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My 24V 24A power source.
| I found it cheaper to buy lower amperage power supplies and having them in parallel instead of one with the same specs. I have made a passive balancer using 0.05 ohm resistors and one fuse so that one power supply doesn't works more than the rest. I am going to add ideal diodes to make it diode OR'ing to even further make the balancing better. Using this to drive a flyback transformer. The power supplies are 24V 6A so all four gives me 24V 24A. [link] [comments] |
Magnet-free electric motors: Driving innovation beyond rare earths
Electric motors are everywhere—from the cars we drive to the appliances in our homes—but most rely on rare earth magnets that come with high costs and environmental challenges. A new wave of innovation is changing that story. Magnet-free electric motors are proving that smart engineering can deliver powerful performance without depending on scarce materials.
By removing rare earths from the equation, these designs promise cleaner supply chains, more sustainable production, and fresh opportunities for industries ranging from electric vehicles to renewable energy. It’s a shift that could redefine how we think about powering the future.
Why rare earths matter
Rare earth magnets, especially neodymium and dysprosium, have been the secret ingredient behind the compact, high-torque motors that power everything from electric vehicles to wind turbines. Their ability to deliver strong magnetic fields in small packages has made them indispensable in modern motor design.
But there is a catch: mining and processing rare earths is energy-intensive, environmentally challenging, and geographically concentrated in just a few regions of the world. This creates supply chain risks, price volatility, and sustainability concerns that ripple across industries.
By understanding why rare earths became so central to electric motors, we can better appreciate the significance of moving beyond them—and why magnet-free designs are more than just an engineering curiosity. They represent a strategic shift toward resilience, affordability, and cleaner technology.
How do you pull without a magnet
So how do you build a motor without magnets? The answer lies in clever engineering that takes advantage of the natural properties of materials and the geometry of the motor itself. Instead of relying on powerful magnets to create motion, magnet-free designs use principles like reluctance torque—where the rotor naturally aligns with the path of least magnetic resistance—or induction, where currents in the rotor generate the force needed to spin.
These approaches may sound technical, but the idea is simple: by rethinking the fundamentals, engineers can coax motors into delivering the same performance we expect, without the rare earth magnets. The result is a motor that can be lighter, more affordable, and easier to manufacture at scale. And because these designs lean on widely available materials, they sidestep the supply chain bottlenecks that have long plagued magnet-based motors.
Why it matters
Magnet-free motors are not just an engineering breakthrough; they are a practical step toward cleaner, more resilient technology. By removing rare earths, manufacturers can cut costs, ease supply chain pressures, and reduce environmental impact.
The benefits ripple across industries: in electric vehicles, they promise more affordable and sustainable mobility; in renewable energy, they support wind turbines and other systems without relying on scarce materials; and in industrial machinery, they offer reliable performance with simpler, more scalable production.
In short, magnet-free motors matter because they combine innovation with real-world impact, helping power a future that is smarter, greener, and less dependent on limited resources.

Figure 1 Today’s magnet-free electric motors deliver high efficiencies for heavy-duty and commercial vehicle applications. Source: Advanced Electric Machines
Working principles of magnet-free motors
For learners, makers, and anyone with a curious engineering mind, the real excitement lies in how magnet-free motors actually work. Instead of relying on rare earth magnets to generate motion, these designs tap into fundamental physics—using reluctance torque, induction, or clever rotor geometry to produce rotation.
Think of it as guiding the motor to “want” to align itself with paths of least resistance, or harnessing currents induced in the rotor to drive movement. The beauty is that these principles are elegant, scalable, and rooted in concepts every engineer encounters early in their studies. By revisiting the basics with fresh eyes, magnet-free motors show how fundamental science can be reimagined to solve modern challenges.
At their core, magnet-free motors rely on clever ways to generate motion without permanent magnets, using principles that every curious engineer can appreciate.
That is, reluctance motors exploit the tendency of a rotor to align with the path of least magnetic resistance, producing torque through geometry rather than magnets. Induction motors create rotation by inducing currents in the rotor with alternating fields, a design that is simple yet powerful. Synchronous reluctance motors combine aspects of both, offering efficiency and control that rival traditional designs.
Each approach shows how fundamental physics—magnetic fields, current flow, and mechanical alignment—can be harnessed in different ways to achieve the same goal: reliable rotation. For learners, makers, and innovators, these principles are a reminder that rethinking the basics can unlock new possibilities for sustainable engineering.

Figure 2 A synchronous reluctance motor demonstrates magnet‑free operation with smooth torque characteristics. Source: ABB
It’s important to note that not all reluctance motors are the same. A synchronous reluctance motor (SynRM) runs in step with the supply frequency, using flux barriers in the rotor to align with the path of least magnetic resistance, delivering smooth torque and efficiency. A switched reluctance motor (SRM), by contrast, relies on sequentially energizing stator phases to pull a simple steel rotor around; it’s rugged and powerful but tends to be noisier with more torque ripple.
Sitting between these designs is the permanent magnet assisted SynRM (PMA‑SynRM), which adds small magnets to stabilize the field and boost efficiency while still using far fewer rare earths than traditional permanent magnet motors. Together, these variations show the spectrum of approaches engineers use to balance performance, simplicity, and sustainability.
Unlocking SynRM performance with VFDs
While SynRMs deliver smooth torque and efficiency, they typically need a variable frequency drive (VFD) to start and stay synchronized with the stator’s rotating field. The VFD supplies control frequency and voltage, making these motors flexible but dependent on modern power electronics.
By contrast, older induction motors could start “across the line”—plugged directly into the grid—though at the cost of high inrush currents and less precise control. This reliance on VFDs underscores how magnet-free motor innovation is inseparable from advances in drive technology, reminding designers that motor and electronics progress go hand in hand.
As a worthy side note, VFD is the electronic brain that makes modern motors flexible. By adjusting the frequency and voltage, it lets a motor start gently, avoid the punishing inrush currents of direct grid connection, and run at variable speeds with precision. For SynRMs, the VFD is essential—it keeps the rotor locked in sync with the stator’s rotating field. Older induction motors could start “across the line” without such electronics, but that simplicity came at the cost of efficiency and control.

Figure 3 A compact VFD module suitable for driving 3-phase SynRM motors supports efficient control in both industrial and household applications. Source: Mean Well
From a design standpoint, the dependence on VFDs is both enabling and constraining. On the enabling side, drives unlock efficiency gains, smoother torque, and precise speed control that make SynRMs competitive with permanent-magnet machines.
On the constraining side, they add cost, require integration expertise, and shift part of the reliability burden from the motor to the electronics. For engineers, it means evaluating magnet-free motors is not just about rotor geometry; it’s about the total system, where sustainability benefits must be balanced against drive complexity and lifecycle economics.
Note that modern control strategies such as field-oriented control (FOC) and sensorless vector control extend the capabilities of these VFDs. FOC regulates stator currents to deliver precise torque and flux, while sensorless vector methods estimate rotor position without mechanical sensors, reducing cost and improving reliability. Together, they allow SynRMs—and other magnet-free designs—to match the responsiveness and efficiency of permanent-magnet machines.
Quick FOC take: Field‑oriented control does not have to be daunting. For makers eager to experiment, compact FOC shields/modules provide a straightforward, low‑power entry point. The Arduino SimpleFOC Shield is a practical example, lowering barriers and making hand-on exploration accessible.

