How to Wind a Toroidal Transformer?
Most electronic devices need a certain form of power supply which differs from that which comes from the electrical network. A Toroidal Transformer is one kind of such a unit. The system was widely used in various electricity, electronics, and radio engineering sectors. Transformers are most commonly used in electrical networks and other forms of electronic equipment in power supplies.
Design and principle of operation
Transformer-the word name comes from the transformer of Latin, which means transforming in English. The widely accepted definition for this is as follows: a transformer is a device that, using the electromagnetic induction phenomenon, is capable of raising the amplitude of voltage without altering the signal shape and frequency.
A transformer is an electrical system with the assistance of which the alternating electrical voltage decreases or increases. This style of transformers is called step-downs or step-ups. It should be noted that there are also certain devices that leave unchanged the value of the sinusoidal signal, called galvanic or throttle.
Each transformer in its nature includes the following components:
- Magnetic Circuit (core);
- Frame for the winding position;
- Various additional elements like fastening brackets, contact output strips, etc.
In fact, the transformer has two or more inductive coupling windings. They are available in both forms of wire and tape and are often covered with an insulation sheet. The windings are mounted on a magnetic circuit made of soft ferromagnetic. The primary winding is connected to the source of voltage and the secondary to the charge.
The general operating principle of the system, whatever its form and intent, is as follows. The alternating signal is applied to the device’s primary winding, resulting in the presence of alternating currents within it. In addition, this current generates an alternating magnetic field in the center, under which operation a varying electromotive force (EMF) occurs in the windings. Once the charge is attached to the secondary winding, it continues to flow by alternating current. The winding the signal is being applied to is called a key. A winding that is connected to a charge is called secondary.
Toroidal devices are differentiated from those using air and liquid refrigeration according to the cooling process. There are also transformers with a hybrid refrigeration-liquid-air.
The device’s principal technological parameters include:
- Value of input voltage: The permissible value of voltage given to the main.
- The voltage exit is magnitude. The ratio of transformation is defined by this.
- Transformation Process. Signal levels rise or decrease.
- The phases total. These are split into single-phase or three-phase, depending on the network in which the transformers are used.
- The winding number. Single winding or multi-winding devices are available.
The device’s key parameters include measured power and transformation ratio. Power metering machine volt-amperes (VA). The transformation ratio shows the voltage level ratio at the device’s input to its output. The value is directly proportional to the ratio of primary to secondary turns.
As geometrically representing a toroidal is used as the basis in a toroidal transformer. The benefit of this type of magnetic circuit is that the transformer is easily rewarded with your own hands and obtained the highest output coefficient (COP) compared with other types of transformers with the same overall values.
Learn More about Our Products: Product Catalogue for Types of Magnetic Core
Calculation of Winding Parameters
Before winding a toroidal transformer at home, the measurement of its values is necessary. You’ll need to learn the root data to do that. These include exit voltage magnitude, core outer and inner diameter.
The power of the device is determined by the product of the areas S and So, multiplied by the coefficient: P = 1.9 * S * Sok.
The cross-sectional area is calculated by the formula: S = h * (Dd) / 2, where:
- S – sectional area;
- h is the height of the structure;
- D is the outer diameter;
- d is the inner diameter.
To calculate the window area, the formula is used: Sok = 3.14 * d2 / 4.
The number of turns in the secondary winding is equal to the product W2 = U2 * 50 / Sok.
This technique of calculation can be applied to almost any kind of toroidal transformer. But there is a method for the estimation of certain products.
Making a toroidal transformer with your own hands is not difficult, but you do need to perform a calculation before its manufacture. Such a measurement in relation to the product’s design features varies from the commonly accepted one. It starts with the secondary current (amperes unit) necessary value: Iam= Iper / Iw, where:
The step-by-step calculation process looks like this: for example, a ferrite ring is taken from 2000hM, for example, 20 ~12×6.
Thunder 100 wire flips. These turns constitute secondary winding, while the main is only one turn of wire that goes through the ferrite.
