Mechanical, electronic and wireless calls

During the mass introduction of innovative technologies, scientists are trying to improve all kinds of objects around us. The fate of inventors has not been bypassed and such a miracle-invention as a bell. The device for notifying the owner about the arrival of guests appeared long ago, gradually improved and in the 21st century reached an almost ideal state. At this time, there were wireless calls.

Mechanical calls

A knock at the door is, perhaps, the first "bell" invented by a man. It was not invented specifically, rather, it originated on a subconscious level. Approaching the dwelling, the man wished to warn the owner of his arrival. It was enough to knock on the wall next to the entrance. Later, when the entrance doors became thicker, and the dwelling - more spacious, the knock became insufficient to alert the owner. He could not physically hear the "call". Then the inventors came up with how to amplify the sound of the signal with a special device attached to the outside of the entrance door. It was a bell or a ring. When a mechanical impact on him appeared a sound, it informed the owner about the arrival of guests. Until now, in many ancient castles and mansions one can see such devices, they have become not only a necessary means of warning, but also a luxury item.

Electric bells

After the invention of electricity, scientists tried to attach any object in the house to it. This also affected the doorbell. The electrical analog consisted of an external button, a sound reproducing base, and wires connecting the two main parts. In this case, a separate wire led to the device electricity. Currently, such calls exist in every home. This is the easiest way to notify the owner about the arrival of guests. Sometimes electric bells are equipped with independent power supply with the help of batteries. On the one hand, it is convenient (turned off the electricity, and the bell works), on the other - not very (batteries are not eternal and are subject to frequent replacement).

Wireless Calls

People are constantly striving to introduce new technologies into everyday life. So, in place of the usual electric came wireless calls. This achievement of the last decades is very popular with the inhabitant and has taken root in our homes. For example, a wireless call for a summer residence or a private house made it possible to get rid of the need to pull wires from the gate to the entrance door. The principle of operation of such a device is based on the use of radio waves of a certain frequency. With them, the signal from the push-button at the input is transmitted to the modular unit in the room. Wireless calls, as a rule, work from rechargeable batteries. This is quite practical, but requires constant control over the level of charge. Another disadvantage of using such a call is a small radius of action - approximately 100 meters. And this is provided that in the way of transmission of radio waves there are no serious obstacles such as steel doors or concrete walls.

The inventors constantly improve such devices and equip them with additional functions. For example, a wireless call "Cosmos" can play melodies in MP3 format. If it is necessary to equip several objects with one device, for example, if there is one gate in a townhouse or on one door of an apartment building, additional bases with screens can be purchased to the usual set. Some wireless calls allow the host to communicate with the guest through two-way communication. If there are several entrances / exits in the house or in the cottage, it is worthwhile to place calls to each gate separately, while information about the call of the owner will come to one base, it is only necessary to buy a few more buttons. Here, convenience is that when you purchase the first set, you do not need to guess in advance the number of necessary additions. The main condition remains one manufacturer of products. It should be noted that with temperature changes such a call may simply not work, the temperature maximum and minimum is usually indicated in the instructions for the wireless call.

On the shelves of stores are presented models of such devices for a special circle of users, for example, for people who hear badly, the base is additionally equipped with a light bulb that lights up when a call comes in. Basics can be both stationary and portable. A small module with an LCD screen, no bigger than a tablet, can be placed on a coffee table and couch or taken to the second floor.

Wake-up call

This is the last achievement. It is mounted for 10 minutes instead of the usual door eye. With its help you can not only call the door, it gives the owner the opportunity to easily look at the monitor who came. Such models are equipped with different functions: photo or video recording, lighting, setting the date and time, motion sensor. This is very convenient, especially in the absence of household members. After the arrival of the owner can easily see the record and see who came and when. The motion sensor helps to maximize battery life. The device is in the "sleep" mode and starts recording if within a radius of 1-1.5 meters recognizes the movement. Ultra-violet illumination of the bell-eye helps to monitor the inter-apartment space even during a power outage.