Figure 4 SimpleFOC Shield empowers accessible FOC experimentation for Arduino users. Source: Author
Next, getting into design significance, the combination of magnet-free motor design, advanced VFDs, and intelligent control strategies has broad implications. Engineers gain access to motors that are lighter, more affordable, and easier to manufacture at scale, while sidestepping rare-earth supply chain constraints.
In the long run, magnet-free motors not only reduce dependence on scarce materials but also align with global sustainability goals, positioning them as a cornerstone of next-generation electrification across industries spanning from manufacturing to consumer appliances.
Closing thoughts
Magnet-free motors are steadily moving from concept to reality, driven by both maker ingenuity and industry ambition. With BMW and Mahle advancing externally excited synchronous motors to reduce rare-earth dependence, and Tesla having already demonstrated the scalability of induction motors, the message is clear: sustainable propulsion can deliver performance without compromise.
For makers and engineers alike, this is an invitation to experiment boldly and rethink motor design fundamentals, because the next leap in innovation may emerge as much from a personal workbench as from an automotive R&D lab.
T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.
Related Content
- Designer’s guide: Motor control and drivers
- Driving higher levels of efficiency in motor designs
- Motor driver IC for BLDC, stepper motor deployments
- Motor control design: an introduction to motors and controllers
- Designer’s Guide to High-Performance Motor Control for Robotics
The post Magnet-free electric motors: Driving innovation beyond rare earths appeared first on EDN.
Power electronics evolve to maximize efficiency

