Українською
  In English
Feed aggregator
iFixit (@iFixit@mastodon.social)
![]() | submitted by /u/Linker3000 [link] [comments] |
NIH funds research to develop a game-changing HIV diagnostic tool
Taking apart a wall wart

Although in general I strive to cover a diversity of topics here in the blog, regular readers may have noticed that some amount of chronological theme-grouping still goes on. A few years back, for example, I wrote a fair bit about building PCs, both conceptually and in un-teardown (i.e., hands-on assembly) fashion. After that, there was a cluster of posts having to do with various still and video photography topics. And last year (extending into early this year) I talked a lot about lithium-based batteries, both in an absolute sense and relative to sealed lead-acid forebears, as well as the equipment containing them (and recharging them, i.e., solar cells).
Well, fair warning: this post is the kickoff of another common-topic cluster, having to do with audio. This isn’t a subject I’ve ignored to this point, mind you; consider just in recent times, for example, my posts on ambient noise suppression, interconnect schemes, lossy compression algorithms and listening gear (portable, too), microphones (plus on-PCB ones, tearing them down, and boosting their outputs) and exotic headphones, among others. But even more recently, I’ve obtained some “Chi-Fi” (i.e., built and often also directly sold by China-based suppliers) audio equipment—class D amplifiers and the like—along with audio gear from a US-based company that also does Stateside assembly, yet still effectively competes in the market.
What is a wall wart?More on all of that in posts to come through the remainder of this year, likely also extending into the next. For now: what does all of this have to do with a wall wart? And what is a wall wart, for those of you not already familiar with the term? Here’s Wikipedia’s take on the topic:
An AC adapter or AC/DC adapter (also called a wall charger, power adapter, power brick, or wall wart) is a type of external power supply, often enclosed in a case similar to an AC plug. AC adapters deliver electric power to devices that lack internal components to draw voltage and power from mains power themselves. The internal circuitry of an external power supply is often very similar to the design that would be used for a built-in or internal supply.
Today’s victim arrived via a Micca PB42X powered speaker set, purchased from an eBay seller:
They’d previously belonged to her son, who according to her never used them (more on that later), so she was offloading them to make some money. Problem was, although she’d sent me photos beforehand of the right speaker (fed by an RCA input connector set and containing the class D amplifier circuitry for both speakers; a conventional strand of speaker wire connects its output to its left-speaker sibling’s input) powered up, complete with a glowing red back panel LED, no AC adapter was accompanying it when it arrived at my front door.
After I messaged her, she sent me the “wall wart” you’ll see today, which not only was best-case underpowered compared to what it should have been—12V@500mA versus 18V@2A—but didn’t even work, outputting less than 200mV, sometimes measuring positive and other times negative voltage (in retrospect, I wish I would have also checked for any AC output voltage evidence before dissecting it):
She eventually agreed to provide a partial refund to cover my replacement-PSU cost, leaving me with a “dead” wall wart suitable only for the landfill. Although…I realized right before tossing it that I’d never actually taken one apart before. And this’d also give me a chance to test out the hypothesis of a hilariously narrated (watch it and listen for yourself) video I’d previously come across, proposing a method for getting inside equipment with an ultrasonic-welded enclosure:
Best video ever, right? The topic was of great interest, as I often came across such-sealed gear and my historical techniques for getting inside (a hacksaw, for example) also threatened to inadvertently mangle whatever was inside.
I didn’t have the suggested wallpaper knife in my possession; instead, I got a paint scraper with a sharp edge and hammer-compatible other end:
And in the following overview shots, with the wall wart as-usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes, you’ll notice (among other things) the ultrasonic welded joint around the circumference, to which I applied my pounding attention:
Complete with a closeup of the (in)famous Prop. 65 sticker…
How’d it work out? Well…I got inside, as you’ll see, but the break along the joint wasn’t exactly clean. I won’t be putting this wall wart back together again, not that I’d want to try in this case:
Maybe next time I’ll use a more lightweight hammer, and/or with wield it with a lighter touch
Anyhoo, with the damage done, the front portion of the enclosure lifts off straightaway:
Two things baffle me about the interior of the front case piece:
- What’s the point of the two glue dabs, which aren’t location-relevant to anything inside?
