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…

Modded Server PSU Provides Plenty Of Current

April 19, 2026 by Zoe Skyforest 20 Comments

Most makers find themselves in need of a benchtop power supply at some point or another. Basic models can be had relatively cheaply, but as your current demands go higher, so does the price. [Danilo Larizza] has figured out an alternative solution—repurposing old server hardware to do the job instead.

The build is based around an HP Common Slot (CS) server power supply. They can be readily had for well under $50 if you know where to look. Even better, they can deliver over 50 amps at 12 volts, which happens to be a very useful voltage indeed. All you need to do is some minor mods.

A jumper on a couple of pins will get the power supply running, and with the addition of some terminals for your hook-up leads, you’re ready to go. As a hot-swappable single unit, the power supply is already outfitted with a ventilation fan to keep everything cool. If so desired, you can even make some further mods to bump output voltage a little ways past 13 or 14 volts if you’d like to use them for certain battery charging tasks.

Sure, you’re not getting a variable power supply, but if you need 12 volts and lots of it, this is a great way to go. We’ve featured similar builds before, too, turning ATX PC power supplies into useful benchtop tools.

Continue reading “Modded Server PSU Provides Plenty Of Current” →

Quick & Capable WiFi For Your Nice-Power Supply

May 31, 2024 by Arya Voronova 15 Comments

Rejoice, those of us who have purchased a Nice-Power lab PSU from an Eastern source. Yes, the name might sound like a re-brand of a generic product, maybe you will even see this exact PSU on a shelf at a physical store near you, under a more local brand name and with a fair markup. Nevermind the circumstances, the most important part is that [Georgi Dobrishinov] found a way to add an ESP8266 to the PSU by tapping its internal UART control interface, and wrote a web UI for all your Internet-of-Lab-PSUs needs, called the PowerLinkESP project.

All you need is a Wemos D1 development board, or any other ESP8266 board that has UART pins exposed and handles 5 V input. [Georgi] brings everything else, from pictures showing you where to plug it in and where to tap 5 V, to extensive instructions on how to compile and upload the code, using just the Arduino IDE. Oh, and he tops it off with STLs for a 3D printed case, lest your Wemos D1 board flop around inside.

With [Georgi]’s software, you can monitor your PSU with interactive charts for all readings, export charts in both PNG and CSV, and access a good few features. Your ESP8266’s network uplink is also highly configurable, from an STA mode for a static lab config, to an AP mode for any on-the-go monitoring from your phone, and it even switches between them automatically! The firmware makes your PSU all that more practical, to the point that if you’re about to build an interface for your PSU, you should pay attention to [Georgi]’s work.

Lab PSUs with WiFi integration are worth looking into, just check out our review of this one; smart features are so nice to have, we hackers straight up rewrite PSU firmware to get there if we have to. Oh, and if you ever feel like standardizing your work so that it can interface to a whole world of measurement equipment, look no further than SCPI, something that’s easier to add to your project than you might expect, even with as little as Python and a Pi.

Simple ATX Bench Power Supply Adds Variable Output

December 1, 2022 by Zoe Skyforest 24 Comments

A benchtop power supply is a key thing to have for any aspiring electronics hacker. While you can always buy one, plenty of us have old computer PSUs lying around that could do a fine job themselves. [Frugha] decided to whip up a neat 3D-printed design for converting any ATX PSU into a usable bench unit.

The design features banana plugs outputting +12V, -12V, +5V, and +3.3V, with all outputs appropriately fused for safety. There’s also a fused stepdown converter used to supply variable voltages as needed. Its original trimpot was replaced with a multi-turn pot for ease of control. To make everything work, a load resistor on the 5V circuit makes the power supply think it’s hooked up to a motherboard. It’s all wrapped up in a neat slant-sided 3D-printed case that fits onto the ATX power supply itself.

The result is a neat and tidy power supply built out of readily-available components. We particularly like the addition of the stepdown converter – most ATX-based projects don’t offer variable output, which can nonetheless come in handy.

We’ve seen some other great builds along these lines before, too. If you’ve been cooking up your own homebrew power supply, don’t hesitate to share it on the tipsline!

