Few words about me:From very childhood I loved computers, electronics, lasers, sulfuric acid and liquid nitrogen. I always wanted to be making microchips, UAVs and see nuclear explosion.
Now I am doing software engineering and in the spare time - some microelectronics and physics/chemistry experiments.
I live and work in Russia, Moscow.
Winter is coming : 1212 hours timelapse (50 days)Year ago I recorded 50 hour timelapse - now it's time for 50 day timelapse (1212 hours). Starting from green leaves to snow. Shooting on Xiaomi Yi, 1 frame per 30 seconds, and then - 16x faster in ffmpeg via frame averaging. Total video speed is 28'800х realtime. Original video was ~80 minutes, 28.7Gb (50Mbit/sec bitrate).
Lighting fluorescent lamp on a bench (with 400V/1A power supply)For a very long time fluorescent lamps were a bit of a mystery for me - how they should be preheated, what's up with negative resistance, striking - all this was not clear. Today, when LED dominate the world (except for applications with UV harder than 365nm) I got to figure this out. Main ingredient here is new product of Chinese engineering - HSPY-400-01 - 400V/1A DCDC power supply.
59kV is no jokeHV experiments no longer require dodgy DIY supplies: Chinese manufacturers (CXDZ) started to make affordable HV power supplies (in this case - 60kV/10mA). These are mainly used and designed for electrostatic air filters which are obviously a big business in China. Output is floating - so one can tie ether + or - to ground (that is especially important for X-Ray tubes with water cooling, where anode is touching the water and should be at ground potential).
This is ~10kV ~2mA discharge:
Mandatory warning: Anything above 50V can kill you in "suitable" conditions. Achieving that at 1-60kV is much easier.
Birthday PCBThis birthday I've got a PCB on the table. Fiberglass... Must be delicious
Growing mint and dandelionSome of you know that I like black tee, sometimes with mint. But buying good looking fresh mint is challenging. Obvious solution is to try to grow it myself. It also appeared to be not a trivial task as seeds are dust-like and quite hard to germinate. It was also hard to not forget to water it without auto-watering :-) Final result is pleasing:
Also I've planted dandelion (taraxacum) - but it might take a while more until it flowers. It was unexpected that literally no one sells seeds of dandelion in Russia - had to get it from Great Britain.
I've also shoot timelapse video of plants growth : first part is 40'000x realtime (2 weeks in 28 seconds, there is no wind there - it's natural plant movement during growth), second part is 6'000x realtime (during daylight movement is much faster as sun moves around):
Long journey to a decent 50x/0.8 microscope lensSome time ago I wrote that my old used 50x/0.8 Carl Zeiss Jena microscope lens appeared to be worse than my original Chinese one. This did not stopped me - I bought more modern used Olympus UMPlanFL 50x/0.8 lens - and it appeared to be even worse : it was probably dropped once or twice, so it was completely misadjusted and it's resolution was several times worse than difraction limited. This lens was sucesfully returned to the seller.
Finally I got older Olympus MSPlan 50x/0.8 - and this one appeared to be nearly perfect. It took me 3 trials to get a decent 50x lens - yet another remainder that buying optical goods on ebay require some caution and that good optics visually does not differ at all from the terrible one...
See below quality comparison of all 4 lenses.
First moments of 2016
First run of X-Ray tubeFor quite some time I wanted to build X-ray "microscope" in order to observe internals of multi-chip packages and MEMS (after etching often you cannot tell how it was assembled in the first place). Main concern is of course safety - I've got 12kg of sheet lead for shielding and radiation detector with thin mica window which could detect (but not measure dose!!) of very low energy x-rays. X-Rays with low energy (generated with 5-10 kV acceleration voltage) have very weak penetration power and could be stopped even by a sheet of paper. So at this point it is relatively safe with main safety issue being high-voltage supply and HV capacitors. Also beryllium from tube's output window is harmful.
For few years I was limited by X-Ray tube availability. I happen to get 1 BS7 tube (up to 15kV voltage) - it's power is only 0.02W, but spot size is extremely small and useful for x-ray microscopy - 2 µm. The tube worked fine, but when I got X-Ray fluorescent (intensifying) screen and was anticipating first photos - I opened box with the tube from the wrong end, it slipped and hit the floor. Getting a replacement was impossible - apparently production ceased in Soviet times, and replaced by modern models which could not be obtained that easy.
I was unable to get tubes from domestic manufacturers ("MELZ" and "Svetlana-rentgen"). But finally I was able to find BS5 tube from old Soviet stock - it is designed for higher acceleration voltage (30kV), power is 0.6W but spot size is also larger - 6µm. Friend of mine also got me BSV3 - Soviet monster tube with water cooling, made in 1964(!!!) - it was in storage all these years and it is still operational. Power is immense (400W), but spot size is extremely large, not really suitable for any microscopy.
Chinese lenses are still russian roulette
Tried new line of Chinese metallographic fluorite microscope lenses (LU Plan Fluor). M26 threading, 60mm parfocal distance could cause mounting issues on many generic microscopes. I was saved by 0-height adapters to M30 threading of my microscope.
The price is getting higher, 5x and 10X are 120-175$ each, and 50x is 460$. Unfortunately, they all disappointed me. Image quality with them dropped significantly to the corners and there were significant chromatic aberrations. They could still be better than "200$ for a set" microscope lenses, but not matching good Olympus ones. All lenses were returned to manufacturer.