- And what if any functional use does that extra diagonal plastic piece serve?
That all said, this is what we’re most interested in, right?
The insides similarly lifted right out of the remaining piece(s) of the enclosure:
If you hadn’t already noticed, the heftier front of the case had survived its encounter with the paint scraper and sledge intact. The smaller back portion…not so much:
Here’s an overview of the now-exposed back of the wall wart’s guts. The transformer, which I’m sure you already noticed before, dominates the landscape:
Now continuing (and finishing) the rotation in 90° increments:
Let’s take a closer look at that PCB hanging off the bottom:
I am, as reader feedback regularly reminds me, not an analog or power electronics expert by any means, but what I believe we’re looking at here is visual evidence of a very rudimentary form of AC-to-DC conversion, the four-diode bridge rectifier:
A diode bridge is a bridge rectifier circuit of four diodes that is used in the process of converting alternating current (AC) from the input terminals to direct current (DC, i.e. fixed polarity) on the output terminals. Its function is to convert the negative voltage portions of the AC waveform to positive voltage, after which a low-pass filter can be used to smooth the result into DC.
When used in its most common application, for conversion of an alternating-current (AC) input into a direct-current (DC) output, it is known as a bridge rectifier. A bridge rectifier provides full-wave rectification from a two-wire AC input, resulting in lower cost and weight as compared to a rectifier with a three-wire input from a transformer with a center-tapped secondary winding.
The low-pass filter mentioned in the definition is, of course, the capacitor on the PCB. And re the diodes, the manufacturer (presumably in aspiring to squeeze as much profit as possible out of the design) didn’t even bother going the (presumably more costly) integration route:
Prior to the availability of integrated circuits, a bridge rectifier was constructed from separate diodes. Since about 1950, a single four-terminal component containing the four diodes connected in a bridge configuration has been available and is now available with various voltage and current ratings.
Ironically, in looking back at Wikipedia’s “wall wart” page post-teardown, shortly before I began writing, I happened to notice this exact same approach showcased in one of the photos there:
A disassembled AC adapter showing a simple, unregulated linear DC supply circuit: a transformer, four diodes in a bridge rectifier, and a single electrolytic capacitor to smooth the waveform.
And it’s also documented in an interesting Reddit thread I found, which starts out this way:
Do inexpensive 12v wall warts usually use a transformer to step mains to about 12vac then bridge rectify and regulate to 12vdc?
Or
Do they use some minimal 1:1 transformer for isolation, rectify to dc then use a buck converter to drop to 12v?
Or some other standard clever design?
Look again at the PCB, though, specifically at the markings, and you might notice something curious. Let me move a couple of diodes out of the way to emphasize what I’m talking about:
Capacitor C5, the big one for output filtering, is obviously present. But why are there also markings for capacitors C1-C4 alongside the diodes…and why are they missing? The clue, I’ll suggest, appears in the last bit of Wikipedia’s diode bridge introductory section:
Diodes are also used in bridge topologies along with capacitors as voltage multipliers.
Once again to save cost, I think the manufacturer of this wall wart developed a PCB that could do double-duty. Populated solely with diodes, it (requoting Reddit) “uses a transformer to step mains to about 12vac then bridge rectify and regulate to 12vdc.” And for other wall wart product proliferations with other output DC voltages, you’ll find a mix of both diodes and capacitors soldered onto that same PCB.
Again, as I said before, I’m not an analog or power electronics expert by any means. So, at this point I’ll turn the microphone over to you for your thoughts in the comments. Am I at least in the ballpark with my theory (can you tell that MLB spring training just began as I’m writing this)? Or have I struck out swinging? And what else about this design did you find interesting?
—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.
Related Content
- Wall wart + battery = small UPS: Good idea or not?
- When reliability hangs by a “wall wart” thread
- USB bus-powered devices put an end to Wall Warts
- Those AC/DC modules: my, how you have shrunk!
- Sorting out USB-C power supplies: Specification deceptions and confusing implementations
The post Taking apart a wall wart appeared first on EDN.
Accidentaly bought more resistors than intended....
