The Vacuum Tube’s Forgotten Rival
spectrum.ieee.org
spectrum.ieee.org
Solid state electronics, and even tubes, weren't up to the task.
Earl Pace was the Westinghouse engineer to figured out how to do it. He used a set of Synchronous AC motors to take the incoming 3 Phase, and drive a set of DC generators. The technology to control the field windings on the DC generators was just within reach. So he used the biggest SCR systems of the day to drive those. Driving the field windings allowed you to zero or even reverse the output of the generator.
In effect, it was one of the largest magnetic amplifiers in history.
Those generators then drove the DC motors on 6-stand.
Some of the control circuitry used Magnetic amplifiers when they need to have multiple isolated inputs. The amazing thing is that they can pass DC signals to about 1 khz. (They had a 10 Khz drive signal)
All of this from 1964. I repaired some of the control modules back in the 1980s, which is how I learned about it all.
Quoting a quote: I found this quote of the 1951 US manual amusing.
Much like Russian products are abhorred in America right now. Caviar, LukOil, Kaspersky AntiVirus, etc…
I don’t think people avoided these products before the Ukraine invasion.
https://www.foodandwine.com/news/stoli-vodka-stolichnaya-nam...
Caviar is the best in the world! :-)
So when you're buying an antivirus you're buying paranoia. Russian paranoia is simply much more refined and unimpregnable than American paranoia, much worse persecution, much worse consequences. It's spinal.
There's other stuff, like parachutes and ejection seats, they made much better parachutes for aerospace because they've seen uniquely fucked-up accidents like disgusting, and instead of slapping lasers and computers on everything they're more like old-school American inventors who actually used cheap cheap stuff, ideally stuff nobody wants, oh man there was tons of that in the Soviet Union! Factories producing too little of one thing, too much of the other, like the incentives didn't match up, but hey, if the inventor figures out a way to work with that, I mean of course he can't it was proven impossible BUT IF HE DOES ANYWAY, if he thinks the unthinkable, it may be the last time but it won't be the first.
In addition there was some really high quality stuff the west just refused to talk about and carried out historical and media blackouts against. So just as the Soviet Union didn't talk about the American Lunar Landing, in the west they don't talk about the Soviet Lunar Landing, 1967 I think it was? First they got a rocket to do a hard landing, but all over the nearby solar system, hard landings everywhere, largely because they had bigger rockets, much better rocketry. Then after the hard landings, soft landings, take photos of Venus on the surface (the only ones humanity has), and put this little drone car on the Moon.
The Whittle engine was a radial flow design, which was bulkier and less efficient, and was abandoned after the war.
I already knew the context: I personally know people who to this day refuse to buy German goods because of WW2.
I still find the quote amusing.
That was when I realized that it pays to keep improving on the wheel.
This chronology of AM radio is interesting: [https://web.archive.org/web/20071118155548/http://members.ao...] It mentions Fessenden's 1906 Xmas broadcast, and it looks like he'd just gotten one of Alexanderson's alternators.
Paul Mali, Magnetic Amplifiers (1960;PDF) [https://web.archive.org/web/20061114175548/http://www.pmille...]
Home-made MA's: [http://sparkbangbuzz.com/mag-amp/mag-amp.htm]
https://alexander.n.se/en/the-radio-station-saq-grimeton/saq...
Might want to get a head start on the receiving hardware, though. Most SDRs don't go that low, and though soundcards can go that high, their input impedance may not be well suited to whatever antenna you can cobble up. Oh, and you'll want an absolutely enormous antenna. Get a roll of cheap fence wire and string it halfway down the block...
https://niklasriewald.com/2020/01/02/the-math-behind-gravity...
Solid-state-punk.
For example, many stage lighting systems still use them. For example, the Sydney Opera House which opened in 1973 with the latest equipment used them for its stage lighting dimming (although they have now been replaced with solid state dimmers).
