Ferrite Toroid Core: Magnesium-Zinc Ferrite, One-Day Grind, 1400 °C (Snoek 1948, Ex. II)

A soft ferrite ring core of magnesium-zinc ferrite: magnesia, zinc oxide and iron oxide ground for a whole day, pressed into a ring and fired at 1400 °C in oxygen. Snoek's ring had an initial permeability of 670 and a Curie point near 100 °C. Source: J. L. Snoek, US 2,452,530 (Philips, 1948), Example II. The violet iron oxide has its own blueprint (precipitated hematite calcined at 1000-1100 °C, after Nurdini et al. 2022); Snoek does not say how his was made. Picture: the patent's Fig. 4, the ring core.

고급

2 days

안내

Weigh 25.5 : 25.5 : 49 mol %

Mix 25½ mol % pure magnesia, 25½ mol % pure zinc oxide and 49 mol % pure violet iron oxide. Ours, by weight: 9.4 g magnesium oxide, 18.99 g zinc oxide and 71.61 g iron oxide per 100 g. Snoek does not say what makes it 'violet'; violet iron oxide has its own blueprint.

이 단계의 재료:

산화마그네슘9.4 g

산화아연 분말18.99 g

보라색 산화철71.61 g

필요한 도구:

접시 저울

방진 마스크

Grind for one day in an iron ball mill

Grind the mixture for one day in a mill with iron balls.

필요한 도구:

철 볼 밀

방진 마스크

Press a ring at 4 tons per cm²

Press the powder at 4 tons per square centimetre into a ring 3 cm across with a 4 × 4 mm cross-section.

필요한 도구:

유압 프레스

링 프레스 다이

방진 마스크

Fire 1 hour at 1400 °C, cool slowly in oxygen

Heat the ring in oxygen for 1 hour at 1400 °C, then cool it slowly in oxygen. Snoek's ring had an initial permeability of 670 at room temperature and 2 kHz.

필요한 도구: