Svarichevsky Mikhail - RSS feed Svarichevsky Mikhail - RSS feed en-us Tue, 10 Jun 2006 04:00:00 GMT Wed, 19 Dec 18 10:37:15 +0000 120 10 <![CDATA[Internals of quartz wristwatch "Luch" - and some overclocking]]> There are some things which were around for so long, that we got used to them and take them for granted. At the same time sometimes they are much more complicated to design and manufacture.

My personal favorites are quartz wristwatches and film cameras. They only became accessible to everyone because hundreds of billions of dollars in R&D expenses were spent there in the past 1-1.5 centuries.

I'll take a look at quartz wristwatch this time. I'll look inside "Luch" wristwatch which I got during my school times.

Watches itself looks simple and ascetic. Wires are mine. You'll see why at the end of the article:

On the back side we can see an IC which generates 32768 Hz signal with a quartz, and outputs 0.5Hz signal. This signal is feed to a coil with insane number of turns (2.5kOhm resistance), which actuates the mechanics.

Closer look. Gears has 200µm teeth pitch. They are probably made by a precision stamping. BTW most advanced wristwatches use more advanced gears - cut using ion etching, similar technology to MEMS manufacturing.

Surely we'll take a closer look at IC (clickable). It looks like at the bottom there is an quartz oscillator, in the middle - 16-stage divider. Snake at the top is high-value resistor.

After metal etch:

Now let's take a look at quartz: it's classical tuning-fork in metal case, sealed by glass. Electrodes are deposited on the top:

One can spot dark line at the edge of the quartz... Let's take a closer look (clickable):

Enhance 224-176:

Enhance 34-36:

It looks like frequency of the quartz was fine-tuned by Q-switched laser. Before lasers quartz crystals were tuned by slowly lapping which was very tedious job (given 0.004% frequency tolerance).

But why there are pyramids over whole area of the quartz? Quartz crystals for wristwatches are cut on XY axis. When you process crystals (etch, grind) - they sometimes show anisotropy of their properties (etch rate or ease of chipping), which in this case left these nice pyramids in Z-direction.

Ability to pick arbitrary cut axis is what made quartz so ubiquitous. Different axis show different dependency of resonant frequency versus temperature. XY-cut has 0 frequency error around 25-30°С, which gives best results for wristwatches on your hand.

By choosing more complex cut planes - you can get curve with 2 crossing of 0 over wider temperature range. This is how we got AT-cut (99% of quartz crystals are of this type) and SC-cut (they are more suitable for ovenized quartz generators as they have flat region at elevated temperatures).

Older mechanical oscillators had no such ability and were linear, without any intrinsic first order compensation (and had much more external factors to consider - remaining power reserve, vector of gravity, magnetic field).

But the world made full cycle here and returning back to mechanical oscillators - MEMS-oscillators with all their dependency of external factors and lack of first-order self-compensation. All external factors had to be calibrated and compensated. In order to reach high Q-factor MEMS oscillators had to operate in vacuum - which make them susceptible to helium leaks (you might have heard about recent issues of inability of recent iPhones to operate in 2% helium atmosphere). All this is for reduced package size (especially thickness) and unified manufacturing materials.

But quartz will always have it's use due to combination of many advantages (low CTE, piezoelectric effect, ability to do a first-order frequency compensation, low jitter).

Fun time
Now it's time to overclock the clock. At realtime they run at only 1V, 394x overclocking requires 4.8V, 507.4x - 7V and finally 582x - 10V.

I was unable to reach 600x overclocking to cover 10 minutes in 1 second, but even 582x is extremely fast for mechanical system.

All these high frequencies are resonant, and only a couple of Hz wide. If you go 2-3 Hz lower - watches will go backward:

The hardest part of this article was not etching microchip in boiling acid. It was filming watch to hear it tick. Modern world make us too used to noise. I even had to move signal generator to a different room with a really long cable to get rid of 50Hz hum of it's power supply which I never heard before.