Following the introduction of Industry 4.0, power electronics are becoming more significant in both digital and industrial infrastructures. Factories, energy systems, and data centers are getting smarter and more connected. This requires efficient power solutions that offer high power density and can scale with them.
Semiconductors are expected to deliver performance beyond the limits of conventional silicon-based power devices. Wide-bandgap (WBG) materials such as silicon carbide (SiC) and gallium nitride (GaN), as well as novel approaches to designing, packaging, and controlling power devices, are helping achieve the main goals of Industry 4.0: efficiency, flexibility, scalability, and intelligence.
800-VDC power architectureOne of the most significant changes introduced in the power system is the move of data centers to 800-VDC distribution, as detailed in an Nvidia white paper. Traditional systems that use AC and low-voltage DC can’t keep up with the speed and growth needs of AI-based workloads. High-performance computing clusters, especially those that support generative AI and machine learning, demand more power and should use it as efficiently as possible.
By raising the distribution voltage to 800 VDC, operators can reduce the current for a given power level. This approach offers the benefits of reduced I2R losses and the ability to use thinner wires. Overall, efficiency can thus be increased, and more power can be integrated in the same area or volume. The design also becomes less complicated because there are fewer steps in the conversion process.
This new architecture directly affects semiconductor requirements. Power devices need to perform well at higher voltages with minimum loss and support fast switching. Chipmakers and manufacturers are developing power solutions to support Nvidia’s 800-VDC power architecture reference design for next-generation AI factories to improve efficiency and reduce power losses.
To support gigawatt-scale AI factories based on an 800-VDC power architecture, Flex, for example, introduced a new reference design (Figure 1) that integrates power, liquid cooling, and compute capabilities into a modular assembly. This prefabricated solution streamlines the implementation of 800-VDC architectures and, according to the company, enables 30% faster deployment than conventional systems.
Figure 1: Flex’s reference design accelerates giga-scale AI factory deployment through a modular and preassembled structure. (Source: Flex)
SiC semiconductor advances
Due to its physical properties, such as high breakdown voltage, low switching losses, and high thermal conductivity, SiC can operate efficiently and provide high reliability in high-voltage and high-power environments.
At the high-voltage end, SiC devices are going into the multi-kilovolt range. More devices are gaining ratings above 1,200 V, making SiC more common in places where silicon-based power devices used to be the norm.
Navitas Semiconductor recently announced the availability of samples for its 2,300-V and 3,300-V high-voltage SiC products, specifically designed to increase efficiency in AI data centers, power grids, and renewable energy infrastructure. The devices, available in discrete, module, and known-good-die formats, are based on the company’s Trench-Assisted Planar architecture.
This semiconductor structure optimizes electric-field management, significantly reducing voltage stress and improving avalanche robustness compared with traditional trench- or planar-MOSFET designs. It also achieves lower RDS(on) at high temperatures and better current spreading.
As power devices improve, their packaging becomes increasingly crucial to the overall performance of the system. Newer packages are designed to reduce parasitic inductance, improve thermal management, and handle larger current densities.
These advancements in packaging technology enable higher performance and efficiency gains. Texas Instruments (TI), for example, recently unveiled two isolated power modules for applications from data centers to electric vehicles that require improvements in power density, efficiency, and safety. The UCC34141-Q1 and UCC33420 isolated power modules leverage TI’s IsoShield technology, which copackages a high-performance planar transformer and an isolated power stage, providing functional, basic, and reinforced isolation capabilities.
TI’s proprietary multichip packaging solution claims up to 3× higher power density than discrete solutions in isolated power designs and shrinks the solution size by as much as 70% by packing more power into smaller spaces. Applications range from factory automation PLC modules and EV and powertrain systems to grid infrastructure and rack and server power.
Wolfspeed Inc. has revealed that its 300-mm SiC platform, leveraging patent-pending innovations, is set to become a key material component for AI and high-performance computing (HPC) packaging by the late 2020s. Figure 2 shows a conceptual demonstration of an interposer substrate built on the company’s 300-mm SiC wafer. According to Wolfspeed, the SiC substrate helps to improve the thermal, mechanical, and electrical performance of next-generation packaging structures required by AI and HPC systems.
Figure 2: Conceptual demonstration of a 100 × 100-mm interposer substrate enabled by Wolfspeed’s 300-mm SiC wafer (Source: Wolfspeed Inc.)
GaN advances
While SiC excels at high voltages, GaN is suited for low- and medium-voltage applications, especially below 650 V. This semiconductor can switch at high frequencies, up to the megahertz range, with very low power loss, making power converters more efficient and smaller and requiring less cooling.
One important trend in GaN’s growth is integration. For example, Schottky diodes could be incorporated into GaN transistors to reduce losses from reverse conduction and make it easier to build power stages. Following this concept, Infineon Technologies AG has introduced the industry’s first industrial-grade GaN power transistors featuring an integrated Schottky diode.
Traditionally, GaN devices in hard-switching applications suffer from higher power losses due to their large body-diode voltage drop. This issue gets worse during the “deadtime” of a power controller. Engineers previously solved this by adding an external Schottky diode or complex controller tuning, both of which increase design time and costs. The new CoolGaN transistor G5 family solves this by integrating the diode directly into the transistor, reducing deadtime losses and boosting overall system efficiency.
Another important trend is bidirectional switching, where new GaN devices can block current and voltage in both directions. This simplifies converter topologies and requires fewer components. This capability is especially crucial for applications such as energy storage systems, EV chargers, and power-factor-correction circuits.
Renesas Electronics Corp. has introduced the industry’s first bidirectional switch (TP65B110HRU) based on depletion-mode (d-mode) GaN technology (Figure 3). Most current high-power conversion systems rely on unidirectional silicon or SiC switches that block current in only one direction. This limitation forces engineers to design multi-stage circuits or use “back-to-back” switch configurations, which significantly increases component count and reduces overall efficiency.
By integrating bidirectional blocking into one GaN product, this technology enables “single-stage” power conversion. The high switching speed and low stored charge of GaN also enable higher power density and switching frequencies. According to the company, this architecture has demonstrated over 97.5% power efficiency, providing a solution well-suited for AI data centers, on-board EV chargers, and renewable energy applications.
Figure 3: Renesas’s TP65B110HRU high-voltage d-mode bidirectional GaN switches (Source: Renesas Electronics Corp.)
Solid-state transformers
Solid-state transformers (SSTs) are a huge change in how power is transferred and controlled. SSTs are not like ordinary transformers, as they use power electronic converters to modify, split, and control the voltage.
Using this technology, more advanced features become available. These include two-way power flow, real-time voltage management, and the capacity to operate with renewable energy sources. Smart grids, microgrids, and Industry 4.0 all need SSTs that can change rapidly and easily. For SSTs to grow, WBG semiconductors are particularly significant.
For example, Infineon and DG Matrix, a company specializing in SSTs, have partnered to integrate SiC semiconductors into the Interport multiport SST platform. This collaboration aims to modernize the connection between the public grid and energy-intensive applications such as AI data centers, EV charging, and industrial microgrids.
Unlike traditional copper- and iron-based transformers, SSTs are semiconductor-based devices. They are smaller and lighter, accelerating deployment and providing higher power density. Adopting Infineon’s SiC technology, these SST systems achieve improved efficiency and reliability.
The technology enables direct power conversion from medium-voltage grid levels to the low-voltage requirements of modern digital infrastructure. DG Matrix plans to scale toward higher-voltage platforms to support the global rollout of high-performance power infrastructure.
The post Power electronics evolve to maximize efficiency appeared first on EDN.
У КПІ фахівці провідних енергокомпаній провели цикл занять для студентів-енергетиків
🔋 Представники АТ «Оператор ринку», НЕК «Укренерго», ПрАТ «Укргідроенерго» та ДП «Гарантований покупець» провели 6-7 квітня в КПІ ім. Ігоря Сікорського дводенний цикл занять для близько 60 студентів старший курсів кафедри електропостачання Навчально-наукового інституту енергозбереження та енергоменеджменту ( НН ІЕЕ) та кафедри електричних мереж і систем Факультету електроенерготехніки та автоматики ( ФЕА)
На війні загинув студент нашого університету Роман Андрійчук
🕯Зі скорботою повідомляємо, що на війні загинув студент нашого університету Роман Андрійчук
(02.02.2005 — 12.11.2023)
The Blink Sync Module 2: Faster response and local storage, too

