The Simplest Motor

At the end of the eighteenth century, the New World was faced with the choice of the optimal way of transferring electric current from the producer to the consumer. Edison Electric Light company promoted direct current, while Westinghouse Electric and Thomson-Houston Electric promoted alternating current. The famous inventor Nikola Tesla also took part in the battle of the currents.
True, at first he worked for Edison, and then sold his patents to his competitor. But in the end, Edison Electric Light and Thomson-Houston Electric merged into General Electric, and AC gradually replaced DC from distribution networks.

This happened for two simple reasons.
The first reason is an AC transformer that converts high voltage to low voltage and vice versa. At the same time, the efficiency of high-power transformers approaches unity, which makes these simple devices ideal machines. Whereas for direct current such simple converters do not exist until now.

The second reason is the simplicity and reliability of AC motors.
Even the simplest DC motor requires three windings, a magnet and a collector, which greatly reduces the reliability of the motor.
And AC motors successfully do without collectors and magnets.

However, only 70 years after the end of the war of currents, the advantage of alternating current has ceased to look so indisputable, especially when laying high voltage power lines.

In the middle of the nineteenth century, high-voltage DC power lines, switched by mercury valves, appeared. And at present, direct current is successfully used in high-voltage power lines to save money, as well as to organize the transfer of energy between power systems that are not synchronized in frequency. Mercury valves have been replaced by thyristors and IGBT transistors in these systems.

If desired, modern high-speed MOSFET switches could provide cost-effective DC-to-DC conversion on the consumer network. But even if such a fantastic project existed, it would be too difficult and expensive to replace or modernize a billion simple and reliable AC electric motors that have been successfully working in factories, manufactory and in our homes for decades.

#motor #AC-DC