Tag Archives: DIY

Nano sheet factory

via Dangerous Prototypes

Building a nano sheet machine @ Fablab RUC

Sometimes even very expensive and well build equipment breaks. This recently happened to researcher Biljana Mojsoska, a chemist at Roskilde University. She was working with nano sheets, an anti-bacterial coating for medical surfaces, as her machine stopped working.
The fact that such equipment can be so expensive to replace or repair triggered Jakub Klust and Bo Thorning at Fablab RUC. Could they build a machine with the same functionalities, using the equipment available at FabLab RUC? Would it be possible to build a much cheaper and easier to fix version of Biljana Mojsoska machine?

See the full post at fablab.ruc.dk.

DIY portable video conference, sharing and teaching device

via Dangerous Prototypes

A DIY conference and teaching device @ mcuoneclipse.com:

COVID-19 is by far not over, and in Switzerland the infection rate is going up again (2nd wave?). During the spring 2020 semester university lock-down we moved pretty much everything to a ‘distance learning’ setup. With that experience and with the request to prepare for the fall semester, I have constructed a DIY conference and teaching device which should make things simpler and easier: a combination of video camera, speaker phone and a muting device

Build your own HF balun

via Dangerous Prototypes

Miguel, EA4EOZ, posted this great DIY tutorial on building your own balun:

A balun is a MUST for dipoles or similar antennas when they are feed with coaxial cables. Many hams connect the center conductor of the coaxial cable to one side of the dipole, and the shield to the other. Wrong!
From the RF point of view, the shield can be modeled as two conductors, the internal shield (the real shield, this is, ground) and the external shield, who is really far to be ground. In this way, your dipole has 3 arms, the two from the dipole and the coaxial cable shield (external face).

See the full post on EA4EOZ blog.

DIY OpenDPS power supply

via Dangerous Prototypes

Evan’s DIY OpenDPS power supply:

Years ago I heard about the OpenDPS project to give open source firmware to cheap and available chinese power supplies. These aren’t strictly whole power supplies, they are configurable CC and CV buck converters. That means that it needs a stable DC source to back it to be used as a bench power supply. Perhaps you may not want to do this if you intend to use the DPS as a battery charger run from a solar supply or something, but most people I see want to use them for bench supplies so that requires an existing DC supply. Today I finally finished mine.

(Not a) triple tube geiger counter

via Dangerous Prototypes

Doz’ triple tube geiger counter project, that is available on GitHub:

So, two little switching power supplies, one for the DOB-50 and CTC-5 as they have similar operating voltages, and one higher voltage one for the DOB-80, a simple op-amp comparator to output the pulses to an Arduino to process and display the results.
The power supplies are controlled using two MC3406AD’s, driving an IRF840. I’ll just refer to the component numbers on the top supply, the bottom one is almost identical. The back EMF from the inductor L2 is rectified by a UF4007. There’s a feed back loop, R14,15 & 16 and the pot is used to adjust the HT..

More details on Doz’ blog.

Check out the video after the break.