To significantly improve the safety conditions of electrical systems and lighting circuits, in many cases it is recommended to use lamps with a voltage significantly lower than that used in a standard network (220 V). Typically, such lighting is arranged in basements, bathrooms, cellars and other wet areas. For these purposes, today the so-called halogen lamps are used, the operating voltage of which is 12 V. To power lamps of this kind, a device such as an electronic transformer is used. This device is capable of transforming the mains voltage of 220 V into 12 V (optimal for the operation of a halogen lamp).
If you look at the electronic transformer, you can understand that its external device is quite simple. It is a small plastic or metal box, from which there is a conclusion of four wires:two incoming (labeled 220V) and two outgoing (labeled 12V).
The principle of operation of such a device as an electronic transformer is quite simple. Brightness control is carried out using thyristor controllers (they are called dimmers). These regulators are on the high voltage (input) side. Many devices such as electronic transformers can be connected to one dimmer at the same time. Naturally, there are typical schemes for switching on such devices without regulators. An important condition should be remembered: the electronic transformer must not be started without load. You should also pay attention to power. Modern leading companies produce electronic transformers with power from 60 to 250 W.
The device itself is a push-pull self-oscillator on a half-bridge circuit. The two arms of this bridge are transistors. The other two arms are capacitors. That is why such a bridge is called a half-bridge. A voltage is applied to one diagonal, which is rectified by a diode bridge. The 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 dinistor will open and a pulse will be generated that starts the current converter.
A device such as an electronic transformer has a lot of undeniablemerits. First, we should mention the small overall dimensions and low weight. This gives an excellent opportunity to install the electronic transformer virtually anywhere (even in hard-to-reach places). Some modern lighting fixtures that are specifically designed to work 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 construction of a chandelier. Electronic transformers are now installed in furniture, for example, in cabinets, to create lighting for hangers and shelves.
But these are far from all areas of application of such a device as an electronic transformer. For example, there are some improvements that often do not even require opening the case, however, they allow you to create a switching power supply from an electronic transformer (UPS).
