Motors Big and Small (1971) [video] | Hacker News Reader

Motors Big and Small (1971) [video]

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37 pointsmontalbano15 comments

Many people have seen big advancements in electric motors in the last ~50 years. More power in the same space. More efficiency. Etc.

However, this is deceptive. In fact, most of the advancements in electric motors are in fact advances in electric motor controllers. Having a more advanced controller allows uses of configurations previously impractical (eg. BLDC motors). It also allows increased efficiency.

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.

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.

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.

Absolutely! I've been trying to find lower cost motors for use in building musical instruments, and I keep going back to IQ Vertiq motors because the builtin ESC has firmware based anti-cogging, which creates super smooth motion that I haven't found any other way of achieving with a brushless motor. It's all about the ESCs!

Look into the SimonK firmware, and related, which can be flashed onto a large number of cheap, off-the-shelf brushless controllers to add (configurable) niceties like this, soft-starts, braking, etc.

There have been huge advancements in the non-conducting materials used that let them run faster and hotter (which reduces the amount of conducting material you need for a given output).

yes, it's impossible to point to a single improvement in motors, because it's come from FETs, control algorithms, power sources, source code sharing, algorithm sharing, testing strategies, materials, manufacturing practices, and more. They're all working synergistically.

Did you not understand what I just said?

There have been several improvements to the physical construction of the motors in several areas that allows them to perform better/cheaper.

Even for a dumb 12VDC motor that gets turned on by a switch this has increased performance.

Previously discussed in https://news.ycombinator.com/item?id=13825078 but seems that it was worth a repost.

You might want to edit the title to insert the missing initial "P"

Thanks! The submitted title was "Rofessor Eric Laithwaite: Motors Big and Small", but rather than correcting the typo, I think we can move Professor Laithwaite to the background. Not that he isn't important, but HN titles tend to be better when they focus on content rather than personalities.

That was the year 1971. We still use the almost 100-year-old combustion engine 50 years later. There is a huge problem in the world.

The electric motor was never the problem, practical batteries are.

The electric motor used in today's EVs are basically perfect, with some reaching 99% efficiency and being capable of outputting more torque then any vehicle will ever need. All while being cheaper, lighter and more compact than any comparable ICE.

However, the bottleneck for EVs have always been the batteries. In weight, size, price, safety and usable range, a tank of fossil fuel will always beat a battery, even with the limited efficiency of an ICE.

There isn't much more to gain in electric motor design (at least not for use in road vehicles), but there is still a long way to go in battery design.

One of the top comments on the youtube video:

> That was 1971. Now 43 years later, we still use the over 100 years old combustion engine. Something is seriously wrong in this world.

Sure the physics hasn't changed but there is a huge difference between 1970 and now in how both ICEs and electric motors are constructed. Modern chemical science and engineering processes have made a huge increase in our ability to get more results within given constraints. Go crack open an ancient power tool or appliance if you don't believe me.

and the bicycle frame diamond shape was invented in 1885.

Don't create a new account to farm YouTube comments.

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