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IndrekR

1,961 karma · joined March 27, 2015

An electronics engineer. You can contact me via indrek@hedgehog.ee

Am open for good chat on topics that matter in life and elsewhere.

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IndrekR··on Operation Smart Kettle – Börzels Blog
It is not really just a kettle. Has integrated tea strainer, you can use it as a teapot.

It is missing a proper tea cosy, however.

IndrekR··on I refuse to let SPICE die
> with visualization on Linux

You mean ‘virtualization’ here, I guess.

IndrekR··on I refuse to let SPICE die
Major confusion for me, as SPICE is well known circuit simulator: https://en.wikipedia.org/wiki/SPICE

Using it often. Mostly via ngspice nowadays: https://en.wikipedia.org/wiki/Ngspice

IndrekR··on Extreme 220GHz+Broadband Silicon Capacitor X2SC 0201M 22nF BV11
Has been done for decades. Buried capacitance materials like FaradFlex MC12TM exist and are really good, but are not too often used.
IndrekR··on Extreme 220GHz+Broadband Silicon Capacitor X2SC 0201M 22nF BV11
The (more common) package has very precise solder bumps. You can have a special order for one with ENIG finish as well, but this only makes sense if you have a really good use case (using Pb solder, wirebonding directly). Not sure what method is used to deposit this solder. Probably just stencil on wafer before slicing.
IndrekR··on Extreme 220GHz+Broadband Silicon Capacitor X2SC 0201M 22nF BV11
Length of this capacitor is close to half-wavelength of 220 GHz (in vacuum).

Using siblings of this broadband capacitor (40 GHz, same package) in some designs. In assembly, those require decent process control. This 0201M package is closer to 01005 passives in pad size. Typically no solder paste is used, just flux. Solder mask alignment has to be very tight (thin web used as a dam only).

Cost per cap is reasonable where it is actually needed, other parts of the system are often orders of magnitude more expensive at those frequencies where performance matters. Where it gets the very high performance, is pillars/channels etched into silicon quite similar to how DRAM capacitors are made, just a “little bit bigger”. This allows for very low inductance and thus very high resonant frequency.

IndrekR··on Extreme 220GHz+Broadband Silicon Capacitor X2SC 0201M 22nF BV11
One scanner has way more than one channel…
IndrekR··on M 3.9 Experimental Explosion – 147 Km ENE of Ponce Inlet, Florida
0.018 kilotons. Order of magnitude smaller at minimum.
IndrekR··on WinUI 3 Performance: A Leap Forward
Jobs would have been lost with that move...
IndrekR··on Removable batteries in smartphones will be mandatory in the EU starting in 2027
Was discussed recently: https://news.ycombinator.com/item?id=47834195
IndrekR··on DaVinci Resolve – Photo
Have you tried Affinity Photo?
IndrekR··on Artemis II is not safe to fly
2/156 lost for Soyuz in 59 years, 2/135 for Space Shuttle in 30 years. Same rate. People often underestimate how intense STS actually was.
IndrekR··on Triplet Superconductor
In QC, keeping cold is not just needed to superconduct, but to reduce thermal noise to level below the energy levels operated at.
IndrekR··on How can I build a simple pulse generator to demonstrate transmission lines
I am using Leo Bodnar’s fast pulse generator (SMA) in my lectures to teach transmission lines. With sufficient length (I use ~1m) it works quite well to demo with a low cost scope. I originally bought it for TDR with 40GSPS/15GHz scope, which works very well with few orders of magnitude smaller lengths. Old on has upper length limit with 10MHz fixed frequency. There is a new one available with external sync and variable frequency, but I have not bought/tested it.
IndrekR··on What a year of solar and batteries saved us in 2025
> Except that after 11 years the equipment will have broken down or be obsolete, at which point you have to start over.

If my calculations are correct, that setup probably lasts at least 30 years. This is not a cell phone battery and panels do not degrade that fast.