The technology treadmill never stops, and so it goes with Blink’s second-generation hub device versus its predecessor.
Last month, I compared the conceptually similar (and thankfully, concurrent-use RF-compatible) hub-and-spokes approaches used by Blink and TP-Link for their respective battery-operated device ecosystems. Blink’s particular hub implementation, the first-generation Sync Module still in active use at my residence to this very day, doesn’t support local recording storage, only to the cloud, a service which fortunately is free for me (albeit in a somewhat limited-duration fashion) as a legacy customer.

(it’s more recently been moved from my office to the laundry room, and as regular readers know from other recent writeups, that Belkin Wemo smart switch above it is also now DOA)
Gratis capacity for non-geriatricsBut when I saw an inexpensive “for parts only” second-generation Sync Module available for sale on eBay, I still jumped on the opportunity, driven by curiosity. Primary differences between the two generations include, for the more recent model:
- A functionally active embedded USB-A connector, for mating with a flash stick or other mass storage device for local recording storage
- More robust, therefore more responsive, integrated processing, and
- Claimed wider-range Wi-Fi coverage
Turns out the device itself works fine, at least to the degree I’ve tested it so far; I was able to factory-reset it, and the Blink app can now “see” it (although I haven’t yet set it up). The only thing missing was the originally included AC/DC adapter with a micro-USB output, but I’ve got plenty of spares of those already, along with the one currently fueling its same-dimensions precursor in case I ever decide to upgrade in situ. So, let’s dive inside and see what we can learn, both in an absolute sense and relative to the first-gen Sync Module that I took apart…yikes….nearly seven years ago. Shall we?
Here’s today’s patient, as usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes:

All-important FCC ID (2AF77-H2121520):

Micro-USB power input:



and now-functional USB-A data port:

I wish everything I tore down was this easy to open up:



