Volt nuts get ready....  - Page 1
Forum section: electronics / general

author: Cyclotron
author_rank: Unknown
timestamp: August 21, 2025, 02:16:36 am
content: I find myself fascinated by time and volts, and as a nut, I'm often drawn to news, though few and far between, about advancements in the measurement of either.Science has been about using quantum systems to make measurements with accuracy and concurrences not previously seen.https://phys.org/news/2025-08-quantum-device-amperes-volts-ohms.htmlSourced from this paper:https://www.nature.com/articles/s41928-025-01421-28.5 digits, meet quantum.

author: Cyclotron
author_rank: Unknown
timestamp: August 21, 2025, 02:19:45 am
content: Maybe a less paywalled copy of the paper?https://arxiv.org/html/2308.00200v2Related NIST linkhttps://www.nist.gov/news-events/news/2025/08/all-one-nist-develops-single-device-realize-electrical-standards

author: LaserSteve
author_rank: Super Contributor
timestamp: August 21, 2025, 02:17:17 pm
content: Even with therabidavid extreme dedication of a typical Voltnut, I'm not so sure a homemade dilution refrigerator is in the cards to exploit this device in its present form.Still, it is "cool" that NIST still leads the world in standards development. My tax Dollars at work.This, However, is more practical:https://www.nist.gov/sri/standard-reference-instruments/sri-6000-series-programmable-josephson-voltage-standard-pjvsCut Sheet for the above is attached.Steve

author: BarrowBoy
author_rank: Contributor
timestamp: August 21, 2025, 05:52:27 pm
content: Wow, that is amazing. One device that can measure 3 different SI units. That seems a huge leap forward. It's a shame your both in the US, I'm looking for a Volt Nut based in Sydney who has a day to spare next week to attend the Australian and New Zealand Metrology conference where our version of NIST (NATA) and our NMI meet to discuss Metrology matters. I'm about to offer a free ticket if someone is keen enough. A couple of sessions will be live streamed.https://metrology.asn.au/events/msa-conference-sydney-aus-25-28-august-2025/Have a great day folks.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 21, 2025, 05:56:54 pm
content: QuoteOh yes, because a "quantum device" is a practical system. Got it.

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 06:00:43 pm
content: Quote from: SiliconWizard on August 21, 2025, 05:56:54 pmConsult a good dictionary about the difference between "practical", "practicable", and affordable by a hobbyist in his basement lab.Quantum effects are real--live with it.The NIST will sell you this equipment, but I didn't inquire about price since my basement lab is too crowded.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 21, 2025, 06:16:15 pm
content: Quote from: TimFox on August 21, 2025, 06:00:43 pmYou keep bringing up this point.Yes, quantum effects are real. (At least I suppose they are: I'm relying on the word of pointy-headed scientists here, since I hardly understand a single concept in this area.)But you know what?Those effects are totally irrelevant to the vast majority of us.Even those of us who dabble in electronics.Sure, if you'redesigning semiconductors, then you may need to bone up on quantum physics.But if you're putting together a circuit from commercially-available parts, then quantum physics has no application to your work. Zero.I challenge you to come up with a viable example where one would need to know quantum stuff that doesn't involve the creation of semiconductors.

author: Echo88
author_rank: Frequent Contributor
timestamp: August 21, 2025, 06:25:30 pm
content: Calibrating calibrators and voltage standards of the highest accuracy is one task of a quantum based standard like the JJA/PJVS and for resistance standards its a comparison against a quantum hall standard, which might be done by this device when improved to the required ranges.I challenge you to not post for a few days to get your 10 posts/day yapping quota down Analog Kid.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 21, 2025, 06:34:46 pm
content: Quote from: Echo88 on August 21, 2025, 06:25:30 pmInteresting devices: I didn't know about all that Josephson stuff,described here.However, even if those instruments are "quantum-accurate" as they say, does that mean that the user must even understand anything about quantum physics in order to use them? Can't they use them as they'd use any ordinary voltage reference? Just much more accurate.Wouldn't that be like requiring drivers to understand drive-control electronics in order to drive an EV?

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 06:59:55 pm
content: Quote from: Analog Kid on August 21, 2025, 06:16:15 pmGet with the times: 2025 is the International Year of Quantum Science and Technology.A primer for schoolchildren:https://www.nist.gov/physics/international-year-quantumAs to your challenge, a good chunk of my professional career was in Magnetic Resonance Imaging, which relies on macroscopic effects of quantized magnetic moment from the spin of elementary particles, with no semiconductors in sight. The 2024 market for MRI machines is estimated at $7,100,000,000.https://www.grandviewresearch.com/industry-analysis/magnetic-resonance-imaging-market

author: Analog Kid
author_rank: Super Contributor
timestamp: August 21, 2025, 07:11:24 pm
content: Yes, MRI.But again: does theuserof that device (the radiologist I'm assuming here) need to know anything about quantum physics in order to use it?

