DC machines can be classified as self-excited, separately excited, permanent magnet (PM), and brushless. Self-excited machines can be further classified as shunt, series, and compound. Compound ...

Craftsmen in ancient China were using complex machines to work jewellery long before such devices are traditionally thought to have been invented. Dr Peter Lu claims spiral grooves on 2,550-year-old ...

Explains how simple machines, such as levers, pulleys, wheels and axles, and inclined planes, work together to make tasks easier by trading force for distance or vice versa. It illustrates the concept ...