The transformer is an electric device which will transform one alternating voltage to another, for example from 220 V. in 12 V. is a lowering transformer. The simplest transformer consists of a magnetic conductor and windings which are reeled up on it: primary and secondary. On primary winding the alternating voltage moves, for example, 220 volts from network, and in a secondary winding, by means of inductive communication are created other alternating voltage. Output voltage, depends on the difference of rounds of primary and secondary windings.
Instruction
1. It is the best of all to show calculation of the primitive Highway-shaped transformer on an example. Let's say you need to calculate the transformer with parameters: mains voltage of U1=220v; output voltage (tension on a secondary winding) U2=12B; i2=0.5A load current. At first determine output power: P2=U2*i2=12*0.5=6Vt. For such power it is possible to take a magnetic conductor with a section about four square centimeters (S=4)
2. Further calculate how many it is required rounds for one volt. For the Highway-shaped transformer there is a formula: To = 50/S=50/4=12.5 rounds on volt.
3. Then, calculate quantity of rounds of primary winding: W1=U1*K=220*12.5=2750 rounds. And quantity of rounds of a secondary winding: W2=U2*K=12*12.5=150 rounds.
4. After that, define current in primary winding: i1=(1.1*P2)/U1= (1.1*6)/220=30ma. And then it will be possible to count diameter of a wire of primary winding without isolation. The fact is that the maximum current for a copper wire makes 5 amperes on square millimeter therefore: d1=5A / (1/i1) = 5A / (1/0,03A) =0.15mm.
5. And the last, calculate diameter of a wire of a secondary winding by a formula, d2=0.025*koren square of i2, substitute i2 value in this formula in milliamperes: d2=0.025*22.4=0.56mm.