The transformer is a unit designed to transmit electricity with changed indicators over the network to the end user. This equipment has a specific pattern. Transformers can lower or increase voltage.
Over time, the core may need to rewind. In this case, the radio amateur is faced with the question of how to wind the transformer . This process takes a lot of time and requires concentration. However, there is nothing complicated in rewinding a circuit. There is a step-by-step instruction for this.
Design
The transformer operates on the principle of electromagnetic induction. It can have a different design of the magnetic drive. However, one of the most common is a toroidal coil. Its design was invented by Faraday. To understand how to wind a toroidal transformer or device of any other design, you must first consider the design of its coil.
Toroidal devices convert the alternating voltage of one power to another. There are single-phase and three-phase designs. They consist of several elements. The structure includes a core made of ferromagnetic steel. There is a rubber gasket, primary, secondary winding, as well as insulation between them.
The winding has a screen. The core is also covered with insulating material . A fuse and fasteners are also used. To connect the windings into a single system, a magnetic drive is used.
Winder
Toroidal transformers can be of different types. This must be considered when creating a path. You can wind the transformer 220/220 , 12/220 or other varieties using a special tool.
To simplify the process, you can make a special apparatus. It consists of wooden racks, which are fastened together by a metal rod. It has the shape of a hilt. This skewer will help to quickly wind the contours. The twig should not be thicker than 1 cm. It will penetrate the frame through. Using a drill to complete this process will be easier.
The drill is mounted on the plane of the table. It will be in parallel. The handle should rotate freely. The rod is inserted into the drill chuck. Before this, you need to put on a block with a frame of the future transformer on a metal pin. The rod may be threaded. This option is considered preferable. The block can be clamped on both sides with a nut, textolite plates or wooden planks.
Other tools
To wind the transformer 12/220, pulse, ferrite or other types of designs, it is necessary to prepare several more tools. Instead of the design presented above, you can use an inductor from the phone, a device for rewinding a film, a machine for a spool with a thread. There are many options. They must ensure a smooth, uniform process.
You will also need to prepare the device for unwinding. In principle, such equipment is similar to the devices presented above. However, in the reverse process, rotation can be made without a handle.
In order not to count the number of turns on your own, you should purchase a special device. It will take into account the number of turns on the coil. For these purposes, an ordinary water meter or a bicycle speedometer may be suitable. Using a flexible roller, the selected meter is connected to the winding equipment. You can count the number of turns of the coil orally.
Calculations
To understand how to wind a pulse transformer, it is necessary to make calculations. If you rewind an existing coil, you can just remember the initial number of its turns and purchase a wire of identical cross section. In this case, you can do without calculations.
But if you want to create a new transformer, you need to determine the quantity and type of materials. For example, for a device with a working load of 12 to 220 V, a device of 90 to 150 W power is required. You can take a magnetic drive, for example, from an old TV. The conductor cross section is determined in accordance with the power of the unit.
The number of coil turns is determined for 1V. This indicator is equal to 50 Hz. Primary (P) and secondary (B) windings are calculated as follows:
- P = 12 x 50/10 = 60 turns.
- B = 220 x 50/10 = 1100 turns.
To determine the currents in them, the following formula is used:
- Tp = 150: 12 = 12.5 A.
- TV = 150: 220 = 0.7 A.
The obtained result must be taken into account when choosing materials for creating a new device.
Layer insulation
To wrap a ferrite transformer or other kind of device, it is necessary to study one more nuance. Between certain layers of conductors, insulating materials should be installed . Most often, condensate or cable paper is used for this. All necessary materials can be purchased in specialized stores. The paper should have sufficient density, be smooth without gaps or holes.
Between the individual coils, the insulating layers are made of more durable materials. Most often used varnish. She is covered with paper on both sides. It is also necessary to level the surface before winding. If the varnished cloth could not be found, paper folded in several layers can be used instead.
The paper is cut into strips, the width of which should be greater than the contour. They should extend 3-4 mm beyond the edges of the winding. Excess material will tuck up. This will protect the edges of the coil well.
Frame
To understand how to properly wrap a transformer , you should pay attention to every detail of this process. Having prepared the insulation, wire and tool, you should make a frame. You can take cardboard for this. The inner part of the frame should be larger than the core core.
For an O-shaped magnetic drive, it is necessary to prepare 2 coils. For the core of the W-shaped form, one contour is required. In the first embodiment, the round core must be coated with an insulating layer. Only after this they start winding.
If the magnetic drive is W-shaped, the frame is cut out of the sleeve. Brushes are cut out of cardboard. In this case, the coil will need to be wrapped in a compact box. Brushes put on sleeves. Having prepared the frame, you can proceed to winding the conductor.
Step-by-step winding instruction
DIY winding the transformer will be quite simple. To do this, the coil with the wire should be installed in the equipment for unwinding. The old wire will be removed from it. The frame of the future transformer needs to be put in winding equipment. Then you can make rotational movements. They should be measured, without jerking.
During this procedure, the wire from the old coil will be moved to the new frame. The distance between the wire and the surface of the table should be at least 20 cm. This will allow you to put your hand and fix the cable.
On the table you need to lay out all the necessary tools and equipment in advance. At hand should be insulating paper, scissors, sandpaper, a soldering iron (included in the network), a pen or pencil. With one hand, you need to turn the handle of the device for winding, and with the other - fix the conductor. It is necessary that the turns fit evenly, evenly.
Winding Recommendations
Considering the step-by-step instructions on how to wind the transformer , attention should be paid to subsequent operations. After laying the conductor, the frame will need to be insulated. Through its hole, it is necessary to thread the end of the wire out of the circuit. The commit will be temporary.
Experienced hams recommend first practicing before winding. When it turns out to apply the turns smoothly, you can begin to work. The angle of tension and wires must be constant. Each subsequent layer does not need to be wound all the way. Otherwise, the conductor may slip from its intended place.
In the process of winding coils, you need to set the counter to zero. If it is not, you need to pronounce the number of turns of the wire out loud. In this case, you should concentrate as much as possible so as not to lose count.
The insulation will need to be pressed with a soft rubber ring or glue. Each subsequent layer will be 1-2 turns less than the previous one.
Connection process
Considering how to wind a transformer , it is necessary to study the process of connecting wires. If the core breaks during winding, a soldering process should be performed. This procedure may also be required if it is originally intended to create a contour from several separate pieces of wire. The adhesion is performed in accordance with the thickness of the wire.
For wires with a thickness of up to 0.3 mm, it is necessary to clean the ends by 1.5 cm. Then they can simply be twisted and soldered using the appropriate tool. If the core is thick (more than 0.3 mm), you can solder the ends directly. Twisting in this case is not required.
If the wire is very thin (less than 0.2 mm), it can be welded. They are twisted without a stripping procedure. The connection point is brought into the flame of a lighter or spirit lamp. At the junction should appear an influx of metal. The junction of the wires must be insulated with varnish or paper.
Test
Having studied the procedure of how to wind the transformer, several more recommendations should be taken into account. The number of turns of a thin conductor can reach several thousand. In this case, it is better to use special counting equipment. The winding is protected from above with paper. For thick conductor outer protection is not required.
Next, a transformer is tested. Its primary circuit is connected to the network. A lamp is connected in series with the power source. This will detect a short circuit.
In order to evaluate the reliability of insulation, it is necessary to alternately touch the output of each output of the network circuits. The verification procedure must be performed very carefully. The likelihood of electric shock should be excluded.
Having examined the step-by-step instructions for winding the transformer, you can repair the old one or create a new device. With strict adherence to all of its points, it is possible to create a reliable, durable unit.