RSA306 repair

2017-08-23 by rincewind

Fixing the broken USB connector on a RSA306

Low-Power Joule Thief Night Light

2017-02-19 by rincewind

The classic Joule-Thief circuit can be modified to work in a low-power burst mode: The base resistor R4 is increased to a value that provides just enough base current for startup. After startup, the base current is provided by C1 and transformer L1-L2. Each cycle, the B-E diode of Q1 charges C1 a bit, until[…] Read More…

A PLL-based 25MHz OCXO for the FZ7001 Frequency Counter

2014-09-17 by rincewind

Running the SI5351A with an external 10MHz reference Update 2017-10-02: Added Firmware archive, see bottom of page Update 2020-11-18: Added notes on generating your own frequencies for external clock on SI5351A Update 2021-06-03: Added Link to Dr. Simon Schrödle’s measurements   I own an old ELV FZ7001 frequency counter: However, after I got a used[…] Read More…

Microscope Mods

2013-11-24 by rincewind

Modding a cheap microscope to solder small parts @Work, we have a nice professional stereo microscope – with SMD parts getting smaller every year, this is a must-have for rework and inspection of PCB prototypes. At home, I mainly use a head loupe, but for really small parts, a microscope that has enough space to[…] Read More…


2013-05-05 by rincewind

Das MicroRobot-Projekt entstand mit dem Ziel, einen kleinen, extrem preiswerten Roboter-Bausatz zu schaffen, der von Schülern der 4. Klasse während einer Projektwoche aufgebaut werden kann. Da 25 Exemplare aufgebaut werden sollten, galt es, die Kosten möglichst gering zu halten – trotzdem sollten die Schüler den Mikrocontroller zu Hause selber am PC programmieren können, ohne dafür[…] Read More…