New blog post: Infinite Ladder Network and Its Applications https://niconiconi.neocities.org/tech-notes/infinite-ladder-network-and-its-applications/
Explains the curiosity that the "golden ratio represents the input resistance of an infinite chain of voltage dividers with a pair of 1-ohm resistors". To convince the reader that this circuit is more than nerd-snipping, also shows the derivation of the transmission line impedance without using a single differential equation by cheating via industrial-grade hand-waving. Both are old electronics trivias and should be familiar to veterans in this field... #electronics
electronics
![Let Zin be the input impedance of the original infinite ladder network, now we apply a small modification to this existing network: install a new invented-L section (removing one also works). This creates a new circuit with a finite voltage divider of Zs and Zp, its center tap is connected to the modified infinite ladder network. Now, note that the infinite ladder network is infinite, its impedance does not change in spite of installing or removing a unit.
As a result, its input impedance before and after modification are both Zin equally!
Thus: [equations]
After expansion: [equations]
Solving this quadratic equation yields two roots: [equations]](/proxy/post_attachment/86282/2930317896.webp "Let Zin be the input impedance of the original infinite ladder network, now we apply a small modification to this existing network: install a new invented-L section (removing one also works). This creates a new circuit with a finite voltage divider of Zs and Zp, its center tap is connected to the modified infinite ladder network. Now, note that the infinite ladder network is infinite, its impedance does not change in spite of installing or removing a unit.
As a result, its input impedance before and after modification are both Zin equally!
Thus: [equations]
After expansion: [equations]
Solving this quadratic equation yields two roots: [equations]")
![Assume that every component of this infinite ladder is infinitesimal, and that Zs and Zp are inversely proportional to each other (inductor vs capacitor). By keep using the analysis method called “hand-waving”, we decide that Zs has no contribution to the final result, only the product ZsZp has. This would simplify the impedance equation to:
[equations]
Plugging the impedances of inductors and capacitors into the equation, yields:
sqrt(L/C)
This famous equation is the characteristic impedance of a lossless transmission line, of which its analysis is one of the most celebrated results in the history of electronics engineering.](/proxy/post_attachment/86284/e24dfb0e3b.webp "Assume that every component of this infinite ladder is infinitesimal, and that Zs and Zp are inversely proportional to each other (inductor vs capacitor). By keep using the analysis method called “hand-waving”, we decide that Zs has no contribution to the final result, only the product ZsZp has. This would simplify the impedance equation to:
[equations]
Plugging the impedances of inductors and capacitors into the equation, yields:
sqrt(L/C)
This famous equation is the characteristic impedance of a lossless transmission line, of which its analysis is one of the most celebrated results in the history of electronics engineering.")
New video! I'm building a simple 555 timer based logic probe from spare parts I had laying around.
YouTube: https://youtu.be/NhgjBUmnA7k
PeerTube: https://makertube.net/w/cuUPCfYmzMeL8DkFuXgW2a
#LogicProbe #DIYLabEquipment #LogicTester #NE555 #555Timer #Circuit #Schematics #DIY #Homemade #Electronics #Tinkering
New video! Replacing the broken fan in my ZD-915 desoldering station and performing some upgrades.
YouTube: https://youtu.be/26VEOadIn1M
PeerTube: https://makertube.net/w/d5jWSb4xnurBm8Qh6wC9GR
#ZD915 #DesolderingStation #Mods #Repair #LabGear #Electronics #Tinkering
My latest blog post: VanSpoof - Prototype 2 - Echo Firmware
https://mikecoats.com/van-spoof-prototype-2-firmware-1/
In part 1 and part 2 of building my first VanSpoof prototype, I managed to flash the microcontroller on the PCB with a blinky demo. This time round, let's see about sending and receiving some serial data.
#code #eBike #electronics #embedded #firmware #hardware #openSource #reverseEngineering #rust #rustLang #software #stm32 #vanMoof
My latest blog post: Low Tech Prototyping
https://mikecoats.com/low-tech-prototyping/
My existing prototypes are too big to fit on the bike, so I turn to one of my favourite low tech prototyping methods; 1:1 scale models in card and fibreboard!
I built a latency meter with an Arduino and a photo transistor to answer one question: Is click-to-photon latency higher on Wayland than on X11?
And the answer is: Yes, actually.
⏱️ 42 ms on X11, compositing off
⏱️ 56 ms on X11, compositing on
⏱️ 64 ms on Wayland
⏱️ 71 ms on Windows 10
Tested with Plasma 6.3.4 and Firefox 137. I will improve my methods and confirm these numbers. See replies for details.