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 07:16:33 pm
content: Yes. The actual signal that is reconstructed into an image depends greatly on the physical situation, including quantum effects, especially "decay time constants" that are chemically dependent.For example: due to the "chemical shift" in frequency, an image of a kidney can show a non-physical effect where the cap of fat on the top of the kidney is displaced from the organ itself.If that were a real effect, it would be medically significant.Radiologists, the medical doctors who interpret the images, learn elementary physical quantum effects in order to understand the "gray scale" shown in the final images.Various settings on the machines ("protocols") will change the gray scale, and can be exploited in order to visualize the important physical parameters of the patient's anatomy.Historical anecdote: a lady sitting next to President Calvin Coolidge (known for his silence) at a dinner party said unto him: "Mr. Coolidge, I bet my friend that I could get more than two words out of you." "You lose" was the reply.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 21, 2025, 07:33:39 pm
content: Quote from: TimFox on August 21, 2025, 07:16:33 pmI don't know what, if anything, that has to do with the present discussion (unless you're telling me "you lose!"), but it was worth a chuckle nonetheless.

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 07:36:11 pm
content: Quote from: Analog Kid on August 21, 2025, 07:33:39 pmThat's right: you demanded an example not in semiconductor design and I provided one.

author: LaserSteve
author_rank: Super Contributor
timestamp: August 21, 2025, 07:36:36 pm
content: CT Machines have similar problems related to tissue density (Radiodensity) and some quantum effects, such as diffraction and scattering off implanted metals. Hence the use of the Houndsfield scale.You can safely assume they are taught how to exploit what happens, and how to work around some of the more negative issues.The softer X-Rays have to be filtered out, especially the ones that will not make it through the patient but will add to their overall dose. The filters are aluminum, copper and nylon for selective quantum adsorption in the machines I worked on. The X-ray tube produces a broad Spectrum, and that spectrum shifts to more energetic X-rays with greater applied Voltage.I spent a lot of time learning how to calibrate CT machines and evaluate detector linearity for a former employer.Over time the scintillators in the detector can degrade from dosage, reducing dynamic range.The Radiologist has sliders that determine what parts of the data appear in the image, because reducing a twelve-bit data set to a few shades visible on the LCD screen is both science and art. To standardize across machines, the Houndsfield scale is used.Most Radiologists prefer to turn off the synthetic color and read the results in greyscale. So the scale runs from -1000 thru zero to plus 1000, and you have to fit that to 64-255 visible shades of LCD. Most radiologists hung on to specialized B&W medical CRTS for displays as long as possible, for a reason.Iodine compounds and other contrast agents are injected into the bloodstream or swallowed are used to evaluate organ function. Couple that with dual methods like CT/PET and you really need to know some serious physics to get things right for the patient.So yes, they are trained intensively in how to set the scales to visualize a given tissue and what the contrast agents and tracers do. The chemicals injected have half lives in both radiochemistry and dilution in the body fluids.So the Radiologist trains the technician running the machine to set the Tube Current, Tube Voltage, Scan Rate, and Patient motion to achieve a given result and to minimize dosage.If the image quality is degrading, the Radiologist and the Biomedical Engineer have to agree on a course of action. Despite wonderful automation and software, much depends on how well the Biomed aligns and tunes the machine. Placing the test phantom a little off center during calibration can make life miserable for the Radiologist and Imaging Technician.MRI is sort of a complementary technique to CT, so knowing what technique images what requires serious knowledge and training. PET and SPEC imaging even more so.Steve

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 07:48:23 pm
content: False color in radiography:We built x-ray machines, including CAT scanners, for medical and industrial purposes, during my career.The industrial users tended to prefer false-color rendering, since they were usually looking for flaws in the object (e.g., cracks).The medical users stayed with gray-scale, since they thought the false-color images tended to give inaccurate results.The Hounsfield units were nominally calibrated for 0 = water, and -1000 = air. Bone ranged around +1000, depending on density.That covered the range of biological materials, but high-density metal implants could send the image off-scale locally in the reconstruction.The industrial users were used to a positive-definite scale for CT, that could be calibrated to material density (for a homogeneous material).Some users, unfamiliar with the technology, wanted to use Photoshop to process the images, but skilled users learned how to "window" the image, setting window width and level to visualize the object.I got out of medical imaging about the time that the good medical-grade CRTs were replaced by good flat-panel displays (both very expensive); the first time I saw such a flat-panel at RSNA, I thought I was looking at an x-ray plate on a light box. At that time, I believe the FDA-certified displays went for something like $20k.

