To significantly improve the safety conditionselectrical systems and lighting circuits in many cases recommend the use of lamps with a voltage significantly lower than that used in the standard network (220 V). Usually such lighting is arranged in basements, bathrooms, cellars and other damp rooms. For these purposes, so-called halogen lamps with a working voltage of 12 V are used today. To supply power to lamps of this kind, a device such as an electronic transformer is used. This device is able to transform the mains voltage of 220 V into 12 V (optimal for the functioning of a halogen lamp).
If you look at the electronic transformer, thenyou can understand that the external device is quite simple. It is a small plastic or metal box, from which there is a conclusion of four wires: two incoming (with the inscription 220 V), and two outgoing (with the inscription 12 V).
The principle of operation of such a device aselectronic transformer, is simple enough. The brightness control is carried out with the help of thyristor regulators (they are called dimmers). These regulators are located on the side of high voltage (input). Many dimmers can be connected to one dimmer simultaneously, such as electronic transformers. Naturally, there are typical schemes for including such devices without regulators. Remember the important condition: the electronic transformer can not be started without load. You should also pay attention to the power. Modern leading companies produce electronic transformers at a power of 60 to 250 watts.
The device itself is a two-stroke autogeneratoron a half-bridge circuit. The two arms of this bridge are transistors. The other two arms are capacitors. That's why such a bridge is called a half bridge. In one diagonal, the voltage is applied, which is rectified by the diode bridge. A load is connected to the other diagonal. To control the operation of the transistor diagonal, the windings of the feedback transformer are connected in their circuit. The voltage rectified by the bridge will charge the capacitor, and when the voltage on the capacitor reaches the limit, the diacystor will open and a pulse will be generated that starts the current converter.
With such an instrument as an electronic transformer,there are a lot of undeniable advantages. First, we should mention small overall dimensions and low weight. This gives an excellent opportunity to install an electronic transformer virtually anywhere (even in hard-to-reach places). Some modern lighting devices, which are specially designed for working with halogen lamps, already contain several built-in electronic transformers in advance. Such schemes have found their application in everyday life, for example, in the arrangement of a chandelier. Electronic transformers are now installed in furniture, for example, in cabinets, to create a backlight for hangers and shelves.
But this is far from being all areas of application of suchdevice, as an electronic transformer. For example, there are some improvements, which often do not even require the opening of the case, however, it is possible to create a switching power supply from an electronic transformer (UPS).