Well-known step-up transformer ...

Each field of technology has its own iconic devices, looking at which you unambiguously understand what, where, from where. The sail is the sea, yachts, ships. Propeller - aviation, airplanes, a wheel - a bicycle, a car, etc. And not always we think about the fact that once these now simple and such understandable devices were another, sometimes difficult, step in the formation of a whole branch of engineering or engineering.

Such a story and a well-known representative of electrical engineering - a transformer. In the distant 1831 Faraday went down in history by the discovery of electromagnetic induction - the basic principle of the transformer's work. Only 45 years later a Russian scientist PN Yablochkov was granted a patent for the invention of a transformer. Two windings, located on an unclosed core, confirmed the possibility of transforming, i.e. Convert, change currents and voltages. The very first was a step-up transformer. Modern transformers have sizes from structures in several floors to tiny products less than 1 cm, and their production is the leading branch of the electrical industry.

In engineering, a huge number of transformers for various purposes are used, and each of them has its own specific name. For example, a wide application in electrical laboratories has a step -up voltage transformer, which with a voltage of several kilovolts has a supply voltage of 220 V.

So, the transformer - what is it? The classical definition sounds like this: a transformer is an electrical machine that converts the current of the input power source into a secondary winding current with a different voltage. The transformer works with AC voltage, because The induction effect is manifested only when the electromagnetic field changes . Transmission (transformation) of energy passes through the transformation of electrical energy in the windings first into the magnetic field, and then - the transition back to the electrical energy of the current, but already in the secondary winding. If the secondary winding exceeds the primary winding by the number of turns, then we have a step-up transformer, and if we connect the windings in reverse, the transformer will also be "on the contrary" - a step-down transformer.

Let's assume that it is necessary to connect an electric consumer in a garage with an electric network 36B, for example, a battery charging unit with a power supply of 220V - a typical case in order to use a step-up transformer. The solution of such a practical problem will be considered step by step.

1. The power of the charger is taken from the passport - most likely it will be something of about 100 watts. Realizing that it is always necessary to have a reserve for the future and taking into account the efficiency of a future transformer of about 0.9, we take the power of the primary winding 150 W.

2. We select the magnetic core. It's easiest to get an O-shaped magnetic core (from an old TV set). For us, anyone who has a cross section of not less than follows from the relation: P1 = S * S / 1.44, where P1 and S is the transformer power in Watts and the cross section of the core in cm2, is suitable for us. The calculation gives the value S = 10.2 cm2.

3. The next step is the most important in the "construction" of the transformer - the number of turns per 1V is determined: N = 50 / S = 50 / 10,2 = 4,9 turns / V. Now it is quite easy to calculate the number of turns (or, as they say, "winding data"), primary and secondary windings: W1 = 36 * N = 176 turns and W2 = 220 * 5 = 1078 turns.

4. Define the currents of the windings. We proceed from the fact that the power of each of the windings is approximately 150 W. In this case, the working currents of the windings: J1 = 150/36 = 4.2A and J2 = 150/220 = 0.7A.

5. Now there is all the data for determining the diameters of the wires of the windings. And we will do: for the primary winding d1 = 0,8 * √J1 = 0,8 * 2,05 = 1,64mm square. ;

Similarly for the secondary winding d2 = 0.8 * √J2 = 0.8 * 0.84 = 0.67 mm square.

To wind the windings, we choose the diameters coming from the standard ones.

All! The calculation is over, but is it possible to manufacture a step-up transformer with your own hands? As they say - there is nothing easier, if you need it badly. The real need is the main force driving self-delicacies, so that further handles, handles.

6. Two frames are made for the selected magnetic core.

7. On the skeletons with dense packing wind around half of the primary winding and insulate it with glass or lacquer.

8. Next, one half of the secondary winding is laid on each skeleton and also covered with lacquer.

9. Assembly of the magnetic circuit, the clamping of its parts with a yoke - the problem is not very complicated. When assembling the magnetic core, it is desirable to glue its halves with any composition using ferro-powder - this will eliminate the "buzz" of the device during operation.

That's all! Our homemade, it is worth thinking, will work long and in joy. And who would doubt!