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. Unknown: the 'violet' iron oxide, linked to an unknown head. Picture: the patent's Fig. 4, the ring core.

高级

2 days

说明

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. Unknown: what makes the iron oxide 'violet'.

此步骤所需材料：

氧化镁9.4 克

氧化锌粉末18.99 克

紫色氧化铁71.61 克

所需工具：

等臂天平

防尘口罩

Grind for one day in an iron ball mill

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

所需工具：

铁球磨机

防尘口罩

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.

所需工具：

液压机

环形压制模

防尘口罩

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.

所需工具：