Rescue That Dead Xbox With An External PSU

December 1, 2022 by Jenny List 13 Comments

There is nothing worse than that sinking feeling as a computer or other device fails just after its warranty has expired. [Robotanv] had it with his Xbox Series S whose power supply failed, and was faced with either an online sourced PSU of uncertain provenance, or a hefty bill from Microsoft for a repair. He chose to do neither, opening up his console and replacing the broken PSU with a generic external model. See the video below the break.

The Xbox appears surprisingly well designed as a modular unit, so accessing and unplugging its PSU was quite easy. To his surprise he found that the connections were simply two wires, positive and negative lines for 12 V. The solution was to find a suitably beefy 12 V supply and wire it up, before continuing gaming.

Beyond that simple description lies a bit more. The original was a 160 W unit so he’s taken a gamble with a 120 W external brick. He’s monitoring its temperature carefully to make sure, but with his gaming it has not been a problem. Then there’s the board wiring, which he appears to have soldered to pads on the PCB. We might have tried to find something that fit the original spade connectors instead, but yet again it hasn’t caused him any problems. We’d be curious to see what has failed in the original PSU. Meanwhile we’re glad to see this Xbox ride again, it’s more than can be said for one belonging to a Hackaday colleague.

Continue reading “Rescue That Dead Xbox With An External PSU” →

Junk I Bought: My PSU Just Won’t Do

May 31, 2022 by Jenny List 98 Comments

I have an Acer monitor that I’ve owned for around 15 years, and thanks to my having paid extra at the time for the model sporting a DVI socket for HDMI compatibility it still finds a place as one of my desktop monitors. It has a power brick that supplies it with 1 2V at 4.5 A, and over the years this has developed an annoying whine. Something’s loose in the magnetics, and I really should replace it. So off to AliExpress I went, and dropped in an order for a 12 V, 5 A power brick.

It’s No Heavyweight

A PSU brick, marked as 12V 5A — So far so good…

These units are pretty standard, a box about 130 mm by 60 mm with an IEC socket at one end and a trailing cable at the other for the low voltage. I’ve had enough of them pass through my hands over the years to know what to expect, so I was dismayed to find when I received my PSU that it was suspiciously light. 86 g compared to the around 250 g I’d expect, so I began to smell a rat. Time for a teardown, and a descent into the world of small switch-mode mains power supplies.

Normally it should be easier to break into Fort Knox than to crack open a mains power supply, because for safety they are ultrasonic welded together. The few times I’ve done it have required some Dremel time and a bit of swearing, so when this case turned out to open fairly easily by levering with a screwdriver it was evident this wasn’t a high-quality item. Sure enough my suspicions were confirmed, for there inside was a much smaller board. It’s clear this isn’t a 5 A power supply, so just what have I received? Continue reading “Junk I Bought: My PSU Just Won’t Do” →

A Simple Linear Power Supply, Done Well

April 5, 2022 by Jenny List 45 Comments

When reaching for a power supply design it’s normal here in 2022 to reach for a switching design. They’re lightweight, very efficient, and often available off-the-shelf at reasonable prices. Their benefits are such that it’s become surprisingly rare to see a traditional linear power supply with a mains-frequency transformer and rectifier circuit, so [ElectroBoy]’s dual voltage PSU board for audio amplifiers is worth a second look.

This type of linear power supply has an extremely simple circuit consisting of a transformer, bridge rectifier, and capacitors. The transformer isolates and steps down the AC voltage, the rectifier turns it into a rough DC, and the capacitors filter the DC to remove as much AC ripple as possible. In an audio power supply the capacitors have the dual role of filtering and providing an impulse reservoir for the supply in the event of a peak in demand imposed by the music being played. Careful selection is vital, with in this case a toroidal mains transformer and good quality capacitors being chosen.

The choice between a linear power supply such as this one and a switching design for high quality audio is by no means clear-cut, and may be something we’ll consider in our Know Audio series. The desirable properties are low noise and that impulse reservoir we mentioned, and it’s probably fair to say that while both types of power supply can satisfy them. With the extra expense of a toroidal transformer a linear supply is unlikely to be the cheaper of the two, but we suspect the balance tips in its favour due to a good linear supply being the easier to design.