Crowdsourcing An Investigation Into Coil Whine

September 1, 2026 by Zoe Skyforest 31 Comments

If you’ve heard the high-pitched whine or buzz from an electronic device when a current-carrying inductor is vibrating, you’ll know how unpleasant it can be. It’s common in all kinds of equipment, but it’s become a particular annoyance of late in hardware like PC power supplies, GPUs, and cooling pumps. There is plenty of hearsay on the web about which parts whine and which don’t, and [Lowell Wood] wants to get to the bottom of it.

To track the issue, [Lowell] has put together the Coil Whine Database. It accepts user reports on hardware, regarding the level at which coil whine is present. A score of 0 is given to a part that is inaudible in a quiet room, with higher scores representing higher sound levels. A part scored at 2 is audible working at a desk with the computer under load; a part scored at 4 is audible even when the machine or device is at idle.

For now, the database is largely empty—[Lowell] has just opened submissions, adding a report on their own ROG Astral RTX 5080 card for good measure. If you want to submit a report on a unit, either silent or noisy, that’s simple enough—just fill in the coil whine report form. Over time, submissions will hopefully grow, and it will be easier to get a good idea of what equipment whines and what is likely to operate silently out of the box.

The database aims to present a guide to what parts whine, and how much, noting that any given population of devices tends to vary. To that end, any given device won’t be reported on publicly until it receives at least 5 reports. To counter bias, reports of silent parts will be weighted higher, since it’s unlikely that people happy with their quiet hardware will be rushing to research this issue or report it to a database. Relevant files to the project are available on GitHub for the curious.

This database could be a great boon to the brigade of PC builders out there who like their machines to be as silent as possible. If that sort of thing appeals to you, it’s probably time you started researching passive cooling as well…

How Volunteers Saved A Victorian-Era Pumping Station From Demolition

February 16, 2026 by Maya Posch 13 Comments

D-engine of the Claymills Pumping Station. (Credit: John M)

Although infrastructure like a 19th-century pumping station generally tends to be quietly decommissioned and demolished, sometimes you get enough people looking at such an object and wondering whether maybe it’d be worth preserving. Such was the case with the Claymills Pumping Station in Staffordshire, England. After starting operations in the late 19th century, the pumping station was in active use until 1971. In a recent documentary by the Claymills Pumping Station Trust, as the start of their YouTube channel, the derelict state of the station at the time is covered, as well as its long and arduous recovery since they acquired the site in 1993.

After its decommissioning, the station was eventually scheduled for demolition. Many parts had by that time been removed for display elsewhere, discarded, or outright stolen for the copper and brass. Of the four Woolf compounding rotative beam engines, units A and B had been shut down first and used for spare parts to keep the remaining units going. Along with groundwater intrusion and a decaying roof, it was in a sorry state after decades of neglect. Restoring it was a monumental task.

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How Hydraulic Ram Pumps Push Water Uphill With No External Power Input

October 2, 2025 by Zoe Skyforest 33 Comments

Imagine you have a natural stream running through a low-lying area on your farm. It’s a great source of fresh water, only you really need it to irrigate some crops sitting at a higher elevation. The area is quite remote from fixed utilities, complicating the problem.

Your first thought might be to grab a commercial off-the-shelf pump of some sort, along with a fancy solar power system to provide the necessary power to run it. But what if there were a type of pump that could do the job with no external power input at all? Enter the hydraulic ram pump.

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Oil-Based Sprengel Pump Really Sucks

September 17, 2025 by Tyler August 21 Comments

Have you heard of the Sprengel pump? It’s how they drew hard vacuum back before mechanical pumps were perfected — the first light bulbs had their vacuums drawn with Sprengel pumps, for example. It worked by using droplets of a particular liquid to catch air particles, and push them out a narrow tube, thereby slowly evacuating a chamber. The catch is that that liquid used to be mercury, which isn’t something many of us have on hand in kilogram quantities anymore. [Gabriel Wolffe] had the brainwave that one might substitute modern vacuum pump oil for mercury, and built a pump to test that idea.

Even better, unlike the last (mercury-based) Sprengel pump we saw, [Gabriel] set up his build so that no glassblowing is required. Yes, yes, scientific glassblowing used to be an essential skill taught in every technical college in the world. Nowadays, we’re glad to have a design that lets us solder brass fittings together. Technically you still have to cut an eyedropper, but that’s as complex as the glasswork gets. Being able to circulate oil with a plastic tube and peristaltic pump is great, too.

If you try it, you need to spring for vacuum pump oil. This type of pump is limited in the vacuum it can draw by the vapor pressure of the fluid in use, and just any oil won’t do. Most have vapor pressures far in excess of anything useful. In the old days, only mercury would cut it, but modern chemistry has come up with very stable oils that will do nearly as well.