In the secondary the current value would be: I / Ktr= 5/100= 0.05 A. Where Ktr is the coefficient of a transformation of the transformer (the ratio of main to secondary windings).
It’s better to find a realistic example of a home-made current system to figure out how to do the calculation correctly. Suppose you need to get 4 volts at the current device’s output and limit the current to 5 amperes.
The load shunt magnitude is determined by the law of Ohm: R= U / I. The result is R= 4 / 0.05= 80 Ohms.
For any necessary parameters, you can then perform the calculation. No matter the current form at the origin, the voltage at the present device’s output is still bipolar. It is the resistance, not the diode, which is used as the secondary winding shunt. If a diode is required, then a resistor is connected first, and then a diode or diode bridge is connected. The resistance is used in the Bridge diagonal in the second example.
DIY Your Toroid with Winding Machine
One idea is to make a system fitted with an adjustable stacker and a revolution counter using the bicycle wheel concept.
The wheel is mounted on a pin in the wall, while its rim is covered with a rubber ring. Then put the core on the bottom, you need to cut it first, and then fasten it again, making a solid circle. Having wound it on the necessary length of wire, one end of it is attached to the freely placed core at the bottom. The coil moves in full circles around the rim resulting in the wire being laid on the frame. At the same time, the velocity is calculated using a bicycle counter.
A variety of devices are used to convert current today. A toroidal transformer is the most common device that is used not only for a welding machine. Winding a toroidal transformer is considered a popular service.
Learn More: Automatic Core Winding Machine and its Types
It was Faraday who made this beautiful transformer. Toroidal Transformer is a system specially built to convert AC. They can be used in a number of linear installations. This electromagnetic system can be both single and three-phase.
In this photo you can see that the design consists of the following elements:
- A metal disk that is made of rolled magnetic steel.
- Special rubber pads.
- The conclusions of the primary winding.
- Secondary winding.
- Insulation, which is located between the windings.
- Shielding and winding.
- An additional layer, which is located between the primary and the shielding winding.
- Primary winding.
- Core insulation.
- Toroidal magnetic core.
- Layer to cover insulation.
To connect the windings, the manufacturer uses a magnetic circuit. This type of converter qualifies for purpose, cooling, and type of magnetic circuit. By appointment, it can be divided into pulses, power and frequency converters for cooling transformers, air or oil.
The converter can be used on halogen lamps as a mains transformer, charger, or block. You can read about the operating principle of a current transformer if needed.
Winding toroidal transformer
Even a young electrician can manufacture a toroidal transformer. Here’s a guide to help you learn how to wind a toroidal magnetic circuit for a semi-automatic device:
- You need to use a special machine to wind the transformer on a ferrite core. This helps you to speed up the job considerably and at the same time, you can quickly take the risk of an iron jump.
- You need to ensure when winding, that there is no free space between turns. If the power transformer has small gaps then another transformer will fill them with iron sheets.
- Specific assumptions have to be welded after winding iron. 2 or 3 welding dots would be necessary to weld the component.
- Now you need to apply epoxy glue to the ends of the magnetic chain. The edges can be rounded if necessary.
- The amplifier will be covered in insulation. You may use a sheet of cardboard to conduct the winding. It can be covered with masking tape. It is important to replicate the action in the cardboard.
- Now you can wind the electrical tape, made from textiles. You may use masking tape over the sheet as well.
- The final stage involves winding the selected cross-section wire. Using a special program, you can compute the number of turns. After
- The toroidal transformer insulation has to be constructed from varnish or silk paper. This winding is called secondary and should be varnished as well. This will continue until the necessary number of turns is reached.
- The secondary winding wire usually has a broad cross-section. If an arc welding mains transformer is needed then add the necessary number of turns at the top.
This allows you to render a 220 by 24 volt toroidal transformer independently. This circuit can be easily linked, for both arc and semi-automatic welding. All parameters have to be determined according to the wire cross-section. The device’s features also allow for step by step adjustment. The very high efficiency and availability can be found among its advantages.
Here is a step by step video tutorial from Youtube