A motley collection of ideas
For most of us, the Börzsöny Mountains bring to mind andesite, old mines and volcanic landforms. Yet one of the range’s most distinctive minerals is a genuine gemstone: almandine, the iron-rich member of the garnet group. Most Börzsöny specimens would hardly belong in a jeweller’s window, but they are all the more interesting geologically. These … Read more
You know that old Hofi Géza joke about “if you don’t have an aquarium…”? Well, I do have an aquarium. It has been fitted with 12 V LED lighting for quite some time. And there was a small problem with it. When a DC Connector Starts Getting Warm The lighting cable had a conventional round … Read more
Most Securit liquid chalk markers can be revived, as they feature water-based pigment ink and a valve-action system with a removable nib. The restoration steps: If the nib is frayed or permanently misshapen, Securit sells replacement nib sets, allowing you to keep using the marker as long as ink remains in the reservoir.
I came across the printed circuit board for this circuit completely by accident. It looked like an interesting and clever little design, and I had more than enough suitable parts lying around in my component drawers, including a pile of spare relays. So I decided to build one and measure what it could actually do. … Read more
This time, the device on the teardown bench is not broken. My Radtel RT-470 is fully functional and gets regular use; it simply needed a thorough cleaning. For that reason, I did not take it apart any further than what you can see in the photographs. Even so, there is plenty to discover about how … Read more
There are many reasons why duplicates appear in your catalogs but even if you are careful while you import photos, encountering duplicates is inevitable. Here is how to use the plug-in Teekesselchen to find duplicates of photos. This is a fast duplicate finder plug-in for Adobe Lightroom using EXIF meta-data. It requires Lightroom 3.x, 4.x, … Read more
A Honeywell XC100D carbon monoxide alarm that had reached the end of its service life recently came into my possession. At this stage, the unit may still appear to operate normally, but it can no longer be considered fully reliable. It signals this condition with a sharp chirp once every minute, accompanied by a flash … Read more
Kite flying is one of those rare pleasures that works equally well for children, grandparents and everyone in between. At its simplest it is a bright toy tugging at a line in the wind; at its best it becomes a quiet lesson in balance, air, tension and patience. And with competition kites — stunt kites, … Read more
The module shown in the picture can be purchased online for around 2–3 euros. It is a small “15 kV” generator suitable, for example, for secondary-school science experiments or for use as a negative ion generator/air ionizer. The circuit can produce a stable, high-temperature, high-frequency arc, which can easily ignite small combustible materials, such as … Read more
Generative AI—like Gemini—has become an essential daily tool for researchers, engineers, and academics. However, its use comes with a recurring professional pain point: handling mathematical and technical formulas. If you ask the AI to derive a calculation or specify a physical range, the output will almost certainly arrive in raw LaTeX format (for example: $550 … Read more