A transformer is such an electromagnetic device with two or more inductively connected windings, which serves to change the value of an alternating current. Many fans use transformers based on spent appliances. They are needed to power the control circuits, as well as for lighting in various electrical appliances.
Many have to deal with current transformers, so very often it is necessary to calculate the parameters of a transformer. Today you will learn how to calculate toroidal transformers and other types of devices, what parameters are used for such calculations online.
Content

1 Transformer and its design features
 1.1 Video: Toroidal Transformer

2 Transformer classification
 2.1 Initial data for the calculations of toroidal transformers
 2.2 Peculiarities of transformer calculations online
Transformer and its design features
Such a device as a transformer includes the following components: a core (magnetic wire); winding placed on it.
The winding, which is connected to the source of the transformed voltage, is called primary, and the one to which the sources of energy consumption are connected is, respectively, secondary. To destination transformers are:
 impulse;
 power devices;
 coordinating.
The required calculations for instruments based on old devices with their own hands are almost impossible to carry out, since extremely difficult to find the right iron and winding wire. Therefore it is necessary to take a magnetic wire with a power that exceeds the needs and increases the size of transformers.
Video: Toroidal Transformer
Transformer classification
Magnetic cores by their design are: armored; pivotal; toroidal. Core construction It works in such a way that the windings and the two coils are divided in two and connected in series.
There may be problems with the winding direction of the coils and their subsequent connection, although thanks to this design you can reduce the height of the device due to its horizontal placement. Basically, core magnetic circuits are used when working with the most powerful transformers.
Armor design is the most common, it has one coil, which is very convenient to wind. It can be used for lowpower and mediumpower devices, which most often have amateurs.
Toroidal design the wire looks like a ring on which windings are wound. Of all three designs, magnetic radiation in this case is minimal. This design is used infrequently, since there may be difficulties with the winding.
Below we consider what should be considered when calculating armor and toroidal transformers. Let's start with the calculations for transformers with an armored magnetic circuit. The key goal of the calculation is optimal use of the device.
The main parameter of the calculation is voltage. The output current is also calculated, and after determining the results, a decision will be made on whether or not the magnetic core is suitable.
The baseline data are as follows:
 Frequency.
 Input and output voltage.
 Output current
 Magnetic wire dimensions.
Everything measurements are carried out in centimeters. And as a separator of whole and fractional numbers, a point is used when you perform calculations using special programs. Enter the output voltage and calculate the data.
Initial data for the calculations of toroidal transformers
So, we found out what source data should be used when calculating the parameters for transformers with an armored magnetic wire. And now let's find out what data should be used to determine the indicators for the toroidal design:
 The voltage of the primary and secondary windings. This indicator is equal to U 1 = 220 B and U2 = 36 V, respectively.
 Indicator current of the secondary winding 4A.
 The core diameters are 110 mm external and 68 mm internal.
 Its height, which is 60 mm.
So, when you have the initial data for the calculation and you have found a suitable online calculator for their implementation, then you can get optimal design figures for a particular magnetic wire that your transformer is equipped with.
However, it often happens that the wires with a diameter that is one hundred percent consistent with the calculated parameters simply do not happen. To solve the problem, you can use a wire with a diameter slightly less than the ideal indicator.
And if you take a wire whose diameter is slightly larger, then the windings may simply not fit in the window of the magnetic wire.
Peculiarities of transformer calculations online
Calculations of indicators with the help of special online calculators are good because they significantly reduce the time to develop a project, as well as do experiments with parameters.
Similar programs very comfortable to use, they will help you to calculate everything simply and quickly, all you need to do is to fill in all the cells and press the miscalculation button.
Thanks to the programs, you can more easily design transformers for different voltages and capacities, and also find out exactly how this device works and what it consists of.
As a rule, the program fields have different colors:
 Light blue fields  the original design data.
 Yellow cells are data that is automatically selected from the tables.
 Green field  the final value.
If you check the box to adjust the value, the yellow field becomes light blue and you can enter your own value there.
The advantages of online calculators of transformers are as follows:
 no need for independent complex calculations;
 the ability to wind the device for those or other purposes;
 the ability to determine the parameters of the size of the core;
 the possibility of calculating the parameters in a simplified mode;
 cope with the calculations can anyone, even a novice radio amateur;
 availability of instructions;
 calculation is done by pressing just one button.
Now you should not be afraid of the difficulties of parameter miscalculation, if you took the old transformer for work, because special programs, you can calculate all the parameters that allow you to use it safely.
Naturally, it will be difficult to pick up wires of ideal size, so you need to choose those that are as close as possible to the desired dimensions.