The Magnetic Amplifier – A Lost Technology of the 1950s

Re:The Magnetic Amplifier – A Lost Technology of the 1950s by Animats on Thursday June 18, 2020 @02:23AM (#23560325)

Power control for serious power was really hard until about 30 years ago, when power MOSFETs and IGBTs got good. There were a long series of not very good devices from 1900 on. Ward-Leonard drives, dynamotors, magnetic amplifiers, motors with multiple switchable windings, thyatrons, ignitrons, silicon-controlled rectifiers... People needed smooth control of high power, but it wasn't easy to get.

Now you can get IGBT modules able to handle the power for a locomotive motor. They're not that big - you can hold one in your hand. The next thing seems to be going back to MOSFETs, but in silicon carbide. Tesla switched from IGBTs to SIC MOSFETs. At last, high power control is a solved problem.

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by 082349872349872 on Thursday June 18, 2020 @04:31AM (#23561029)

Now locomotive power engineers can even have fun turning bugs (harmonics in the audio range) into features (solfege):

https://www.youtube.com/watch?v=_iLrXDU31Dg

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by VBprogrammer on Thursday June 18, 2020 @07:23AM (#23562010)

For anyone else wondering what's going on there, certain types of semiconductors have a minimum off time. They have to work around this by varying the frequency of the PWM. Usually it results in a kind of space age sound as they accelerate. In this case they have chosen something more interesting.

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by blueprint on Thursday June 18, 2020 @02:34AM (#23560380)

yeah but what are the specific benefits of magnetic amplifiers that you cannot get from SICMOSFETs

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by exmadscientist on Thursday June 18, 2020 @05:11AM (#23561255)

Not much. There's a reason they're largely forgotten!

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by vibrolax on Thursday June 18, 2020 @01:24PM (#23565342)

I guess there are fewer ways to destroy stacks of laminations and copper windings. But that doesn't make up for the extra weight, space, cost, and labor to manufacture them

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by jiofih on Thursday June 18, 2020 @10:38AM (#23563485)

You can build one at home?

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by blattimwind on Thursday June 18, 2020 @06:34AM (#23561761)

Overload resistance and overall robustness.

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Re:The Magnetic Amplifier – A Lost Technology of the 1950s by Animats on Thursday June 18, 2020 @02:29PM (#23566080)

A lifespan of a century or more?

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