How well? [Gabriel] isn’t sure; he bottomed out his gauge at 30 inches of Mercury (102 kPa). It may not be any lower than that, but it’s fair to say the pump draws a healthy vacuum without any unhealthy liquid metals. Enough to brew up some tubes, perhaps.

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Mining And Refining: Mine Dewatering

October 17, 2024 by Dan Maloney 9 Comments

From space, the most striking feature of our Pale Blue Dot is exactly what makes it blue: all that water. About three-quarters of the globe is covered with liquid water, and our atmosphere is a thick gaseous soup laden with water vapor. Almost everywhere you look there’s water, and even where there’s no obvious surface water, chances are good that more water than you could use in a lifetime lies just below your feet, and accessing it could be as easy as an afternoon’s work with a shovel.

And therein lies the rub for those who delve into the Earth’s depths for the minerals and other resources we need to function as a society — if you dig deep enough, water is going to become a problem. The Earth’s crust holds something like 44 million cubic kilometers of largely hidden water, and it doesn’t take much to release it from the geological structures holding it back and restricting its flow. One simple mineshaft chasing a coal seam or a shaft dug in the wrong place, and suddenly all the hard-won workings are nothing but flooded holes in the ground. Add to that the enormous open-pit mines dotting the surface of the planet that resemble nothing so much as empty lakes waiting to fill back up with water if given a chance, and the scale of the problem water presents to mining operations becomes clear.

Dewatering mines is a complex engineering problem, one that intersects and overlaps multiple fields of expertise. Geotechnical engineers work alongside mining engineers, hydrogeologists, and environmental engineers to devise cost-effective ways to control the flow of water into mines, redirect it when they can, and remove it when there’s no alternative.

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Junk Bin Build Lets You Test Fuel Injectors On The Cheap

July 30, 2024 by Dan Maloney 32 Comments

Fiddle around with cars long enough and you’ll realize two things: first, anything beyond the simplest repairs will probably require some kind of specialized tool, and second, those tools can be prohibitively expensive. That doesn’t mean you’re out of luck, though, especially if you’ve got scrap galore and a DIY spirit, as this junk bin fuel injector test stand ably demonstrates.

[Desert Rat Racer]’s test rig is designed to support four injectors at once and to test them under conditions as close as possible to what they’ll experience when installed. To that end, [Rat] mounted a junk intake manifold to a stand made from scrap wood and metal found by the side of the road. A pickle jar serves as a reservoir for the test fluid — he wisely used mineral spirits as a safer substitute for gasoline — and a scrap electric fuel pump pressurizes a junk fuel rail, which distributes fuel to the injectors under test.

For testing, the injectors are wired up to an electric injector tester, which is one of the few off-the-shelf components in the build. The fuel pump and injectors are powered by the 12 volt rail of a scrapped PC power supply. Just being able to watch the spray pattern is often enough to find a faulty injector, but in case a more quantitative test is indicated, each injector is positioned over a cheap glass cylinder to catch the test fluid, and scraps of a tape measure are used to measure the depth of the collected fluid. No fancy — and expensive — graduated cylinders required.

While we truly respect the hackiness of [Desert Rat Racer]’s build, the concept of avoiding buying tactical tools is foreign to us. We understand the logic of not dropping a ton on a single-use tool, but where’s the fancy blow-molded plastic case?

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A Compact Electrohydrodynamic Pump Using Copper And TPU

June 9, 2024 by Maya Posch 21 Comments

Electrohydrodynamics (EHD) involves the dynamics of electrically charged fluids, which effectively means making fluids move using nothing but electric fields, making it an attractive idea for creating a pump out of. This is the topic of a 2023 paper by [Michael Smith] and colleagues in Science, titled “Fiber pumps for wearable fluidic systems”. The ‘fiber pumps’ as they call the EHD pumps in this study are manufactured by twisting two helical, 80 µm thick copper electrodes around a central mandrel, along with TPU (thermoplastic polyurethane) before applying heat. This creates a tube where the two continuous electrodes are in contact with any fluids inside the tube.

For the fluid a dielectric fluid is required to create the ions, which was 3M Novec 7100, a methoxy-fluorocarbon. Because of the used voltage of 8 kV, a high electrical breakdown of the fluid is required. After ionization the required current is relatively low, with power usage reported as 0.9 W/m, with one meter of this pump generating a pressure of up to 100 kilopascals and a flowrate of 55 mL/minute. One major limitation is still that after 6 days of continuous pumping, the copper electrodes are rendered inert due to deposits, requiring the entire system to be rinsed. Among the applications the researchers see artificial muscles and flexible tubing in clothing to cool, heat and provide sensory feedback in VR applications.

While the lack of moving parts as with traditional pumps is nice, the limitations are still pretty severe. What is however interesting about this manufacturing method is that it is available to just about any hobbyist who happens to have some copper wiring, TPU filament and something that could serve as a mandrel lying around.

Thanks to [Aaron Eiche] for the tip.