, and then open the door and turn off the alarm by disconnecting the cable from the connector.

The circuit diagram is shown in Figure 1. When the circuit is connected to a power source, capacitor C4 begins to charge through resistor R4, as a result, a logical zero enters input D1.5 through diode VD4, which fixes the multivibrator at D1.5 D1.6 in the position of logical zero at the output . After charging C4, VD4 ceases to affect the operation of the multivibrator. The device enters the search mode.

When the car body oscillates, the magnetic system of the inertial sensor based on a microammeter generates a variable EMF that occurs between the D2 inputs and is amplified by this comparator, converted into negative pulses. One pulse is enough to trigger.

When the door is opened, the contacts of the door switch are additionally closed and the first contact of the XS1 connector is connected to ground, as a result, through VD1 a negative level or through VD2, a negative pulse is supplied to the shaper on two elements D1.1 and D1.2. Negative
a pulse from the output D1.2 through the diode VD3 discharges the capacitor C2 of the single vibrator on the elements D1.3 D1.4.

At the same time, a high level appears at its output, which, after the sensor stops working (the door is closed, the car stops rocking), turns into a positive pulse lasting about 20 seconds (if the door is open or the car continues to rock, the pulse is proportionally longer).

Fig.2
This pulse, in the delayed circuit, enters through the RC circuit R3C3 to the cathode of the VD6 diode and the multivibrator D1.5 D1.6 leaves the fixed position and starts to generate positive pulses that are fed to the transistor key on VT1 VT2, which controls the turntable of the audio signal (in fact, the key turns on parallel to the car horn button).

In the reed switch circuit (Figure 2), the resistor R3 and capacitor C3 are removed, and the cathode of the VD6 diode is connected directly to the output of the single vibrator, it is clear that the multivibrator D1.5 D1.6 turns on immediately after the sensor is triggered. The reed switch is connected in parallel with the capacitor C4, which creates a time delay after the power is turned on.

It turns out that when a magnet is brought to it, its contacts close C4 and discharge it, a logical zero enters the VD4 cathode, as during the exposure after switching on. It turns out that the alarm has just been turned on and there are 30-40 seconds to close the doors and exit, which can be used to open the doors and disconnect the HS1 connector.

Fig.3
The entire device is mounted on a single printed circuit board, the wiring diagram of which is shown in Figure 3 in full size (corresponding to the natural size of the board).

The board is placed in a plastic case on the cover of which the LED is attached.

The inertial sensor is made from an M470 type indicator from a cassette recorder. It is necessary to separate the halves of the case and remove the cover that covers the scale, then fasten a flat weight, such as a washer, on the arrow so that it does not touch the scale and glue the case back.

Of course, you can buy a security unit in the store. There are various devices on the market. But what if you don't want to overpay for different options. In addition, your hands grow from where you need. No problems!

You can assemble a completely acceptable option yourself. This car alarm has nothing superfluous: central lock control, remote control. But homemade will protect your car from penetration with the help of door and trunk limit switches. And also with the help of a shock-vibration sensor it will warn the owner about unscrewing, for example, wheels. By the way, did you know that it is much more difficult for an attacker to disable this kind of alarm. He doesn't know what you could put in there. In addition, in the absence of a key fob, the degree of protection increases many times over, since auto-crooks will not be able to read the code (after all, it is known that most hacks occur by this method).

Device diagram

Principle of operation is as follows. The signal from A1 of the vibration sensor goes to the amplifier, which is made on VT1, VT2 and controls the thyristor VS1. The base of the transistor VT2 also receives a signal from the limit switches of the doors, hood, trunk. A timer is assembled on transistors VT3, VT4, which controls the anode of the thyristor VS1. The VT3 base circuit uses a large capacitor C3. Due to this, when armed with a securely hidden toggle switch, C3 starts charging through the car's siren and a circuit of resistors R6, R7. In the process of charging the capacitor, VT3, VT4 will be closed, therefore, the thyristor VS1 is locked. Due to this, the circuit is armed with some delay, giving the driver time to leave the car and close the door.

After 20 seconds, the capacitor C3 gains capacity, VT3 opens and turns on the protection. Suppose there was an impact on the car or the opening of a door. Thyristor VS1 unlocks, starts charging C4 through VS1, VT4, R10. The thyristor is designed in such a way that it remains open during the passage of direct current. When the door is closed (signals stop), the alarm siren will notify the owner of the intrusion. If the sensors were triggered with the appearance of the owner, then during the charge of C4 (20 seconds), he will turn off the disguised toggle switch. If this is not done, then VT5, VT6 will open, relay KV1 will turn on, which in turn will connect the siren. In order not to disturb the neighbors and not to run to the car during false alarms, such as a truck passing by, this car alarm has an alarm time limit function. It operates in the following way. When contacts KV1 are closed and current flows through R6, R7, capacitor C3 is charged. After a short time, VT2, VT3, VS1, VT5, VT6 will close and the KV1 relay will turn off and arm again.

