Toroidal Transformer

Advantages of toroidal transformers

Transformer is a static electromagnetic device that converts electrical energy to magnetic energy and then back to electrical energy which is transferred between two or more circuits.

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

According to their core structure, single-phase transformers with small and medium power can be divided into toroidal type (O type), EI type, R type, CD type, double column dry type, etc. Yet, the toroidal transformer is the most widely used because of its plentiful advantages.

1. High efficiency and cost effective

The toroidal core has good electromagnetic performance of high saturation magnetic flux density, high primary inductance, and large unit magnetizing power capacity. It helps improve the utilization rate and the winding window area, reduce the number of turns and the direct current resistance, and also greatly improve the overload capacity and load efficiency of the toroidal transformer. With NICORE toroidal core, you do not need to consider the power margin and heat dissipation of your product, and you can also effectively control the cost.

2. Excellent no-load characteristics

The toroidal core is wound with high permeability silicon steels to form a closed magnetic circuit with low magnetic resistance. Under the condition of constant power and magnetic field density, the no-load loss and exciting current of toroidal transformer are only 50%~70% of other transformers. The toroidal core helps reduce the standby loss and improve the equipment operation reliability.

3. Low noise

The toroidal core is closed and tightly winded with silicon steels. It is formed after vacuum pressure impregnation treatment. Even at middle and high magnetic frequency, it will not cause noise due to magnetic expansion, which is what the EI, dry-type, and other lamination cores cannot achieve. 

4. Low magnetic flux leakage, low leakage inductance

The toroidal core has a high saturation flux density and coils are uniformly distributed on the core. The magnetic potential difference can effectively reduce the magnetic leakage. Normally, under the condition of the same specification, the magnetic flux leakage of toroidal transformer is only 1/10 of the EI's. The main coil is tightly and rationally layered and winded, the primary and secondary coils thus can be better coupled to reduce the primary and secondary leakage inductance.

5. Safe electrical structure

There are stacked dielectric films with a certain thickness between the core and primary coils, primary coil and electrostatic shielding, electrostatic shielding and secondary coils, secondary coil and the installation plate, which isolate the electrical gap completely and improve safety. Therefore, the isolated toroidal cores 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, continuous flux path, and low magnetic resistance reduce the area of hysteresis loop and the eddy current loss. It also guarantees high alternating magnetic field conversion cycle and efficiency (residual magnetism will always exist, and the smaller the hysteresis curve area is, the better the alternative magnetic field switching can be). 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  to be 8 to 10 times of transient power (magnetizing capacity of the core is large enough and is not easily saturated) at low frequency, and therefore toroidal transformer are widely used in power amplifier and audio power supply.

7. Compact size, light weight, and easy installation

The design of toroidal transformer is very flexible.

-For constant cross-sectional area, the OD and height can be customized to meet the installation requirement.

-For constant load performance, the coils and iron core can be adjusted to meet the requirements of size and weight.
-In general, high power toroidal transformers are 50% lighter in weight than laminated transformers and can operate more reliably.

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