![]() | So I sort of bought all the resistors here by ordering 3 times and forgetting about the first 2 times. Atleast they are not all the same value. Altough i bought double the sets on 2w. Atleast i wont need too be buying resistors anytime soon. [link] [comments] |
PSA: Many VL6180x boards sold actually have VL6180 installed
![]() | So I wanted a nice and small proximity sensor module for my gesture-driven lights switch project, and found this nice device from ST: VL6180X proximity and ambient light sensor. There are newer sensors in VL53* family, but they lack ambient light part which is nice to have for a smart home device. I've purchased a couple of test modules from Amazon (https://www.amazon.com/vl6180x/s?k=vl6180x) and shortly found that ALS (light) sensor produces garbage output no matter which software library is used. After many hours of debugging and online search I've found out the reason: many modules sold on Amazon, AliExpress, etc, marked as VL6180X are actually VL6180. Which is exactly the same device in terms of pinout, software interface, etc - but lacks the ALS sensor. The visual difference is prominent - VL6180X does have third large optical window in the center (which is the ALS sensor), while VL6180 does not. However, many many vendors sell cheaper VL6180 as VL6180X, as shown on the picture and on half of the modules on the Amazon link above. So if you also want a proximity/ambient light sensor - look carefully at what you buy. [link] [comments] |
Strengthening Our Analytical Business to Solve Social Issues with Our Core Technologies
Hitachi High-Tech Corporation (“Hitachi High-Tech”) is strengthening its analytical business through integrating and jointly operating its Hitachi High-Tech Analytical Science Ltd. (“Hitachi High-Tech Analytical Science”) and Hitachi High-Tech Science Corporation (“Hitachi High-Tech Science”) businesses. As of April 1, 2025, Hitachi High-Tech Science will become Hitachi High-Tech Analysis Corporation as part of this re-structure.
By integrating the core technologies of both companies, we will be better equipped to address the increasingly complex processes involved in developing, manufacturing, and inspecting materials that our customers encounter. Bringing together X-ray fluorescence (XRF), optical emission spectroscopy (OES), laser-induced breakdown spectroscopy (LIBS), thermal analysis (TA), liquid chromatography and spectrophotometers from Hitachi High-Tech Analytical Science and Hitachi High-Tech Science will facilitate the development of new, innovative solutions.
Initiatives to create a safe and secure society, and reducing environmental impact are becoming increasingly important across a wide range of business fields including healthcare, semiconductors and electronic components, and batteries. The analytical division and beam technology division, which includes electron microscopes, are key to supporting Hitachi High-Tech Group’s Core Technology Solutions business. The Core Technology Solutions division leverages its expertise in Observation, Measurement, and Analysis to offer specialized solutions for measurement and inspection. These solutions support R&D, manufacturing, and quality control processes, helping to address both customer and societal challenges.
Whilst manufacturing processes are becoming more complex, waste reduction, circular economy, and preservation of raw materials are key to a more sustainable, global industry.
Hitachi High-Tech Group will use the “Power of Knowledge” it possesses to know accurately and leveraging deep understandings the genuine issues of society and customers, and we will contribute to create a sustainable society by solving these issues.
The post Strengthening Our Analytical Business to Solve Social Issues with Our Core Technologies appeared first on ELE Times.
Will Intel’s rush to shed non-core assets benefit potential buyers?

Intel, long known for its acquisition misadventures, has finally reached a reality check. Its new CEO, Lip-Bu Tan, has announced spinning off the company’s non-core businesses to focus on core operations: CPU design and contract chip manufacturing. “These parts of Intel are no longer central to its future,” he said during his keynote at the Intel Vision conference in Las Vegas, Nevada.
It’s important to note that Intel has already been on this path since the final days of former CEO Pat Gelsinger. The Santa Clara, California-based semiconductor firm has already spun off FPGA maker Altera. Even before Gelsinger took charge of the top job at Intel in February 2021, the company had sold its NAND memory business to SK hynix for $8.85 billion in 2020.
Tan didn’t indicate whether Intel will divest or sell its non-core businesses. Source: Intel
The company also turned Intel Capital into a standalone investment fund early this year before Tan took the CEO job. While Intel will remain an anchor investor, the fund will help the company to reduce costs and streamline operations.