What details can be used to implement the schema. Requirements for them are not critical. Capacitors and resistors of any type, preferably small. Relay KV1 with an operating voltage of 12 volts and a coil current within 100 mA. The power contacts of the relay must withstand a current of 5 A. But it can be reduced to 0.5 A if an intermediate relay is used.

The vibration sensor A1 is not difficult to make yourself. It is made in the form of a coil with a steel core, from which a permanent magnet is fixed at a short distance on a flat spring. At the slightest impact on the car body, vibrations are transmitted through the spring to the magnet. That, in turn, will create an alternating magnetic field, which will induce an EMF in the coil. The latter, Ø10x15 mm in size, is wound on a steel core Ø3 mm. For winding, copper wire 0.06 ... 0.07 mm is used. A magnet with dimensions of 25x10x5 mm must be fixed to the spring with glue and thread. As which you can use the spring from the alarm clock. The length of the latter is selected within 60 - 80 mm. When assembling the shock sensor, care should be taken to ensure that the magnet can be positioned as close as possible to the side of the coil. The finished vibration sensor should be placed in space so that the magnet can oscillate perpendicular to the ground.

Homemade vibration sensor

Now the most important thing remains - to hide the toggle switch through which power is supplied to the circuit. This issue should be approached with no less responsibility. Since you have to use it all the time, well, the attacker should not detect it.

Three homemade security devices with an alarm, each made according to the scheme using the CD4093 chip, simple do-it-yourself homemade products. The CD4093 chip is very similar to the K561LA7 or CD4011, it has exactly four “2I-NOT” logic elements, and matches the pinout.

But it differs in that these logical elements are not ordinary, but with the Schmitt trigger effect. That is, there is a significant hysteresis between the threshold of zero and the threshold of one. This gives the chip a lot of additional interesting properties, and the circuits built on it work more stably. In this sense, the most interesting application of CD4093 in simple security devices.

Security device with photo sensor

Figure 1 shows a diagram of a signaling device that can be installed on a passage or path. It is triggered by the intersection of a beam of light emitted by a super-bright indicator-type LED. When the beam is crossed, it turns on an audible alarm that sounds for about 15 seconds.

The audible alarm is a sound with a frequency of about 2000 Hz, intermittent at a frequency of about 2 Hz. Turning on and off with a switch that works in reverse (closed - off, open - on). After switching on for about 15 seconds, the circuit does not respond to the sensor.

HL1 is a super bright indicator LED. The current is supplied to it through the resistor R1 from a common power source. The current is constant. The second part of the sensor is a phototransistor 2N5777. In working condition, the LED and the phototransistor are strictly aimed at each other.

It is desirable that the phototransistor be covered with a hood in the form of a tube. This will reduce the chance of direct sunlight hitting it, which could interfere with the alarm.

Rice. 1. Signaling scheme that reacts to the intersection of a beam of light.

As long as no one beam crosses the phototransistor FT1 under its action is open. And pin 2 D1.1 receives a logic unit voltage through it. The output of D1.2 is also one. Diode VD1 is open and blocks the multivibrator on element D1.3. Zero from its output blocks the multivibrator on D1.4.

Its output is one, so the key on the multi-structure transistors VT1 and VT2 is closed, the current does not flow through the speaker BF1.

When crossing the beam, the phototransistor closes, and the voltage at pin 2 D1.1 drops to logic zero. This causes the start of a single vibrator on the elements D1.1 and D1.2, which forms a zero drop at the output of D1.2 with a duration of about 15 seconds. At the same time, VD1 closes and starts the multivibrator at D1.3, which generates pulses with a frequency of about 2 Hz.

Switch S1 is used to turn it on and off. In order to turn off the alarm, you need to turn it on. In this case, the capacitor C2 is discharged through it, and remains in this state. A logical zero is held at pin 6 of D1.2, so its output will always be a logical one, regardless of the state of the sensor. After turning on the alarm by turning off S1, the circuit will not respond to the sensor for another 15 seconds while C2 is charged through R4 to a logic one voltage.

