With the alarm systems of the latest generation, the weak points of a house can be optimally secured. Major installation work is not always necessary.
In contrast to the small individual detectors, which we presented in the last DIY, alarm systems form a coherent system. They consist of three components. The messengers, which act as sensors for physical changes such as vibrations, Record noise or temperature fluctuations and forward them to the control panel. This transmission can take place via wire or via a radio link. The incoming impulses are processed in the control center, the alarm is triggered and forwarded to the donors. The alarm can be visual by light or flashes, acoustically by sirens. other noise instruments or via electronic components, which in turn switch devices or trigger other functions.
The encoders are triggered by interrupting a magnetic field (Type- and window contacts), by the frequencies generated when breaking glass, through pressure or tension contacts, by the slightest vibration or by interrupting an infrared beam. Motion detectors react to moving infrared radiation emanating from the human body or objects. Contact plates under floor mats react to pressure, on movement furniture- or simple switching contacts.
radio equipment
Because all doors and windows with magnet- or vibrating contacts or. Glass breakage sensors must be equipped, there is no way around a complex cable routing through the whole house. The cables are thin and easy to lay, but the effort is not insignificant. A line leads to each detector, which also contains a sabotage line. She sets off the alarm, if the system is manipulated.
It is easier to install a system with radio transmission. The free-standing motion detectors with built-in batteries forward the alarm wirelessly to the control panel. Contact detectors also work independently of the mains and via radio, where several glass breakage sensors or magnetic contacts connected via plugs can be connected. Installation work is thus reduced to a minimum.
It is also possible to combine both systems: via wire in easily accessible places, by radio for distant objects. In small systems, the signaling siren is included in the control panel. External sirens and flashing lights can be connected.
Complete systems and centers
The heart of every alarm system is the control panel. In it, the incoming impulses of the different alarm lines from detectors and sensors by wire or radio are processed (circuits) recorded, processed and corresponding alarms activated.
The alarm can be immediate or delayed. The delay gives house residents the opportunity, switch off the system via a secure system after entering. It can also be deactivated using a small hand-held transmitter. A system is activated either manually (also with a delay) via security or combination locks or. from the outside via radio. An emergency power supply is important for all alarm systems, which should be built into the control panel. It supplies the system with constantly charged batteries
or by batteries with energy, if the power fails or has been switched off by manipulation. Alarm centers are available as compact devices or you can put them together yourself from individual components. Depending on the type and size of the object to be secured and the local conditions, individual planning can be carried out. Brochures and prospectuses from manufacturers and distributors of alarm systems should be consulted when planning the entire system. The advice centers of the criminal police also provide information and advise self-builders of alarm systems.
However, most insurance companies only take investments into account with a favorable effect on premiums, if they have been installed by an approved specialist company.
alarm
The individual circuits of an alarm system are referred to as alarm lines. They function according to the working current- or the quiescent current principle. Most encoders can be used for both operating modes. working current means, that after the activation of the detector, the circuit is closed. quiescent current means, that all contacts are closed when idle and open when activated. A combination of both systems in one line is also possible. Each line is activated by a switch, which works in reverse to the connected detectors. Protection against sabotage is possible by installing special resistors, reports the manipulation immediately.
Reporting
Sirens and strong flashing lights are the typical alarms for inside and outside. There are weatherproof combined devices for the house facade, for inside smaller, but no less bright or. loud models. Transmitters can also be relays, the stronger power consumers such. B. Use headlights, or telephone caller, who start a call to a memory number.
Install special detectors
Less with burglary, but detectors have a lot to do with home security, which should be connected to the alarm system. You can use a special line to trigger an alarm in the event of flooding, with an overflowing washing machine in the basement, when smoke occurs or as a flame monitor if the heat is too high.