So, what does this mean when Tan vows to shed the company’s non-core businesses? Apparently, Intel will pursue this endeavor more aggressively now to focus its CPUs on artificial intelligence (AI) and data center applications, along with what Tan calls a Software 2.0 strategy. But will Intel’s rush to shed non-core assets lower their market value? Or will Intel divest these units instead of seeking buyouts? Time will tell.
Intel’s non-core businesses
Now let’s discuss Intel’s non-core businesses. Start with Mobileye, a developer of automotive driver-assist systems, which was listed on Nasdaq in 2022. Though Intel has denied the plan to divest a majority stake in Mobileye in the past, it will now be one of the easiest targets for Intel to handle.
Intel’s networking division could also be up for grabs. However, many industry watchers consider Intel’s Network and Edge (NEX) group a core business of Intel. It focuses on edge computing, networking, and AI solutions while developing modified versions of consumer and data center CPUs for telecom companies and similar entities.
It’s worth noting that Altera and Mobileye are worth approximately $17 billion to 20 billion. Intel can generate a huge amount of cash from those two entities, which, in turn, will bring financial stability to this once-mighty semiconductor outfit now attempting to reclaim its past glory.
Still, the elephant in the room is not the non-core assets but whether Intel will remain whole or split up its CPU and contract manufacturing businesses. At the same time, however, Intel’s decision to shed non-core assets will bring much-needed stability during the turnaround that Tan envisions for this chip industry pioneer.
Related Content
- Who will get Altera in 2025
- We Really Need to Talk about Mobileye
- Intel More Likely to Divest Units Than Seek Buyout
- Intel’s Embarrassment of Riches: Advanced Packaging
- How will Intel’s purchase of Altera affect embedded space?
The post Will Intel’s rush to shed non-core assets benefit potential buyers? appeared first on EDN.
Casela launches 16-channel External Laser Source platform
Rohde & Schwarz presents comprehensive R&S ELEKTRA portfolio for reproducible, standard-compliant EMC measurements
Rohde & Schwarz continues to develop its R&S ELEKTRA EMC test software by adding new measurement methods, adapting it to new standards and ensuring that users can carry out measurement tasks even more efficiently. R&S ELEKTRA now supports all current EMC standards in the commercial, automotive, wireless, military and aerospace sectors. The software provides interactive, partially and fully automated solutions for EMC measurements during development and for fully automated standard-compliant certification measurements.
R&S ELEKTRA from Rohde & Schwarz, the market leader in EMC test and measurement, is a comprehensive EMC test software family that is ideally suited to the powerful Rohde & Schwarz line of EMC test instruments and signal and spectrum analyzers. The solution supports all current standard-compliant emission, radiated and conducted EMS measurements, including EMS tests in reverberation chambers (RVC), the use of AWGN interference signals and the simultaneous use of multiple interference signals. Development departments and EMC test labs can use this software to ensure their test instruments achieve peak performance and to make their test processes more efficient through automation. This saves resources, time and therefore money.
Efficient user interface and hardware usage save time and costs
R&S ELEKTRA test software automates EMC tests and controls the entire EMC system. The user interface provides access to all the important functions for the test setup at a single level. An extensive library of preset measurements and standard-compliant test setups and test sequences can also be accessed directly using a keyword search function, making test configuration much simpler. The first measurement takes only a few minutes to set up. R&S ELEKTRA makes optimum use of the computer’s capacities and the instrument interfaces, saving an unprecedented amount of measurement time.
Monitoring for correct, reproducible EMC measurements
The software also monitors the plausibility of measurement parameters and stores all information relevant to the measurement along with the measurement results. This allows R&S ELEKTRA to ensure the reproducibility and comparability of measurements, preventing erroneous measurements.
Immediately after measurements are complete, laboratory staff can obtain comprehensive test reports with the reliably repeatable measurement results. R&S ELEKTRA has its own SQL database in which test reports and dedicated measurement data can be collected and stored. Measurement data can be forwarded through a standard interface of this database to ERP or CRM systems, for example, and analyzed there.
The R&S ELEKTRA EMC test software with new and improved functions is available now. R&S ELEKTRA is compatible with all Rohde & Schwarz EMC test equipment and provides interfaces to integrate almost all existing equipment in the lab. Rohde & Schwarz offers comprehensive training and support for the introductory and changeover phases.
The post Rohde & Schwarz presents comprehensive R&S ELEKTRA portfolio for reproducible, standard-compliant EMC measurements appeared first on ELE Times.