author: Cyclotron
author_rank: Unknown
timestamp: August 21, 2025, 08:36:22 pm
content: Although we have not been able to completely align classical vs. quantum physics I believe that the general consensus is that we will and that we are getting closer.Regardless of that, this particular forum would likely have the most generalized interactions at the boundaries between the classical and quantum given so much of it is related, fields, effects, and states.How things behave in P-N Junctions and how various things interact "near" each other.I would agree that no physics degree, classical or quantum is required. But I'd say that a strong knowledge of the theories and reasons things "work" the way they do is part of why many of us do this and why it goes along with being good at doing it.

author: Cyclotron
author_rank: Unknown
timestamp: August 21, 2025, 08:41:35 pm
content: Quote from: BarrowBoy on August 21, 2025, 05:52:27 pmI travel a lot but have no current plans to be on in that part of the world this year. I'd love to go to the sessions.I just finished my first read of this:https://www.amazon.com/Introduction-Timekeeping-Transfer-Measurement-Technology/dp/3031307798

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 08:47:35 pm
content: Quote from: Cyclotron on August 21, 2025, 08:36:22 pmI agree that expertise in quantum physics is not required for most electronic work, but a basic knowledge is useful.An important "alignment" between classical and quantum physics, as stated in the "Copenhagen interpretation", is Bohr's "Correspondence Principle", which states that quantum results approach classical results in the limit of large quantum number or macroscopic systems. Modern physics does admit to exceptions to this rule, however.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 21, 2025, 08:55:52 pm
content: Quote from: TimFox on August 21, 2025, 07:36:11 pmYes you did.So MRI users need some basic knowledge of quantum physics. I stand (sit, actually) enlightened.Any other examples where theuser(not the designer) needs to know something about this in order to use the device or system?

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2025, 08:57:15 pm
content: Quote from: Analog Kid on August 21, 2025, 08:55:52 pmMost of chemistry, as done by chemists, including spectroscopy.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 21, 2025, 11:29:07 pm
content: Quote from: Analog Kid on August 21, 2025, 06:16:15 pmWell is it OK to be using semi-conductors? Anyone using junction detectors be they Silicon, InSb, HgCdTe or various other detectors is using quantum effects which determine the cut-off frequency. Use a laser? Heavily dependent on quantum effects. How about superconductors?Now using these things doesn't require deep understanding of quantum stuff. You can do bulk approximations to get practical answers. So in one sense you are right. Just like the people listening to an MP3 player don't need to understand coding theory, microcontroller programming or even ohms law. But they heavily depend on all of those things in their daily lives.

author: John Coloccia
author_rank: Super Contributor
timestamp: August 22, 2025, 04:22:17 am
content: Quantum physics/devices/experiments/etc. have been a thing for well over 100 years. Also, the Earth is not flat.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 22, 2025, 04:29:24 am
content: Quote from: John Coloccia on August 22, 2025, 04:22:17 amI think you, like a lot of other folks here, are totally missing my point.I'm not denying that quantum physics is a real thing.All I'm saying is that even here in electronics, most of us--I'm guessing the vast majority of those who post here on this site--have no need of understanding it in our work.Tim Fox pointed out two examples where someone does need at least a basic understanding of Q.P: using an MRI machine and chemistry.For someone like me, a hobbyist, so far as I can tell no knowledge whatsoever of quantum physics will ever be needed in designing and building my projects. And I'm willing to bet this applies to 80-90% of the people who frequent this forum.Those who design and manufacture semiconductors need to know about this stuff, sure.Doyouneed to know about quantum physics in your line of work?Notice I didn't ask if you were curious about or interested in it; I'm asking if it's essential to your line of work.My guess©™ is no.

author: John Coloccia
author_rank: Super Contributor
timestamp: August 22, 2025, 04:47:56 am
content: Quote from: Analog Kid on August 22, 2025, 04:29:24 amToday, no. In previous lives, maybe. It's a low bar that we should only discuss the least common denominator of everyone's work It would be more interesting if you read the paper and had some technical criticisms.

author: Analog Kid
author_rank: Super Contributor
timestamp: August 22, 2025, 05:11:03 am
content: Quote from: John Coloccia on August 22, 2025, 04:47:56 amI'm sure it would be more interesting, but it's just too far over my head (the quantum-physics stuff), so no technical criticisms from this quarter.Not at all ashamed to admit that here.

