Olafsen – Tech and more
Articles and notes on various stuff
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Repair of a Senseo With a Broken Hinge
Senseo machines are quite sturdy and long lasting, but the plastic exterior in this case was broken in the hinge part, connecting the cap with the main body. Another issue, common in the Senseo machines, was the rusting of the floaters in the tank, resulting in the machine never detecting the water level, always indicated…
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Check of Calibration of Cheap Temperature Humidity Sensors
Comparison of readings from common Chinese sensors with a reliable reference Chinese sensors for temperature and humidity like the one in the photo are very common and found also inside other devices, since they are extremely cheap and quite compact. They are even available with large digit temperature, or viceversa with large digits humidity. I…
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Output Impedance of Nexus 5X
Estimation of output impedance of the final audio stage In general, audio headphones should have an impedance of at least 6-8 times the output impedance of the final stage of the audio amplifier used to power them. Since my Nexus 5X is known to have a limited output power (up to 0.286 Vac) and my KNS-8400 have an input impedance of…
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Comparison Jack for Senheiser and KRK Headphones
Senheiser HD598, HD558, HD518, HD595 and KRK KNS-8400 Both companies provide some headphones with cables using a 2.5 mm jack and a twist-and-lock system. The cables for the KRK KNS-8400 are not easy to find so I checked if other companies sell similar cables. Also, I wanted to try to solve the issue of the microphonic…
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Measurements of DC-DC Converters
Oscilloscope tests to check shape, ripple, accuracy Update: for some more detailed tests, check this article. I bought some DC-DC converters to make a custom car USB-charger for my phone, able to supply more than 1.5 A on each USB port, with a good filtering of the spikes from the ignition coils and with low noise.…
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A Modified Bin Lock For VR100
Design of a better lock for the Vorwerk robot The vacuum cleaning robot Vorwerk VR100 is among the best ones, since it offers safe navigation in the apartment and accurate cleaning of all areas, thanks to the laser mapping unit that ensures complete and uniform coverage. Other vacuum cleaning robots are available, for example Roomba,…
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Estimation of Lead Contamination in 3D Printed Parts
Will lead from the nozzle make 3D printed parts non food safe? Sometimes people talk about the presence of lead in brass nozzles of 3D printers and about the related “issue” of using 3D printed parts, contaminated with lead, in contact with food or beverages. But is it really an issue? or is it something…
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Due scintille di luce nel buio della guerra
Oliviero Marzocchi racconta… Quando ero piccolo, agli inizi degli anni Cinquanta, alcune volte ho sentito mio padre raccontare ai clienti presenti nella sua bottega di sarto i seguenti due fatti avvenuti durante l’ultima guerra ed a lui riportati da mia nonna e da mia madre. Tedeschi Durante la ritirata, un gruppo di soldati tedeschi che…
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Automatic Power-Off of a Raspberry Pi
How to power off the system after shutdown My 3D printer is controlled by a SKR PRO control board on which which the firmware https://www.klipper3d.org/ is running. Klipper is a two-part firmware, which requires also another computer (typically a Raspberry Pi) to run the Klipper server. In my case the Raspberry Pi is powered by an ATX power…
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Duplicate File Finder for UNIX
POSIX-compatible script working also on FreeBSD I needed to find duplicate files on an embedded NAS4free install, lacking developer tools (gcc) and GNU utilities, often offering additional features compared to bare POSIX tools (see for example xargs, grep, sed, find). This means that I couldn’t use available tools like FSlint, DupeGuru or FDupes. Using my limited knowledge and a…