Magnetic amplifiers are wonderful devices albeit a bit slow for some applications. Moreover, unlike SCR and other solid state switching, they produce no RF switching noise.
Another reason for using magnetic amplifiers is their utter reliability - they just don't fail (being so simple). In fact, they're still used in some industrial applications specifically for that reason (unlike the Alexanderson alternator which was a monster to operate and keep reliable - but then they each served different purposes).
BTW, I'm not anti vacuum tube as for part of my career I worked with FM and TV transmitters. Even today, replacing, say, a 4CX10000D vacuum tube with a solid state equivalent is certainly no easy feat.
BTW, you'll note that after 'Gaussian' 'cgs' is in l/c, that's deliberate on my part as it's often designated that way despite the fact that the browser's speller automatically corrected it to u/c. The second instance I've left as the browser corrected it.
It was William Steagall of Sperry-Rand who realized that the flux saturation could be used as a digital logic element. If you send a pulse in the same direction as the core is already magnetized, you get no output pulse. From this, and a multi-phase clock to supply drive power, digital computing elements were created.
https://ethw.org/First-Hand:The_Naval_Tactical_Data_System_i...
A paper bag of magnetic cores disappeared while the engineers were out to lunch:
> But shortly after, the engineer called and asked if the shipment was there. This did not sound too good. With a little detective work we found a cleaning crew had worked in the office while we were gone. A little more sleuthing revealed that the bag had been accidentally knocked into a waste basket, and that load of waste had already been dumped into the plant incinerator. The incinerator ashes were spread over a concrete floor, and sure enough there were small magnetic cores, about one sixteenth of an inch in outside diameter, mixed in with the ashes. The CP-642 B had 32,768 30-bit words in its memory, meaning, with spares, there were just about one million magnetic cores in the ashes. At ten cents per core, the ashes held about one hundred thousand dollars worth of cores.
We reasoned the cores were the result of a firing process, and the heat of the incinerator probably had not hurt them. Maybe it even made them better. A quick test of some of the cores picked from the ashes revealed the cores were as good as ever. We and a contingent of Univac engineers & technicians spent a fun filled day rescuing the cores from the ashes with long needles. The cores were strung into the machine’s memory planes, and it passed all performance and environmental tests with flying colors.
That entire history is worth a read if you are interested in computer history of the military variety.
Threading the burnt cores onto needles would definitely not be my idea of fun. Though I imagine a needle full of them would resemble a string of beads. Come to think of it, as described those cores would make a mighty interesting necklace (and FWIW my wife thought so too).
Wikipedia has more info: https://en.wikipedia.org/wiki/Naval_Tactical_Data_System
The book When Computers Went to Sea: The Digitization of the United States Navy has a very detailed history.
https://www.tindie.com/products/kilpelaj/core-memory-shield-...
Erbium has found a use, in picogram quantities, to amplify optical signals in fibers directly from exposure to light. Terbium was once used for the green dots on TV screens, but is still used in a material that expands and contracts in response to magnetic fields. Uses for ytterbium are more obscure.
High-temperature superconductivity might be useful someday.
Does that sound "defensive" to everyone?
I don't know this area of engineering, so, to my ear, this could also plausibly be an almost admiring acknowledgement of someone else succeeding where you'd failed, combined (non-defensively) with confidence, because you had the strength or other superior merit to take it from them?
Various nationalism and other thinking, in different groups, at different times, are still largely a mystery to me. It seems relevant to group thinking we see today, which is still confusing (e.g., why is much of the thinking and dialogue around the two main US political parties doing what it's doing, and how is that representative/determining of what the broader population actually thinks).
Subs use them, high T and rad places still use them (Im told).
Don't forget "and a bunch of actual Nazi scientists just for good measure" https://en.wikipedia.org/wiki/Operation_Paperclip#Key_recrui...
Is this a term used commonly? It's referenced in the subtitle but no where in the article.
Doesn't the larger AC load current itself also saturate the core though, overpowering whatever the much weaker current does? Or is only DC current able to saturate it?