If you liked this - you might like too.]]>
Fri, 14 Dec 18 06:46:55 +0000
<![CDATA[Activiting Office 2019 without Microsoft account]]>
When releasing Office 2019 - Microsoft did another step in this direction and required to enter Microsoft account when activating your new Office 2019 purchase. If you don't enter account - activation will not finish, there is just no way to skip it in UI. Although, there is still a way to skip it via console activation... :

Run CMD.exe/Powershell with admin priveleges, go to "C:\Program Files (x86)\Microsoft Office\Office16" and run these commands:
cscript OSPP.VBS /act

Replace XXXXX-XX... with the actual key. Restart office programs - and enjoy your genuine and activated Office 2019 completely offline. I guess we cannot hope that Microsoft will realize the importance of having completely offline option of their products, so they will start (slowly at first) loosing users to older versions of Microsoft products and open-source alternatives.

PS. If you like OneNote - it's already time to start looking for open-source alternatives. Sorry Microsoft, I am not uploading my notes to you. ]]>
Fri, 16 Nov 18 07:00:26 +0000
<![CDATA[Sony a7III: Time for Full Frame 2 (and some PDAF striping/fake RAW)]]>

6 months ago I ebayed Sony A7II and thought that It will be with me for a while. But life is full of surprises - seller did not sent me few missing parts, I returned the camera... and by that time A7III was already released. There are quite a few nice features - BSI sensor with higher sensitivity, very pleasant high-ISO noise reduction, flexible autoISO settings... Some like larger battery and dual SD slot.

For me personally flexible autoISO is what gave me largest increase of good shoots yield. Also, now camera allows one to see the photos in the buffer while buffer is flushing to SD card.

After I was spoiled by zooms during ancient A-mount era ( I had Sony 16-50 F2.8 lens - it was quite sharp in the center and versatile) - here I bought loved by many Sony 24-105 F4. It was well worth it - even sharper and obviously slightly wider zoom range. Size and weight is probably maximum suitable for casual travel. F2.8 full-frame zooms in my view are only for professionals who used to lug a lot of equipment.

Fake RAW/star eater issue is still there. You can read more here, and sign a petition to Sony here. I was also able to reproduce PDAF striping issue under very exotic lightening conditions - but this is a topic for a separate article.

At the end, I really like the camera. It will definitely stay with me until 60+ megapixel full-frame cameras with 4K/60P full sensor readout are available. We might have to wait until 2022 for that...]]>
Sun, 01 Jul 18 20:12:56 +0000
<![CDATA[Soldering practice KIT - HKT002]]>
There is an 555 which frequency is set by long chains of capacitors and resistors. CD4017 johnson counter to drive 10 LEDs.
These 10 LEDs are driven by BJT's with high hFE and diodes in the base circuit, so any surface contamination from flux would not allow them to turn off LEDs.

Highly recommend to anyone who needs to solder from time to time. If you're just starting learning - you will need at least 2 set and lots of spare parts.

Here is last glitch: You can see 3 LEDs could be lit at the same time by CD4017. Why could that be?

One cannot use CMOS digital IC without decoupling. After adding decoupling it is rock solid:
Sun, 10 Jun 18 12:24:31 +0000
<![CDATA[Analog Devices AD9361 — when microelectronics is more profitalbe than drugs]]> still often an FPGA), external filters and PA if your task requires it.

Finally I was able to take a look inside and peek at manufacturing cost of a microelectronic device with such an exceptional added value.

After decapsulation we see 4336x4730 µm 65nm die. On top metal you can notice PLL's inductors and datecode - chip was somewhat ready 2 years before introduction:
Read more on →]]>
Fri, 25 May 18 07:33:02 +0000
<![CDATA[Weekend laser galvoscanner fun]]>

I exposed many cameras to direct laser beam many times in the past, but only now I got image sensor of my smartphone damaged (only color one, B&W sensor intact). That was quite puzzling at first, and probably I will need to write a short article later on on why some cameras are damaged by laser and some other (color) cameras are not.