Noiseless InGaAs IR sensor firm Phlux raises £9m in Series A round
CISM at Swansea establishes UK’s first capability for 4-inch gallium oxide thin-film growth
Latest issue of Semiconductor Today now available
I repaired my wah pedal
![]() | My Ibanez WD7 wah half-died (see: i damaged it). The "special" IC that created the effect (NJM2777) got damaged due to overvoltage. After trying a couple of circuits, this one is the one that won! V2164 (Quad-VCA) used with single supply, and TL072 for virtual ground and control voltage inversion. PCB milled at work's CNC (yes, i'm privileged😁) So happy i could rescue my 15year old beloved beast with ~€7 in parts (and saved ~150 for a new wah!) [link] [comments] |
Can a household manage on just 50 amps?

Today’s typical home is wired for at least 100-amp service, and many are wired for twice that number. This makes sense given the multiplicity of modern appliances and electronics in a home. The demand is obviously higher if you have an electric stove/range, or an electric vehicle using a basic in-house Level 1 charger.
The need for power—and more of it—became clear when a neighbor who was having a modest addition put on the house asked me for some advice. The situation was this: the contractor told him that for various reasons, their 100+ A service would be cut to 50 A for a month or two during the construction. The reasons for this cutback were not clear, but it had something to do with cable capacity.
The question I was asked was simple enough: could they—a couple plus two children approaching teen years—manage on just 50 A and, if not, what steps could the take to minimize disruption? (Actually, the word my neighbor used was “survive” rather than “manage” but I feel that’s overly dramatic.)
The semi-quantitative assessmentMy answer was also simple, as I gave the prudent engineering response “it depends” followed by “I’ll think about it and get back to you.” Then I set out to develop a firmer answer by doing some semi-quantitative assessment.
My first impulse was to check the web and, sure enough, there were plenty of apps for assessing house power needs. However, these required a detailed inventory of the loads which was more than I was ready to do. Then I thought I would create an Excel spreadsheet but soon realized that sort of analysis could easily become more precise than the problem merited. After all, my neighbor wanted a simple answer:
- It’s no problem,
- it’s definitely a problem, or
- it’s a manageable “maybe” problem.
Instead, I took out my “back of the envelope” pad and decided to do some rough assessments, Figure 1.
Figure 1 This “back of the envelope” pad serves as a visible reminder that rough and imprecise input numbers should get appropriate analysis and not impute undeserved precision to the results. Source: Bill Schweber
I didn’t actually use this custom-made pad, but instead I kept it in front of me as a constant reminder that I should stick to estimates that were rough enough that they could be added up “in my head” on that pad. The reason for this simplicity is there are a lot of fuzzy numbers in the assessment.
For example, without knowing the make and model of various higher-current appliances such as the electric stove/range, any number I did use would likely have a ±10 to ±20% error band. Further, while the individual errors might cancel each other out to some extent they could also accumulate, resulting in a fairly large error band. In other words, random errors can aggregate either way.
The danger when using a spreadsheet is that soon you fall into a mental false-accuracy trap, since its available precision of more digits soon leads to the sense that there is corresponding accuracy as well, which is clearly not the case here (yes, I could restrict the cells to a few digits, but that’s another thing to do). It’s been my experience that it is very easy make the leap from rough estimate to a firm “you can bet on it” number, even if there is no basis for doing so; I’ve seen that happen in preliminary design review meetings many times when the project manager asks for some numbers.
Complicating the assessment, some of the larger loads such as the stove/range or microwave oven are under the direct control of the house occupants, while others such as heating system, refrigerator, and separate freezer control their own on/off cycles.
