Sometimes it becomes necessary to install a simple and not expensive security alarm. Without the extra bells and whistles that manufacturers add to it to expand the functionality of their system and somehow distinguish it from other competitors. A summer house, a garage, an extension or even a greenhouse, in such places it is not always advisable and advantageous to install a complete security system.
In this article, we will consider several devices that claim to be simple and accessible to anyone who wants to protect their property from the encroachment of unsolicited guests.
What should such an alarm be able to do?
respond to an invasion (some kind of external impact – movement, the door is opened, hit, etc.);
give a sound signal to frighten offender;
be able to arm and disarm;
it is desirable to consume a little electricity.
These devices are aimed not so much to block access to the house, but only to scare away the thief. Hearing a loud signal, he will not want to take risks and will not climb into the room, in addition to psychological impact, it can still attract the attention of neighbors.
Security alarm based on motion sensor
The simplest burglar alarm for the home can be made on the basis of a conventional household motion sensor for lighting, which are installed in the entrances, to save electricity. But instead of a lighting lamp, you can install a siren.
What is needed for this?
Motion sensor – you can buy in any hardware store, such as OBI or Leroy Merlin. It is necessary to pay attention to the voltage of the sensor – we need it to work from a 220V network, the viewing angle depends on the external version of the sensor (wall or ceiling) and the lens used (it can be 180 degrees wide or a corridor type). The average cost is from 400 to 800 rubles;
The siren working from a network 220V. For example, PKI-3 “Oriole-220”, the average price is 250 rubles. You can buy in radio stores;
Normal switch to turn off the alarm. Anyone from 100 rubles will do. and higher.
The connection diagram is presented below:
motion sensor and siren
The motion sensor must be chosen such that it has at least two types of adjustments – the time setting (TIME) and the sensor sensitivity (SENS). With the help of the first, it will be possible to set the time for the alarm to trigger, i.e. siren time. This value is usually set for five minutes. The second adjustment changes the sensitivity of the sensor, for example, if it does not respond to you or to reduce the so-called “false alarms”.A switch will be needed in order to turn off the device when you are in its field of view and turn it on when you leave this room. It is advisable to install the switch secretly, so that after activating the security alarm you would not fall into the radius of its operation. In addition to the siren, you can also connect a conventional light bulb for double exposure to the intruder. DD-03
The main disadvantages of this implementation will be that some models of motion sensors after switching on take from 1 to 10 seconds to “stabilize” and switch the operation to standby mode. If you come across such a sensor, you need to add a time relay to the general circuit, which will keep the siren disconnected for the time it is turned on.
On sale there are still miniature motion sensors that operate on 12V, for example, the DD-03 model. They can also create a simple alarm, but you need to connect it to a 12 volt power source or battery. Thanks to this, the system will be non-volatile and work, even if there are interruptions in electricity.
Security alarm from the ready-made kit
The simplest security device based on an autonomous alarm can work without wires. In amateur radio stores, you can find two options – based on an infrared sensor (aka movement) or a magnetocontact sensor that responds to opening. True, the choice is not large enough and you will often have to go shopping to find the goods “in stock”. Therefore, the easiest way to purchase this product is to order it in one of the largest online stores.
Kit based on infrared sensor.
An example is the Chinese alarm system under the loud name “Alarm mini”. It consists of the IR sensor itself, an arm for installation and one or two key fobs. The kit contains clear instructions for installation and operation. 4 AA batteries are bought separately, but can also be powered by a 6V power adapter (sold separately). It is not difficult to complete the installation yourself.
After inserting the batteries into the device, you need to install the unit itself in such a place so that its lens is directed to the protected room. On the front panel there is an infrared receiver window to control the alarm from the remote control. A lens that “captures movement” in a controlled area, operation indicators and a siren.
We press the button on the remote control – the green LED lights up, which means that the exit report has gone (15-20 seconds) in order to leave the apartment. Then the green eye goes out – the device began to work.Now, as soon as there is any movement in the room, a person will pass, a dog or a cat will run, a red LED will light up and after 15-20 seconds a very loud siren will sound. The device is working!
Kit based on magnetic sensor.
yl-333 An alarm based on the opening sensor is the main unit in which there is a sensor with open contacts and a magnet for closing these contacts. It is necessary to establish them against each other so that there is direct contact between them. If a thief has entered the house, when you open the door or window, these elements are removed from each other and an alarm siren sounds.
Such an alarm can be used mainly to deter intruders and its main advantage is the low price, about 100 rubles per sensor. And it’s very simple installation, on each part there is adhesive tape, it is enough to remove the protective layer and stick the sensor on the front door or window.
Often, such kits are used to protect the perimeter of the house at a time when you are inside, for example, sleep at night. The sound of a siren will also wake you up and you can take any action to protect yourself.
Burglar alarm simulator
In urban multi-storey buildings, it becomes popular to arm an apartment; in this case, expensive equipment to protect against penetration is bought, and signals are transmitted to the control panel of the security company. But not every owner can afford it, and it is not always justified.
Remember in cars such a device, under the windshield, usually near the steering wheel, is a red LED that is blinking or constantly on? He warns that the car is under guard. So for an apartment or a summer house there are similar designs or in another way – security alarm simulators. They are designed to frighten off unprepared and unprofessional thieves or housekeepers.
security alarm simulator To make such a simulator, you need to buy a red LED (for example, such an AL307), a mounting box for its placement, a 100 Ohm resistor, a switch and a compartment for two batteries. For the whole set you will need to pay approximately 100 – 200 rubles. Depending on the characteristics of the LED, a current-limiting resistor must be connected to it in series. They will help you choose the right resistor in the radio goods store (if you, of course, do not have the Soviet AL307 LED, as in our example).
Leaving the house, turn on the constantly glowing LED, returning, turn it off. Aliens will think that the apartment is on the alarm.
fake-security-alarm If there is no possibility or time to assemble such a simulator yourself, then you can install a fake security alarm. This ready-made device combines a light and sound siren, can operate from a 220V network and be autonomous, i.e. powered by batteries. When the apartment or cottage is supposedly on guard, the indicator light is red or blue.If a thief tries to open the door, an audible howler will sound – a siren.
Thus, we can assume that a small box and a burning LED or light bulb are signaling indicators that will make it clear to the intruder that you should not meddle here.
Quite often you can see that in shops, in offices, on street kiosks, stickers of various security companies are pasted. You can also take advantage of this by sticking such a sticker over your door. No one will check whether the apartment is really connected to the remote security department.