author: Cyclotron
author_rank: Unknown
timestamp: October 08, 2025, 06:14:46 pm
content: Quote from: MathHasYou on October 08, 2025, 05:36:47 pmAs a knowledge consumer and voracious one at that, I long didn't understand why people were willing to be ignorant of how things work. As I've aged, I realized that the switch for such desire is on in some and off in others. Assertions about the need for knowledge and the implications of its usefulness based on being "required" to know it seem like a question that would make sense to the latter individual.Why study any arts if you're a plumber or dig ditches for a living? There are a whole host of things I "know" that are not related to my job role. However, I can assure you that they do inform me, influencing my conversations, decisions, judgment, and considerations. The patterns of the world reappear everywhere, and a diversity of knowledge allows you to recognize them and find intuition much more rapidly. Just as arecent study showing how the patterns in fractal chaosmay have no implications for my job today, I will likely have conversations that relate to it with like minded people and create work related bonds around the shared knowledge.All of the above aside. In the hobby of EE, if you intend to be productive and effective, you should know why and how things work to be able to peek into the mind of the creator.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 08, 2025, 06:25:37 pm
content: In quite some cases quantum mechanics at some level is needed to design and fully understand the function of new semiconductor devices. However for the final use of such systems the details are no longer needed and a simpler description / model can be used that no longer looks like quantum mechanics.Lasers are an example that needs quantum mechanics to understand, but can later be used like a normal light source in optics.The full quantum standard from the starting article is still for from practical for daily use. It still needs to low temperature to make it work. So currently more a national lab thing. For every day use it may change with a working JJA or superconducting DCC at liquid nitrogen temperature.

author: Electrodynamic
author_rank: Regular Contributor
timestamp: October 08, 2025, 06:37:41 pm
content: CyclotronQuoteSo if I am reading this correctly they built a nano-scale, substrate based microwave induced charge pump?.Similar to a positive displacement pump for electron pairs using each microwave pulse as the piston. Of course, it would be far more accurate than most other devices measuring the bulk or averaged flow versus individual particles.It seems pretty common sense to me. I wonder why they didn't figure this out a decade ago?.Much more impressive would be to apply this principal to nano or meta-material power generation. Integrate something like the Casimir effect into the process to replace the microwave energy. Now were getting close to a process proposed by Maxwell, his supposed demon. I imagine someone will eventually figure it out a hundred years from now.

author: Cyclotron
author_rank: Unknown
timestamp: October 08, 2025, 07:03:59 pm
content: Quote from: Electrodynamic on October 08, 2025, 06:37:41 pmThat's a fantastic question. I really hadn't thought about that aspect. Maybe, and I don't know, the available precision was "good enough," but now that we are approaching the sub-nanometer for circuits or other aspects of metrology, we need this? Maybe it's just science for science? I'm jaded enough to think that most modern research is driven by some financial gain outcome.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 08, 2025, 08:40:24 pm
content: Counting electrons in the so called electron turn-styles is not a new idea. The tricky part here is making shure to really pump an electron every time and not more. A difficulty is that the current is rather small. So one may get ppm accurate current, but in the nA range. So the link to normal metrology is a bit tricky.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 08, 2025, 10:59:42 pm
content: Quote from: Analog Kid on August 22, 2025, 04:29:24 amThere are few lines of work where a good understanding of everything that you are doing is necessary. To keep this out of the scary to you quantum realm take welding. People spend their entire careers welding without a deep understanding of the material science involved. Alloys in both the material and the filler. Chemistry in the fluxes and/or inerting gases. Problems with heating rate and duration. If your career involves welding the same gussets onto the same frame day in and day out none of that matters. You just take the rod that was called for, the welder parameters you were given and do the weld the way you were trained. But a really good welder can deal with a great many more situations and make a lot more money.What several of us are saying is that there are many applications of quantum mechanics that have an impact on macro scale behavior. You are right, you don't absolutely have to understand it if you are utilizing the macro scale behavior. But if you don't you will be limited, sometimes making mistakes of ignorance, and other times missing opportunities for better performance or better understanding of the quality of your measurements.Whether you need this understanding is a you question. Not a general case.

author: Electrodynamic
author_rank: Regular Contributor
timestamp: October 09, 2025, 03:44:41 pm
content: CatalinawowQuoteI agree and arc weld/TIG/fabricate on a weekly basis.However this has little to do with industry and efficiency. In industry the majority of welding is all done by machines having superior quality and speed. In the future most welding will probably be laser or induction based not arc discharges.So we can see the progression of technology where we are acting on materials down to smaller and smaller scales. In fact, I was researching one very exotic technology which could possibly liquefy a metal without the generation of large amounts of heat. Let that sink in. Here we are literally talking about acting on a material at the atomic or quantum scale.Think of it this way, our arc and heat is just a convenient way to excite the atoms of the metal so they can move around easier. Heat is a measure of how fast the atoms are jiggling relating to mobility. However there may be other ways to make our metal atoms jiggle faster outside the context of heat. In effect, welding at room temperature?.