Alarm with code switch

Figure 2 shows an alarm diagram for an apartment, office, warehouse or other premises. The scheme is similar to the previous one, and differs mainly in the sensor, which is used as a standard reed door position sensor (SG1). There is a difference in the scheme of switching on and off.

Rice. 2. Scheme of a home-made alarm system with a code shutdown.

Switching on is done by switch S10, which supplies power to the circuit. After switching on, the circuit is not receptive to the sensor while charging the capacitor C2 through the resistor R4 (15 seconds). When the door is closed, the contacts SG1 are closed and through them the voltage of a logical unit is supplied to pin 2 D1.1. In this state, the VD1 diode is open and the multivibrators on D1.3 and D1.4 are blocked. No sound.

When the door is opened, the SG1 contacts open, and at pin 2 D1.1 the voltage drops to logic zero. This causes the start of a single vibrator on the elements D1.1 and D1.2, which forms a zero drop at the output of D1.2 with a duration of about 15 seconds. At the same time, VD1 closes and starts the multivibrator at D1.3, which generates pulses with a frequency of about 2 Hz.

On the front of each of its pulses, a multivibrator on D1.4 is launched, generating pulses with a frequency of about 2 kHz. They are fed through a transistor switch to VT1 and VT2 to a high-frequency horn dynamic head BF1.

Shutdown is carried out in two stages. First, using a simple code keyboard on the buttons - switches S0-S9, the code is entered by simultaneously pressing the buttons of the code number (such a keyboard is repeatedly described on the pages of this publication, and therefore I see no need to tell how it works).

In this case, through a closed circuit S0-S9, the capacitor C2 is discharged. You now have 15 seconds to enter the premises and turn off the alarm with switch S10.

car alarm

Figure 3 shows a diagram of a simple car security device made on the same basis. Here, the sensor is the circuit for automatically switching on the interior lighting of the car. In any passenger car, sensors are installed in the doorways, which close when the door is opened and turn on the interior lighting lamp. This circuit is also very often used as a door open sensor for signaling.

When the door is opened, the circuit is closed to a common minus. There is no longer a tweeter at the output of the circuit, because a car horn is used as an audible signal. The collectors of transistors VT1 and VT2 are connected to the horn relay, which is available in the car circuit.

Rice. 3. Schematic diagram of a homemade alarm system for cars.

Switching on is done by switch S1, which supplies power to the circuit. After switching on, the circuit is not receptive to the sensor while charging the capacitor C2 through the resistor R4 (15 seconds). When the doors are closed, the contacts of the door sensors are open and a logic unit voltage is supplied to pin 2 D1.1 through resistor R2.

In this state, the diode VD1 is open and the multivibrator on D1.3 is blocked. No sound.

When any door is opened, the door sensor contacts close, and at pin 2 D1.1, the voltage drops to logic zero. This causes the start of a single vibrator on the elements D1.1 and D1.2, which forms a zero drop at the output of D1.2 with a duration of about 15 seconds. At the same time, VD1 closes and starts the multivibrator at D1.3, which generates pulses with a frequency of about 2 Hz.

On the front of each of its pulses, a transistor key opens on VT1 and VT2, and the car's horn relay turns on its horn. Sounds are heard repeating at a frequency of 2 Hz.

Shutdown is carried out in two stages. First you need to bring the permanent magnet to the reed switch SG1. In this case, through a closed circuit S0-S9, the capacitor C2 is discharged. You now have 15 seconds to enter the premises and turn off the alarm with switch S1. The SG1 reed switch must be placed somewhere behind the glazing of the car body. A magnet can be made in the form of a keychain.

Details

In the diagrams in Fig. 1 and 2 as a BF1 speaker, you can use any high-frequency dynamic head with a resistance of at least 4 ohms, preferably a horn. The CD4093 microcircuit can be replaced by a domestic analogue - K561TL1 or any other analogue of the "4093" type.

LED HL1 - any indicator super bright LED. The greater its brightness, the wider the distance can be between it and the phototransistor. The 2N5777 phototransistor can be replaced with any other phototransistor or even a photoresistor. In this case, it may be necessary to select the resistance of the resistor R2. Diodes 1N4148 can be replaced with KD522, KD521 or other analogues.

BC557 transistors can be replaced with KT3107, BC547 transistor - with KT3102, TIR61 transistors can be replaced with KT815 or KT817 transistors.

In the process of adjusting with resistor R4, you can set a delay after switching on. Resistor R3 can set the duration of the alarm. Resistor R5 can set the frequency of repetition of signal sounds. Resistor R6 - sound tone.

