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Comment by Animats | Hacker News Reader

Well, sort of. Faraday invented the first thing that would sort of rotate given electrical power. It took another 33 years before someone built something that had useful torque at the output shaft. Along the way, coils and commutators had to be developed. It also took a while to realize that generators and motors are basically the same.

Rotating electrical machinery was considered a solved problem and kind of boring until about 20 years ago. Then people started using semiconductor switches to drive electric motors. Classic theory assumed you were driving motors with a sine wave. Motor controllers tried to make motors happy by providing a sine wave, or something close to one. Gradually it was realized that motors could be purpose designed for chopped waveforms. This broke all that beautiful closed-form math and charts on polar graph paper that goes back to Tesla. You have to simulate to design a modern electric car motor.

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Shoulders of giants.

Faraday was the first to demonstrate an actual physical process where electrical energy was converted to mechanical energy.

It's turtles all the way down.

Interestingly electrostatic motors (albeit very weak ones) predate Faraday's invention by decades. Ben Franklin even designed one [1].

In the early days of electricity research, static electricity was more common than "current" electricity. There were early static-based telegraph experiments that predated Morse [2] and used a silk thread as a conductor. Before the electromagnet was invented, people didn't know how to build an indicator based on electric current - one concept was to use electrolysis and look for bubbles.

[1]: https://hackaday.com/2017/10/03/ben-franklins-weak-motor-and...

[2]: https://physicstoday.scitation.org/doi/full/10.1063/PT.3.307...

It starts with Hans Christian Oersted deciding to place a compass next to a current carrying conductor.

Its such a simple thing but no one had thought of a reason to do such a thing.

What happened to the compass shocked the world and triggered Faradays many beautiful experiments.

Ampere, Volta, Galvani, Ohm - so much of the modern world unfolding in just a few decades of discovery, when people still worked by the light of candles and oil lamps and it could take years for information to travel.

We were using SCR (silicon controlled rectifier) based motor drives in industrial settings at least 35 years ago. (I graduated as an Electrical Engineer in 1985 and were commonly using them then)

> Motor controllers tried to make motors happy by providing a sine wave, or something close to one. Gradually it was realized that motors could be purpose designed for chopped waveforms.

Marginally related: it was quite a shock to me when I first learned a rocket engine's thrust can be PWM-controlled.

it was quite a shock to me when I first learned a rocket engine's thrust can be PWM-controlled.

The thrust of the pistons of a steam locomotive is PWM-controlled. That's what all the elaborate levers and cranks on the side of the locomotive do. They control the "cutoff" point in the cycle, where steam is turned off. Look up "valve gear" if interested.

Sorry I may have misunderstood - is an electric car motor fundamentally different in some way from the one I learnt back in school? (I ask honestly as I find that my education may not have taught me everything)

Fundamentally, no. It's all about controlling the field effect more precisely now. See:

https://en.m.wikipedia.org/wiki/Reluctance_motor

Teslas have a:

"“Switched Reluctance motor, using permanent magnets.” ...“Tesla calls it a PMSRM, Permanent Magnet Switched Reluctance Motor."

https://cleantechnica.com/2018/03/11/tesla-model-3-motor-in-...

It is likely that the Tesla motor has a clever geometry for achieving low torque ripple and high efficiency, but combining switched reluctance and permanent magnets in the same motor is nothing new.

This combination has been used for many decades in the so-called hybrid stepping motors, where "hybrid" means that both PM and SR are used.

In the case of stepping motors, the advantage of the combination is to provide in the same motor both very small steps and also a static torque, i.e. the motor can maintain a position even without the power supply.

Depends what you were taught in school, but somewhat: they're different from the old DC motors with brushes and commutation that you might have had in childhood toys.

> I ask honestly as I find that my education may not have taught me everything

Side tangent: would you say your education overall gave you a good base to build on? If yes, what sort of curriculum were you taken through?

If you only know about one type of electric motor, then yes a lot of motors are different than the one you learned about in school. Induction machines, synchronous machines, steppers ,bldc machines, small universal machines etc... There is a world of different motor windings and rotor configurations out there for all kinds of different purposes.

> coils

When were adequate insulators for wires developed? You need that for coils. From what I read, the first technology that used insulation was telegraphy, in the 1840s.

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