Many people have seen big advancements in electric motors in the last ~50 years. More power in the same space. More efficiency. Etc.<p>However, this is deceptive. In fact, most of the advancements in electric motors are in fact advances in electric motor <i>controllers</i>. Having a more advanced controller allows uses of configurations previously impractical (eg. BLDC motors). It also allows increased efficiency.<p>Better controllers are mostly down to the development of fast high power MOSFETs (electronic switches). They allow electric currents to be directed very precisely and with low losses, unlike previous tools of relays and mechanical switches (eg. motor brushes), which provide far less control. Combine that with microcontrollers and mathematical models of the motor executed in real time, and you can direct varying currents to each motor coil to achieve very high performance with very high efficiency.<p>One other big contributor is the development of cheap neodymium magnets, which enables stronger magnetic fields in less space, again making motors smaller and more efficient for the same power.<p>Modern motor+controller systems are now usually above 90% efficiency, and can go above 98%. So there is limited room for further improvements there, although I'm sure we'll still see them get smaller and cheaper to manufacture.
Previously discussed in <a href="https://news.ycombinator.com/item?id=13825078" rel="nofollow">https://news.ycombinator.com/item?id=13825078</a> but seems that it was worth a repost.