Numbers guide but don’t proveI asked some questions about what was in the house, made a list, and went online to get a sense of how much current each uses. These rough estimates are for current consumption from a 120 VAC line; for those with 230 VAC lines, the current numbers should be cut in half, so that 50-A maximum would be 25 A:
1) Big loads you can’t control (these intermittent, asynchronous loads cycle on and off with unknown duty cycle; they may add up all at once, or hardly at all)
- Refrigerator/freezer: 6 A (will be higher for a few seconds, as the compressor kicks in)
- Separate outside freezer: 3 to 5 A, depending on outside temperature (same note as above)
- Oil-fired heating system: 5 A, temperature-dependent (same note as above)
- Electric water heater: 5 to 8 A
Total: around 20 A
2) Small loads (some you can control, some not; not an issue unless you are close to maximum limit
- Large TV: 1 to 2 A
- smaller screens: 0.5 A
- Various chargers: 0.5 A or less
- House lights: 0.5 A each
- House network boxes: 1 A
Total: 5 to 10 A
3) Bigger loads that you can control
- Clothes washer: 4 to 6 A
- Clothes dryer: 15 to 20 A
- Air conditioning: 8 to 10 A (but not a factor as this is a winter situation)
- Kitchen range top: 5 to 10 A, depending on model and temperature setting
- Kitchen oven: 8 to 12 A, depending on model and temperature setting
- Toaster Oven: 8 A
- Dishwasher: 9 to 12 A
- Microwave oven: 8 A
- Hair dryer: 10 to 12 A
Total: it depends on what you are using and when, but it adds up very quickly!
Conclusion: The loads you can’t control add up to around 25 A (all of these won’t be on 100% of the time) plus small loads of 5 to 10 A bring the total to 30 to 35 A, so the family will have about 15 to 20 amps of headroom on the loads that can be controlled. That’s doable but also cutting it close; you could have a case when just one additional modest load causes a droop and a brown-out of the supply voltage. That, in turn, brings on other operational problems in both motorized and all-electronic products.
Electrical service to older homesAs a curiosity, I checked out some older houses (1930 vintage) in the area, many of which are still occupied by descendants of the original families. Some of the present occupants said when the houses were built, they were outfitted with 30-A service and used knob-and-tube wiring rather than metal conduit or Romex (NM, or non-metallic sheathed) cable, Figure 2. While they have upgraded to 100+ A overs the years, some still have the knob-and-tube in the attic (not even close to code-approved now).
Figure 2 Early wiring used knob and tube insulation (a) which was replaced by (b) metal conduit (still in wide use) and (c) PVC-coated non-metallic sheathed cable, usually referred to as Romex. Sources: Arc Angel Electric Co., Meteor Electrical, D&F Liquidators
What’s your sense of the home-AC service situation? Have you ever been on a temporary or permanent limited-power budget at home? Have you ever had the corresponding “average load” versus “peak load” power-supply rating dilemma, either for line AC or with the DC supply in a product?
Bill Schweber is an EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features.
Related Content
- AC-line safety monitor brings technical, privacy issues
- Ground-fault interruption protection—without a ground?
- When extreme-precision numbers are legitimate
- Even a well-known numerical “constant” may need a major revision
- Why I’m fine with my calculator’s tiny decimal point
Reference
- Arc Angel Electric, “Understanding Knob and Tube Wiring: A Comprehensive Guide”
The post Can a household manage on just 50 amps? appeared first on EDN.
Power supply tester
![]() | submitted by /u/Important-Ad5990 [link] [comments] |
Yes, The Encoder final works.
![]() | submitted by /u/PulseStm [link] [comments] |
EEVblog 1677 - Why Do Fuses Do This? (EXPERIMENT)
LED Cube 🌈
![]() | submitted by /u/Dry_Sport6031 [link] [comments] |
Canadian tech accelerator engages Nokia in quantum telecom testbed

After quantum computing, quantum communication is now stealing the headlines. Numana, a Montreal, Québec-based non-profit technology accelerator, has engaged Nokia and Honeywell Aerospace Technologies in its Kirq Quantum Communication Testbed to advance quantum-safe communication networks. While Nokia will contribute its advanced cryptographic network technologies, Honeywell is to share quantum encryption techniques.
Read the full story at EDN’s sister publication, EE Times.
Related Content
- Quantum Computers Explained
- Hardware security entering quantum computing era
- A Global Race for Supremacy in Quantum Computing
- Toshiba Claims Breakthrough in Quantum Communication
- BASF and Kipu Focus on End-User Mastery of Quantum Computing
The post Canadian tech accelerator engages Nokia in quantum telecom testbed appeared first on EDN.
DNA scaffolds enable self-assembling 3D electronic devices
![]() | submitted by /u/Linker3000 [link] [comments] |
Pages