#Arduino #DIY #Electronics #X11 #Wayland #Linux #KDE #Plasma #Latency #Performance #Gaming
Edited 129d ago
/me Learning how to take notes via SageMath and Jupyter Notebook to keep the algebra manageable. #electronics
#Electronics picks of the day:
➡️ @iFixit - Guides to repairing all kinds of electronics
➡️ @adafruit - Open source hardware manfacturer
➡️ @olimex - Different open source hardware manufacturer
➡️ @librepcb - Free open source electronic design automation suite
➡️ @kicad - Different free open source electronics design automation suite
➡️ @opelex - Project, wiki, podcast on open source electronics
➡️ @GurgleApps - Family videos about fun projects involving electronics, coding, STEM etc
🧵 1/6
Edited 98d ago
My latest blog post: Back 2 Basics - R-2R Ladder DAC
https://mikecoats.com/back-2-basics-r-2r-ladder-dac/
The first in a series of 'back to basics' projects, building real, practical, circuits. This time it's an R-2R Ladder DAC.
#code #electronics #embedded #esp32 #firmware #hardware #microPython #python
My latest blog post: I presented at the 2025 Open Hardware Summit
https://mikecoats.com/presented-at-ohs-2025/
Apologies for the break in blogging, but I've spent the past month preparing for, and then giving, my 'VanSpoof and F**dG3ar' talk at the 2025 Open Hardware Summit.
#electronics #eBike #hardware #OHS2025 #openHardware #openSource #reverseEngineering #vanMoof
My latest blog post: Metronalmost
https://mikecoats.com/metronalmost/
This metronome, by design, will never, ever, tick exactly once per second. This infuriating object is designed to thwart the goals of @hackaday's One Hertz Challenge contest.
#code #electronics #hackaday #microPython #openSource #openHardware
![Avatar for Ari [APz] Sovijärvi](/proxy/identity_icon/324990404716381522/3c248294d6.jpg){kind=icon}
Hello people! I've been on the Fediverse for couple of years now, so here's my re-#introduction
I'm Ari, better known by my tag APZ and this is my #pinball repair, #arcade and #retrogaming account. I mostly post about playing and repairing pinball machines, but I also work on #retrocomputing with all the classics.
An IT guy by day, I moonlight as a pinball arcade owner here in #finland with my partner @quester. This is purely a hobby of mine, I do this to keep my sanity and to keep pinball alive for the next generations of players. At the moment I own a bit over 30 pinball machines from 70s to 2020s.
A lot of what I do involves #electronics, #CAD for now obsolete parts and #3dprinting and tabletop #cnc to recreate them.
I love to #travel, usually to meet like-minded arcade collectors. I have a strong preference to #repair stuff instead of throwing it away. I'm a #linux user since mid-90s, having been part of #foss movement most of my life. I also edit arcade related videos.
Edited 38d ago
My latest blog post: Reverse Engineering a Broken Night Light - Part 1 - Tear Down
https://mikecoats.com/night-light-part-1/
We bought our first Night Light when our daughter was born; within 3 years, it and its replacement had broken. Let's tear it down, reverse-engineer what's left, and build it back up with some extra 'smart' features.
My latest blog post: Back 2 Basics - Op-Amp Buffer
https://mikecoats.com/back-2-basics-op-amp-buffer/
The second in my series of 'back to basics' real, practical, circuits. Today we're building an Op-Amp Buffer.
My latest blog post: Building the Kilnettle Tape Dispenser
https://mikecoats.com/building-kilnettle/
@stephencoyle presented his Kilnettle Shrine Talking Tape Dispenser as a Lightning Talk at the @oshwassociation 2025 Open Hardware Summit. He was kind enough to send me one to build.
Hi. I'm kbob. Intro time.
I used to get paid to write software. Now that I'm retired, I do it for free. I also play with 3D printers and electronics and stuff.
I love learning, and I like to make things the hard way. I often create a #BuildThread about a project and update it for months.
Interests
#3DPrinting
#CAD
#electronics
#FPGA
#synth
#BassGuitar
#solar
#geothermal
#homelab
#homeassistant
#pinball
#ev
#ebike
#biking
... and more
Edited 31d ago
My latest blog post: Back 2 Basics - NMOS Switch
https://mikecoats.com/back-2-basics-nmos-switch/
The latest in my 'back to basics' series. Toggle high-ish voltages and currents from a microcontroller using an N-channel enhancement mode Field-Effect Transistor, also known as an NMOS Switch.
My latest blog post: Admitting Defeat
https://mikecoats.com/admitting-defeat/
Sometimes you have to bail out before the sunk costs sink you. Having a good idea isn’t the same as having a good product.
#battery #cell #electronics #hardware #power #prototyping #usbC