[ExI] not that rare earth (part 2 of at least 2)

[Keith Henson]

The worst course I had was a controls course.  At the time, I was
working part-time for a geophysics company and lashing up a 400 Hz 20
kW aircraft generator to a VW engine to power field equipment.  So I
asked the instructor how I should go about controlling the speed of
the engine.  His response was, "That's a real-world problem; we don't
work on those".  Needless to say, my enthusiasm for the class
vanished.

A friend of mine suggested a phase shift circuit, 4 1/2 henry
inductors, 4 1/2 mfd capacitors, which gave a 180-degree phase shift
at 400 Hz.  I wired one phase of a two-phase motor to the 400 Hz power
and the other to the phase-shifted 400 Hz.  The geared-down motor ran
a link to the carburetor.  Zero to 15 kW, the generator dropped about
5 Hz.  Impressive sound for a VW engine running at 4000 rpm.

They used it for years.

Keith

On Tue, Nov 4, 2025 at 4:37 AM John Clark via extropy-chat
<extropy-chat at lists.extropy.org> wrote:
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> On Mon, Nov 3, 2025 at 11:59 AM <spike at rainier66.com> wrote:
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>>  > Yesterday we were told the Mountain Pass facility had its environmental permits in place and would be producing all we need in two years.
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> I wish them well, but until very recently that mine shipped all the ore they dug out of the ground to China for refining, it remains to be seen if they have the skills to perform that delicate chemical process on an industrial scale that is economically viable. And in two years, three at the most, we will know if China or the US won the AI race, or if neither country won and the only winner is the AI.
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>> >  we saw what happens when local grids rely too much on wind power: the huge cold front on 7-8 December 2017 caused shortages in availability in Texas.
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> A two day shortage eight years ago is not sufficient for a blanket condemnation of wind power, and I can't help but wonder if your dislike of it is just a reflection of He Who Must Not Be Named dislike of it. And Texas is unique, it is the only state in the lower 48 that insisted on having its own power grid, so it will not give power to nearby states when they run into temporary electrical shortages, and they cannot borrow power from nearby states when they temporarily run low on electricity. Iowa gets 63% of its electricity from wind power and they seem to be very happy with it.  China has also embraced wind power.
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>> > Power prices doubled since 2017.  Keith you and I never noticed our power bills back then.  We do now.
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> It's not just you two, I predict that the power bills of everybody in the US are going to skyrocket in the next few years due to AI's insatiable demand for electricity and the fact that the US has not increased its electric power generating capacity in over a decade.
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>> > Power distribution seems simple enough in theory, but it boggles the mind in actual practice.
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> When I was in college the most difficult course I had was not the one on electromagnetic theory or the one on the quantum mechanical nature of transistors, it was but one on how real world (not the simplified idealized examples seen in beginning textbooks) transformers, electric motors and generators affect large scale power distribution. I vividly remember the semi hysterical laughter that came from the entire class when they got their first look at the final exam questions. About an hour after that test I got the worst headache of my life, I don't think it was a coincidence.
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> John K Clark
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