For clarity, all diagrams retain the general sequence of part numbering adopted in Figure 1, therefore, in Figures 2 and 3, some positions are omitted.

Gorchuk N. V. RK-2017-02.

Installing a GSM security alarm in a country house, garage or private house allows you to ensure the safety and security of property. Management is carried out by phone, and for installation with your own hands you need to master all the features of the system.

The principle of operation of the GSM-alarm system

GSM signaling is a set of devices that are interconnected by a GSM network and interact through a signal. The elements of the complex are installed at the facility, and the control and reception of signals is carried out using a fixed or mobile phone, which is with the owner. So you can receive alarm notifications about the penetration of unauthorized people into the protected object. The system is controlled according to the same principle, but for this you need to send the necessary signal from the phone. As a result, it is possible to activate fire extinguishing systems, control electronic locks and other elements at the facility.

Scope of the security system

Security systems operating over the GSM network are diverse and widely used in private houses, garages, summer cottages. The use of alarms for cars is effective, but such a system differs significantly from the complex for real estate. Small remote warehouses, industrial premises or other structures can easily be equipped with such devices. Functional alarm allows you to respond in a timely manner to a fire or damage to property, to prevent other unpleasant actions of intruders.

Devices, depending on the model, perform the following functions:

• ensuring fire safety of a dacha, garage or other object;
• control of the presence of electricity in the network;
• control of leaks and overlapping of water valves;
• gas pipeline leakage control and shutdown of the system;
• activation of the siren, as well as heating or irrigation on the site;
• listening to the premises;
• room temperature control.

Various sensors can be included in the complex of devices, for example, for monitoring the integrity of window panes or smoke detectors. This allows you to vary the functionality of the security system. Therefore, the GSM complex is optimal not only for summer cottages, garages or private houses, but is also used for greenhouses, private facilities under construction and other structures.

Device components for home and garden

A simple version of the alarm system does not require the presence of complex devices, which allows you to create a security system yourself. In this case, it is necessary to understand the principle of operation of the entire complex. As a result, you can create an effective GSM alarm system for your summer house or garage with your own hands. It is so easy to avoid the cost of acquiring expensive equipment.

The following components are required for signaling:

• a simple push-button mobile phone in working order;
• finished sensor or reed switch + magnet;
• switch;
• mounting wire;
• soldering iron and solder;
• SIM card.

Do-it-yourself system assembly

The complex of the security system assumes the presence of a control unit with outputs for sensors and annunciators. The occurrence of emergencies triggers commands that are pre-programmed. For example, in case of violation of the integrity of the window panes in the house, the system is able to send an SMS message to the owner. Listening to everything that happens in the house is also possible when calling to the unit located in the guarded house.

First you need to determine what type of sensors are needed at the facility. Devices that detect damage to window glass, as well as those sensitive to smoke and rising air temperature, are in demand. Special motion sensors are also installed on the front door. After determining the types of devices, their location is selected.

The complex of works includes the following stages:

Video: alarm with motion sensor

A simple system with a minimum of detail is convenient, but a more effective signaling that responds to movements. The system is easy to create with your own hands, and video recommendations allow you to master the process.

Time relay system

GSM alarm schemes with a time relay are different, but simple options are easy to create with your own hands. In this case, the relay is necessary for the siren to sound, and the design may contain either two or one such element. In the first case, one relay activates the sound alert, and the other element turns it off after a set time period. The element has two groups of contacts. If there is one relay, the shutdown is carried out manually, that is, the alarm off button.

Video instruction for creating a time relay

GSM alarm system equipped with a time relay is functional and convenient. To master the rules and principle of operation of the relay allows the video, which presents the features of the installation.

Disadvantages of a homemade system

Simple assembly, economy, easy operation and the possibility of increasing functionality are the advantages of a home-made alarm for a summer house, garage or private house. The system is not without drawbacks, which are expressed in the following:

• easy blocking of the alarm by unauthorized persons;
• malfunctions occur quite often;
• a large set of functions requires the correct installation of each element;
• a complex system requires careful planning.

Expert reviews

The opinions of experts about the effectiveness of home-made devices are different. The location of the object is important, as well as the type of system. The presence of a siren often makes the alarm a method of scaring off intruders, but before creating a system, it is worth considering the reviews of specialists. Comments on the effectiveness of homemade devices are few, but contain some key points.

When installing an alarm in an apartment with pets, it is worth considering the reviews of experts:

Motion sensors can be adjusted to a specific response height. If your cat does not effortlessly jump to a height of 2 meters, and the intruder does not climb like a plastun (in this position, you can’t even open the closet!), Then the alarm is fully justified. The main thing is that the installation is carried out by specialists who understand the subject well.