Mon, 07 May 18 00:27:09 +0000
<![CDATA[PaperBack - proper way of storing information on paper]]> PaperBack made by Oleh Yuschuk.

While playing with it I was able to store ~500 KiB of data on a single side of A4, which could already have some practical use. This density is achieved at 300dpi data density, 80% dot scale (recommended value of 70% gave higher error rate) and 20% for ECC correction. For reliable recovery scanned image had to be slightly sharpened using Gimp2/unsharp mask, but it feels like this is the limit (ECC had to recover ~10% of errors). On 200/240dpi data density everything is much more reliable.

One can for example take a photo of the sheet using film camera and get data microfilms at home ))) Also, this data is easy to read even in distant future and does not depend on spefic reading hardware, so even aliens or humans 1000 years in the future who find a timecapsure with it would be able to read it...

Here is how data looks at 80dpi:


Now data at 300dpi, maximum for 600dpi printer:

Even closer (square side is 2.97мм). One can see that using less than 2*2 pixels for 1 bit of data would require different recovery approach due to very high rate of errors which will be pattern-dependent. Paper fibers would also cause some issues as higher data densities.

Sun, 17 Dec 17 21:19:42 +0000
<![CDATA[Olympus UPlanApo 10x0.4 WI - ultimate fun microscope lens]]>
Apparently I am a fan of water immersion. Last time when I've got 10x0.3WI lens I thought I am set for life. But recently I've spotted even more interesting lens on ebay: Olympus UPlanApo 10x0.4 WI. That would be my first apochromatic microscope lens. It's very large field of view and 0.4 aperture makes it ~1.8x harder to achieve uniform focus over the field comparing to 10x0.3 WI. But the information density is again ~1.8 times higher.

In the center of the frame new lens (on the left) is sharper due to higher aperture (0.4 vs 0.3):

At the edge we can see that lateral chromatic aberations are lower for APO lens (who knew?). Remainng lateral CA is probably caused by microscope's tube lens. I surely correct lateral chromatic aberration in software, but this lens makes it easier and cleaner.
Mon, 11 Dec 17 00:46:03 +0000
<![CDATA[Sony a7II: Time for Full Frame (and some fake RAW controversy)]]>
Finally I've bought my first full-frame digital camera - Sony A7II, on ebay as usual. While everybody were excited about A7RIII - I was quite disappointed: same sensor as in A7RII and still not solved fake RAW issue (it's there for all Sony camera's though). Why it is called fake RAW? Sony cameras has noise reduction algorithm which you cannot disable. It kicks in at long exposures and is applied even in RAW(!!!!), which completely ruins whole idea of RAW files (=direct stream of data from the imaging sensor for further advanced processing). The most obvious effect of this forced "noise reduction" is erasing 2/3 of the stars at the photos of night sky. You can read very detailed research of the problem here and you can also sign petition to Sony to finally fix it.

As my personal punishment to Sony I've decided to skip few camera generations: I will have fun in full frame with A7II for a while, just like 2 years ago I've started to get experience in E-mount with Sony NEX-5, which was ebayed for 110$. Hopefully some day they will release something like A9RII with 60mpix sensor and fixed fake RAW issue - this camera will be worth to buy new :-)

Glad that I did not ever bought full-frame A-mount camera (A900/A99 - it would have wasted much more money after re-sale), and a little bit sad that 3 years ago I've blindly bought Sony A77II instead of some E-mount camera (like a6000) which was already available at the time...

Sun, 10 Dec 17 04:32:10 +0000
<![CDATA[Slicing ruby like butter]]>
Photo cannot show incredible fluorescence of Ruby at 692nm - longest red wavelength, almost infrared... Deepest and most intense red that human eye can see...

Ruby rod has to be glued to glass holder with expoxy/UV glue:

Mon, 06 Nov 17 03:14:12 +0000