Advantages of toroidal transformers

Transformer is a static electromagnetic device that makes the conversion from electrical energy to magnetic energy and to electrical energy again, and then transfers electrical energy from one circuit to another.

Transformer plays an important role in the circuit, such as isolation, voltage conversion, impedance matching, noise wave filtering, and surge protection and so on. It is widely used in household appliances, lighting power supply, audio power supply, power adapter, industrial control power supply, DC inverter, UPS, EPS/ compensation voltage regulator, new energy equipment and other industries.

The single-phase transformer with medium and small power can be divided from core structure into toroidal type (O type), EI type, R type, CD type, double column dry type and so on. Among them, the toroidal transformer is the most widely used, which has to mention the many advantages of toroidal transformer.

1. High efficiency and high performance price ratio

Toroidal core has good electromagnetic performance, like high saturation magnetic flux density, high primary inductance and large unit magnetizing power capacity, which improve the utilization ratio of the core and the winding window area, and reduce the number of turns and the direct current resistance, and also greatly improve the overload capacity and load efficiency of the toroidal transformer. Based on these conditions, the product design does not need to consider more power margin and heat dissipation conditions, and also effectively control the cost.

 

 

2. Excellent no-load characteristics

Toroidal core is wound with high permeability silicon steels, no gap on magnetic circuit, low magnetic resistance. Under the same power and magnetic field density, the no-load loss and exciting current of toroidal transformer are only 50%~70% of other transformers, which reduce the standby loss and improve the equipment operation reliability.

 

3. Low noise

There is no gap of toroidal core, the silicon steels are tightly winded, and after the vacuum impregnation with pressure it becomes a whole. Even in the middle, high magnetic frequency, it will not cause noise due to magnetic expansion. This is what the EI, dry-type and other lamination cores cannot match.

 

 

4. Low magnetic flux leakage, low leakage inductance

Toroidal core has a high saturation flux density, and the coil is uniformly distributed on the core, magnetic potential difference can effectively reduce the magnetic leakage. Normally, with the same transformer specifications, the magnetic flux leakage of toroidal transformer is only 1/10 of the EI one. The main coil is tightly and rationally layered winded, and then the leakage inductance of the primary and secondary coils can be better coupled to reduce the primary and secondary leakage inductance.

 

 

5. Safety of electrical structure

There is a certain thickness of stacked dielectric film between the core and primary coils, primary coil and electrostatic shielding, electrostatic shielding and secondary coil, secondary coil and the installation plate, which completely isolates the electrical gap and is safe without maintenance. Therefore, isolated toroidal transformers have been widely used in medical equipment transformers.

 

6. Full-band response

Toroidal core is wound with high flux and high sensitivity silicon steels. 

-The thinner steel thickness, continuous flux path and low magnetic resistance reduce the area of hysteresis loop and the eddy current loss, also guarantee high alternating magnetic field conversion cycle and efficiency (Residual magnetism will always exist, and the smaller the hysteresis curve area, the better the alternative magnetic field switching). In the medium and high frequency magnetic field, the loss is low; the signal extension and the bonding are more continuous and fluent.

-The high permeability and high sensitivity ensure the overload output 8 to 10 times of transient power (magnetizing capacity of the core is large enough and is not easily saturated) at low frequency, so it is widely used in power amplifier and audio power supply.

 

 

7. Compact size, light weight and easy installation

Design of toroidal transformer is very flexible.

-In the case of constant cross-sectional area, the OD and height can be changed to meet the installation size restrictions.
-In the case of constant load performance, by adjusting the coil and iron core to meet the requirements of size and weight.
-In general, high power toroidal transformers are 50% lighter in weight than laminated transformers and operate more reliably.