At this point…
Let’s pause a moment for some interesting (at least to me) background info. In re-reading my archaic first-gen teardown verbiage, I noted that I’d written (among other things) the following:
Today’s teardown candidate is that very same Sync Module. The one currently in use with my Blink XT cameras matches their black color; this particular one was purchased standalone off Ebay specifically for teardown purposes and is white (and previously used). Color scheme deviations aside, the two models are functionally identical.
I was right with my “identical” claim, at least with respect to the functional angle. And I’d already noted the color deviation. But further (and more recent) research has enlightened me that there were other (non-functional) hardware differences between my in-use device and the one I took apart, too. Blink actually brought to production multiple main variations of the first-generation Blink Sync Module (including a low-volume initial “launch” iteration), along with region-specific tweaks of each variant reflective of differing RF spectrum regulations:
There have been 5 main revisions of sync modules:
Version 0 which was white and has a (non-functional) ethernet port and (non-functional) USB and BLE (non-functional) available. This was the ‘launch’ era.
Version 1a which is white and has a (non-functional) ethernet port and (non-functional) USB.
Version 1b which is white or black and has a (non-functional) USB.
Version 1c which can be white or black and has no ports.
These were all the general ‘XT’ era modules.
Version 2 (the current one) which has a functional USB port.
All the modules are currently compatible with each other, but Modules 0, 1a,b,c have support ‘no longer guaranteed’.
However, this isn’t the end of the story, as the boards inside all come in combinations of EU and US and Intl flavors (due to regulatory / radio differences) too!
I’m guessing that the version I tore down back in mid-2019 was a “Version 1a”. I suppose it also could have been a “Version 0”, although I didn’t come across any Bluetooth Low Energy circuitry inside it. The one still in use here is a “Version 1b”.
Intra-generational variationWhen the Redditor who wrote the above shared his thoughts four years ago, there may have been only one (initial) version of the Sync Module 2 we’re looking at today. Fast forward to the present, however, there now have been (at least) two. The initial hardware was based on Atheros silicon for both the processor and Wi-Fi module; Blink subsequently switched to NXP-sourced ICs for both the processor and wireless subsystems, the latter this time supporting not only Wi-Fi but also both Bluetooth and BLE.
Onward. Remove two screws:

And the PCB pops right out:

You’ve already gotten a glimpse of the PCB frontside, so in fairness to its backside counterpart, let’s start there with the detailed analysis:
Admittedly, there’s not much of note, unless you’re into passives and embedded traces, that is. At lower left is the reset-and-pairing switch. And to its right is a Winbond W25Q256JV 256 Mbit serial NOR flash memory, presumably for system code storage. For comparisons sake, here’s the comparatively sparse backside of the first-gen Sync Module PCB:
Now flipping the PCB back over…
I didn’t bother expending much effort at peeling the initially stubborn sticker off the processor; I already know from the NXP logo visibly atop the chip in its upper right corner in conjunction with the helpful Wiki reference page I’d found that it’s the second iteration of the second-gen design, employing NXP’s MCIMX6Z0DVM09AB application processor with the following specs:
- ARM Cortex-A7 running Linux
- 900MHz
- SRAM: 128kB
- SPI/UART/I2C
- 96KB bootrom, 128KB internal RAM
- Has Arm TrustZone
That other NXP chip I previously noted is the 88W8987-NYE2 wireless “solution”. Below the processor is an ISSI IS43TR16640BL 1 Gbit DDR2 SDRAM. And at the top center of the PCB is one more notable (albeit tiny) IC. Labeled as follows:
455A
CQRX
220
It’s Silicon Labs’ Si4455 sub-GHz wireless transceiver, which (as the name) implies implements the proprietary long-range 900 MHz channel that Blink refers to as the LFR (low-frequency radio) beacon.
In closing, here’s the first-generation Sync Module PCB topside for comparisons sake:
And with that, I’ll turn it over to you for your thoughts in the comments!
—Brian Dipert is the associate editor, as well as a contributing editor, at EDN Magazine.
Related Content
- The Tapo Hub: TP-Link joins the low-bandwidth, long-range RF club
- Blink: Security cameras with a power- and bandwidth-stingy uplink
- Teardown: Security camera network module
- Blink: Security camera system installation and impressions
The post The Blink Sync Module 2: Faster response and local storage, too appeared first on EDN.
Marktech launches high-power 280nm UVC LEDs
Asahi Kasei and Kyoto University achieve laser oscillation in 2μm-band infrared PCSEL
Aehr’s quarterly revenue rebounds to $10.3m
There's some nasty ways to die out there as an insect... Being the short on a mosfett is probably up there at the top.
| Poor little bugger. [link] [comments] |
Tried PCB printing
| . [link] [comments] |
I did this thingy with this other thingy
| This is my project: ZVS feeding a transformer feeding a symmetrical Cockroft-Walton voltage multiplier. The circuit in the pic is the second part, earlier i posted the CW diagram that i designed with falstad. I study electrical engineering, and i decided to challenge myself with building this setup. The voltage between the 2 multipliers will be 240kV and produce ~30cm arcs(30cm according to gemini). I had problems with this ZVS and LTSpice, the simulation was harder to get going than the actual circuit, but today i succeeded with it. I think i'll reward myself with some ice cream later! :) [link] [comments] |
Battery gore
| submitted by /u/maifee [link] [comments] |
I accidentally fried my board and it somehow “fixed” the problem
| I’ve been working on a custom CH32V006 dev board for OpenServoCore, which is my attempt to turn cheap servos like the MG90S into smart actuators with Dynamixel-style single-wire UART. PCBWay kindly sponsored the fabrication and assembly for this first spin. When the boards arrived, I plugged one in over USB-C and immediately noticed the 3.3V rail LED was off. Measuring the rail gave me 0.84V. I checked all 5 boards and got the same result every time, so it was pretty clear this was not a one-off assembly issue. I even injected an external 3.3V supply directly onto the rail and it was still stuck at 0.84V. At that point the evidence was clearly pointing to my design, not the fab. After staring at the KiCad files and schematics for way too long and finding nothing, I started probing around different test points. At some point I hooked 3.3V up to what was labeled as the +3V3 test point for some reason. Then I heard a pop, saw magic smoke, and immediately assumed I had just made things worse. Then I looked down and the green 3.3V LED was on. What??? Measured the rail again: 3.3V. Turns out the silkscreen test point labels were wrong. That “3V3” test point was actually the EN pin between the MCU and motor driver. So by feeding 3.3V into it, I fried either the DRV or the MCU, and whatever burned open stopped dragging the rail down. In other words, I accidentally failed my way into a debugging success. From there I started removing parts on a fresh board one at a time. I removed the DRV, still 0.84V. Then I removed MCU, and the LED came back. After another round of staring at the schematic, I finally found the real root cause: I had accidentally swapped VDD and VCC on the MCU. It was staring at my face the entire time. Talk about shame... I ended up attempted three board surgeries and the third attempt finally worked with trace cuts and magnet wire, and somehow the CH32V006 survived reverse voltage on its power pins and still ran firmware afterwards. This little MCU is tough! It's not a failure if I never give up, right? I wrote up the full debugging story with photos and repair details here if anyone wants the whole mess. [link] [comments] |
Weekly discussion, complaint, and rant thread
Open to anything, including discussions, complaints, and rants.
Sub rules do not apply, so don't bother reporting incivility, off-topic, or spam.
Reddit-wide rules do apply.
To see the newest posts, sort the comments by "new" (instead of "best" or "top").
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Воркшоп «ШІ у роботизованих системах оборонного призначення»
КПІ ім. Ігоря Сікорського спільно з Міжнародним Комітетом Червоного Хреста провели воркшоп «ШІ у роботизованих системах оборонного призначення».









