To convert voltage from low to high, and vice versa, step-down or step-down transformers are used. They are electric machines with high efficiency and are used in many areas of technology.
The main parts of the design of the transformer.
Can I make a transformer with my own hands at home? What materials and devices to use in the production of such work? In order to properly assemble a step-up transformer, it is necessary to accurately carry out the entire technological process and recommendations on the assembly of this type of electrical machines, which will be given below.
What you need to know and have for self-winding transformer?
If there is a need for this device, then you need to have answers to such questions:
- What is a transformer for: increase or decrease the voltage?
- What voltages should be the input and output of the device?
- Does the device operate on AC 50 Hz or should it be relied on for a different frequency?
- What will be the power of a homemade transformer?
After receiving the answers, you can start buying the right materials. To do this, they buy tape insulation (varnished cloth) for the future transformer, a core for it (if there is a suitable power from an old, burnt-down TV, then you can use it), the necessary amount of wire in enamel insulation.
Scheme homemade devices for winding transformers.
For winding the windings, you can make the simplest winding machine. To do this, take a board 40 cm long and 100 mm wide. Two bars of 50 x 50 millimeters are attached to it with screws so that the distance between them is 30 cm. They must be drilled at the same height with a 8 mm drill. In these holes lead bar, which is previously put on the coil of the future transformer.
On one side of the pin, a thread should be cut to a length of 3 cm and a handle is attached to it with the help of two nuts, which rotates the bar with the coil when winding the transformer.
The dimensions of the winding machine described above are not critical - it all depends on the size of the core. If it is made of ferroalloys and has the form of a ring, then it is necessary to carry out the winding manually.
A preliminary calculation of the number of turns can be made on the basis of the required power of the apparatus. For example, if you need a step-up transformer from 12 to 220 V, then the required power of such a device will be in the range of 90-150 watts. Choose the O-type type of magnetic circuit from the old TV or buy a similar one in the store. Its section should be selected by the formula of the electrical reference. In this example, it is approximately 10-11 cm².
The next step is to determine the number of turns per 1 V, which in this case is 50 Hz, divided by 10-11, something around 4.7-5 units per volt. Now you can calculate the turns of the primary and secondary windings: W1 = 12 X 5 = 60 and W2 = 220 X 5 = 1100.
Then it is necessary to determine the currents in them: I1 = 150: 12 = 12.5 A and I2 = 150: 220 = 0.7 A.
Find the sections and diameters of the wires of the windings according to the formulas from the directory.
Step-up transformer is pre-calculated, you can start winding it.Back to table of contents
Workflow for making coil frames
Winding scheme of the welding transformer.
They are made of cardboard. The inner part should be slightly larger than the core core, and the cheeks should freely enter the transformer window. When using an O-shaped core, it is necessary to make two coils, and when using W-shaped plates - one.
When using a round core from LATRA, it is prewound with tape insulation and then the wire is directly started to wind on it, distributing the required number of turns over the entire ring. After the winding of the primary winding is completed, it is covered with 3-4 layers of varnished cloth and then the windings of the secondary part begin to wind on top. After this, the tape insulation closes the wire, previously brought out the ends of the windings. When using conventional magnetic cores, the skeleton of the coils is done like this:
- the sleeve is cut with cuffs on the sides of the ends;
- cheeks cut out of cardboard;
- roll the coil body along the marked lines into a small box and glue it;
- put on the sleeve the upper parts (cheeks) and, bending the cuffs, glued.
Making windings of step-up transformer
Placement of insulating circles of the electric.
The coil is put on a wooden bar with the dimensions of the core of the magnetic circuit. It pre-drilled hole for the coil winding. This part is inserted into the machine, and the winding manufacturing process begins:
- 2 coats of varnished cloth are wound on the coil;
- one end of the wire is fixed on the cheek and slowly begin to rotate the handle of the machine;
- coils should be laid tightly, isolating each wound layer from the next with a varnished cloth;
- after the primary winding is wound, the wire is cut and its second end is fixed on the cheek near the first;
- Insulating tubes are put on both leads, and outside the winding is covered with insulation;
- The coil of the secondary winding is wound in the same sequence.
Step-up Transformer Assembly
Disassemble the core. Since it is used O-shaped type of transformer iron from the TV, it is easy to do, since it consists of two halves. They put both coils on the “horns” and connect both parts of the device, clamp the fasteners.
Diagram of a single-phase transformer.
When using separate plates for assembly, first of all, by the power of the transformer, the thickness of its package and, accordingly, the required number of W-shaped or O-shaped sheets (according to the reference book) are determined. Then they are alternately inserted into the hole on the sleeve of the coil and tightened with studs and nuts (in the plates there are special holes for this).
If when switching on the transformer you hear noise or bounce, then you need to tighten the fastener tightly. This is done until the "buzz" stops. They make a test: they turn on the transformer in the network by the secondary winding - a voltage of 12 V should appear on the primary side
Leave it on for half an hour, while the device should not be heated.
If this condition is met, then the transformer is assembled correctly.Back to table of contents
Applied tools and materials
- transformer core;
- isolation (varnished cloth);
- the wire;
- thin cardboard;
- planks and wooden bars;
- steel bar;
It is easy to make the step-up transformer yourself, it is important only not to deviate from the above winding and assembly technology. Such a product with all the recommendations will work for many years.