IndrekR··on Start your meetings at 5 minutes past
A similar concept has been used for university lectures to start 15 minutes after the full hour. This was due to nobody having watches and everything being synced to the church bells ringing at the full hour. Then you had 15 minutes to get to the next lecture (in another building). Starting time was given as ct (cum tempore, with time) or st (sine tempore, without time). Usually only st was marked as everybody assumed the 15 minutes delay.

https://en.wikipedia.org/wiki/Academic_quarter_(class_timing...

IndrekR··on HPV vaccination reduces oncogenic HPV16/18 prevalence from 16% to <1% in Denmark
In my EU country Gardasil 9 is the most common HPV vaccine nowadays. This protects against 9 most common strains. I would assume the same is true in other countries. We have gone from HPV 16/18 -> +6/11 -> +31/33/45/52/58 protection with 2/4/9-valent vaccines.

Ref: https://en.wikipedia.org/wiki/HPV_vaccine

IndrekR··on Tesla’s 4680 battery supply chain collapses as partner writes down deal by 99%
If the input to the weather forecast is mostly /dev/random, then yes, that is called a lie. There is a very big difference between modelling chaotic systems and providing random noise.
IndrekR··on US blocks all offshore wind construction, says reason is classified
Taiwan strait is filled with offshore wind turbines from both sides. This is not an issue for PRC nor Taiwan.
IndrekR··on How a devboard works (and how to make your own)
Few things for starters:

- you have to look at it in frequency domain as well;

- speed of light is too slow;

- often capacitors are inductors, even more so when mounted on PCB;

- capacitance is not what is written on the component.

I am teaching this to robotics and computer engineering MSc students. Quite nice intro book into the topic that I recommend to my students: https://www.oreilly.com/library/view/principles-of-power/978...

IndrekR··on The Trinary Dream Endures
Most common quaternary storage system is probably DNA.
IndrekR··on What Americans die from vs. what the news reports on
Funny thing is, that news, by definition, are written about things that are newsworthy. Newsworthy things are not common, but exceptional and rare. Thus one shall not worry too much about the news as those things practically never happen in everyday life.
IndrekR··on Signal Protocol and Post-Quantum Ratchets
In signal you can change your username any time.
IndrekR··on Bank of Thailand freezes 3M accounts, sets daily transfer limits to curb fraud
The funny thing is, that MM in roman numerals means 2000.
IndrekR··on Bank of Thailand freezes 3M accounts, sets daily transfer limits to curb fraud
It is to avoid confusing with "M", mīlle -- Latin for "thousand". Quite common in financial world still.
IndrekR··on Florida lawmaker floats ban on HOAs amid growing backlash
HOA = Homeowner association

Took me a while to figure this out.

IndrekR··on In 2006, Hitachi developed a 0.15mm-sized RFID chip
Used to develop readers based on similar UHF chips (868 MHz in EU). They were quite expensive compared to printed bar codes those were replacing. Also large. With (folded) antennas we are still talking about 40*10 mm minimum for the label. You can not use them on metal surfaces. Readers nearby will interfere as it works by EM wave backscattering, unlike NFC which is essentially a transformer (with electric field intentionally supressed usually). I think it still is a solution looking for problem. QR codes are cheap and NFC (14 MHz) readers are everywhere.
IndrekR··on The future of large files in Git is Git
Letsencrypt was founded 2012, but become available in the wild December 2015. git-lfs mid-2014. So same era in general.
IndrekR··on QNX: The Incredible 1.44M Demo
This demo seems to be dated 1999. I recall the context where and when (school) I saw it first and I moved to a different school in autumn 1998. It seems there was an even earlier disk that I am confusing it with:

https://marc.info/?l=freebsd-chat&m=103030933111004

IndrekR··on Linux Reaches 5% Desktop Market Share in USA
I would not be too surprised to find out that significant portion of Linux on Desktop here is actually headless Chrome web scraping.
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