How to calculate transformer

Power transformers are an inherent part of the power lines, Railways and industrial enterprises, as well as elements of the landscape of any city. Thanks to them, there is the possibility of more economical transmission of electricity over long distances, and then convert it to a level that is acceptable in the home. For such purposes, use the raising and lowering of the power device.

Instruction

1. Calculate max load current (I n) and the voltage across the second winding (U2). To do this, use the formulas. The current through the II-th winding of the transformer:
   I_2=1.5 N ,
   where I_2 is the current through the windings of the 2nd transformer, And;
   N - maximum load current, A.
   The power consumed by the rectifier from the second winding of the transformer:
   R(2 )= U_2 I_2 ,
   where: U_2 - the voltage on the second winding;
   I_2 - max II is the current through the second winding of the transformer A.
2. Make counting of transformer capacity:
   P_mp=1.25P_2 ,
   where P_mp - power transformer, W;
   P_2 is the maximum power that is consumed from the second winding of the transformer, VT.
   In that case, if the transformer is several of the secondary winding, then calculate the total capacity and then the total capacity of the transformer itself.
3. Find the value of the current that flows in the I-th coil:
   I_1=P_mp U_1 ,
   where I_1 is the current through the winding 1,And;
   P_mp - estimated the power transformer, W;
   U_1 - voltage of the I-th winding of the transformer (grid).
   Area, which is required for the core section of the magnetic circuit:
   S=〖is 1.3*〖(P〗_mp〗^(1/2)) ,
   Where: S is the cross section of the core magnetic circuit 〖cm〗^2;
   P_mp - transformer wattage.
   The number of turns of the primary(network) winding:
   W_1=50U_1/S
   where W_1 is the number of turns of the winding;
   U_1 - voltage of the I-th winding, V;
   S is the cross section of the core magnetic circuit 〖cm〗^2.
4. Count the number of turns in the second coil:
   W_2=55U_2/S
   where W_2 is the number of turns of the winding;
   U_2 - the voltage on the second winding;
   S is the cross section of the core magnetic circuit 〖cm〗^2.
   The diameter of the wire winding of the transformer define as:
   d=0.025*I,
   where: d-wire diameter, mm;
   I is the current through the winding, mA.
5. Pick up after calculation of transformer iron and wire, mount the frame and fabricate the coil. Note that the transformer plate W-shape may have a different area of the window, so you need to check whether the wires are placed on the frame of the transformer, if the plates are chosen. To find out, you need a power transformer, which we previously learned to multiply by 50, this value will characterize the desired area of the window in 〖mm〗^2. This iron can be used in the transformer if the value is greater than or equal to the area in the selected plates. Making a choice of a core of the magnetic circuit, keep in mind that the ratio of the thickness of the set (the ratio between the sides of the core) and the width of the core should be in the range from 1 to 2.