Andrey Kotousov

Motion sensors can be configured to trigger only if an object larger than a certain size moves in the room. It can be configured so that when moving an object less than 10 kilograms there will be no triggers. My relatives have an alarm system in the apartment, including motion sensors. They have 2 cats that walk all over the apartment, while there were only 2 false positives, and both times when the cats knocked over massive objects (once their 4-story house) the 2nd carpet twisted in the corner. So the main thing is to set up correctly ...

Mikhail Karpov

https://answer.mail.ru/question/82855068

Project for homemade devices: yes or no?

There is no need to create a project when installing a home-made GSM alarm system. This is due to the fact that the system includes a minimum number of elements that are easily connected and interact with each other. At the same time, it is worth determining the location of the main unit, as well as the areas for placing all sensors. A schematic representation of the entire system allows you to quickly make an alarm with your own hands.

Laser signaling

A homemade laser alarm is an effective security system that is easy to operate. This uses more complex components than for GSM signaling. For example, a laser source, resistors and other elements are needed. The principle of operation of such a security system is that when the laser beam is interrupted, the voltage at one of the outputs drops below the reference voltage at the other output. At the same time, the degree of voltage increases at the output of the first operational amplifier, and the resulting pulse can be used to turn on the siren, searchlight and other devices.

Schema selection

The alarm, the action of which is based on a laser beam, is created according to the scheme. There are many options of varying complexity. The choice depends on skills in the field of electronics. For example, an effective system with a timer is quite simple and is actively used to protect private objects.

System creation

To install a laser alarm with your own hands, you need to prepare a BT169 thyristor, a laser, an LED light bulb, a capacitor, 47k resistors, a photoresistor or an LDR. Installation includes the following stages of work:

Advantages and disadvantages

Laser signaling is distinguished by such advantages as efficiency, long range, reliability and prompt response to emergencies. To create a system with your own hands, you need simple elements that are easy to purchase. The source of the laser beam is an ordinary pointer that gives a beam of red or another color. The finished device makes the assembly process simple.

The alarm has disadvantages such as the complexity of the assembly circuit, requiring knowledge and skills in the field of electronics. Additional elements in the form of a timer or other devices are important to properly mount and connect to the system.

Video: installation of a laser alarm

Detailed video instructions allow you to master all the features of self-assembly. At the same time, the alarm system will be economical, high-quality and efficient in use.

The GSM security system or a laser complex allows you to ensure the safety of property and the safety of the facility. For a summer house or a garage, it is easy to create a system with your own hands, but it is important to follow the installation rules and use high-quality components.

The idea of ​​this development does not belong to the author of this article, I just repeated and slightly improved the scheme. In general, we take one that reacts to opening doors (cost 40-50 rubles). In normal mode, it reacts to the opening of the door, but it is easy to convert it into a loop.

Such an alarm consists of an electronic unit with a siren and a magnet. In standby mode, the magnet closes the reed switch, when the magnet is removed, an audible signal sounds. In general, in many blocks there is not a reed switch, but simply a pair of open contacts ("chinacon", as the author of this device called this group of contacts). "Chinese" quickly either stick, or the contact surface is oxidized. So, I strongly recommend disassembling each block and installing normal reed switches. "Kitaikon", I can't show it, I threw it out a long time ago as it was not needed and put an ordinary normally open reed switch in its place. In order to equip this alarm with a loop, we drill holes for the clips for the loop from the ends of the block. M4x10 screws are used as clamps. The nut holds the screw in place, and a clamp is screwed over it, which presses the wire. If there is no special clamp, you can use a regular M4 nut, but it is naturally not so convenient to unscrew it without tools, you can also use a wing nut.

We connect the clamps to the terminals of the reed switch, that is, the cable is connected in parallel to the reed switch. As a loop, any thin copper wire that is easy to break is suitable. Such a wire can be found in any network transformer. Only usually it is covered with varnish insulation, which must be removed from the ends of the wire. So, the device is ready.

With a short piece of wire, such a burglar alarm unit can be used as a pocket siren. The alarm also works with a cable length of at least 5 meters. Also, the alarm does not lose its functionality if instead of a loop, a resistor with a resistance of 510 Ohms is connected, the same resistance has a piece of PEV 0.1 wire (diameter 0.1 mm) 230 m long. This loop is enough to surround a zone with a radius of 35 m around the perimeter. Which is quite enough to create a security perimeter around the tent. Thank you for your attention, you were Lekomtsev D.G.