In recent years, many domestic power amplifier there are different degrees of 50Hz noise, while the imported amplifier is basically not hear 50Hz noise. Analysis of multiple amplifiers and found that imported AV amplifier are not using the ring transformer, and domestic power amplifier are basically using the ring transformer.

The advantages and disadvantages of the toroidal transformers are very prominent. The advantage is no magnetic gap, magnetoresistance is very small, very little leakage, less per turn, copper loss is small, high efficiency. The disadvantage is poor resistance to magnetic saturation, a little bit of DC components can cause it to work is not normal, it is best used to transform the pure AC signal.

toroidal transformers manufacturer without load or with a pure resistance load, in the absence of magnetic saturation, the magnetic leakage interference is indeed small, but because of environmental reasons, it is not up to this condition.

The EI-shaped transformer core pairs of plug, constitute a small air gap, strong magnetic saturation, used in the usual rectifier capacitor input load circuit, the magnetic radiation interference is much smaller than the ring cattle.

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