Sticky Plastics

Who hasn’t come across that moment when a formerly leather-like, silky-smooth coating on your stuff suddenly turns sticky? If it’s just a ballpoint pen that ends up in the trash because it’s gooey, you shrug it off. But when the kitchen knife holder sticks to the tiles—or worse, your e-book reader or an expensive studio … Read more

Regeneration of alkaline batteries

Manufacturers strongly advise against attempting to “recharge” disposable alkaline batteries. They claim the cells may leak corrosive electrolyte or the gas buildup during charging could cause explosions. Yet, these batteries can in fact be regenerated, which significantly reduces environmental impact and saves money. The regeneration of alkaline batteries is an old topic; even in the … Read more

How to Clean a Soldering Iron Tip

Back in our Pioneer days, many of us soldered with a Czechoslovak “instant soldering iron,” for which we bent the tip ourselves from stripped copper electrical wire. Today, a single tip for a modern soldering station costs around €3–5 HUF, so it’s not wise to waste them carelessly! There are plenty of guides online about … Read more

Repairing Braun M880M (4642) Handheld Mixer

This mixer did not fall victim to a teardown — it was repaired. The pictures show how it can be disassembled (not easy, but not impossible either). It was still manufactured at a time when the possibility was considered that someone might actually want to repair it. As can be seen in the pictures, the … Read more

Simple Bat Detector

Bats normally hibernate during the winter, but nowadays, thanks to the mild winters, we can encounter bats even in January. The real bat season, of course, begins in March–April and lasts until the end of October. This is the best time to go bat-hunting. In urban environments, the most common species are the serotine bat … Read more

An Alarm Clock and the Lifespan of Gadgets

In 1983, Rádiótechnika magazine published an article about a clock built around the TMS1122 IC. I redesigned the circuit and the PCB somewhat, then built it. It served continuously for 27 years, essentially without being turned off. Due to lack of space, I recently scrapped it, though it was still in working condition. The Clock … Read more

Nógrád Sour Cherry Cream Soup

This is the recipe of Professor Emeritus Vilmos Csányi, ethologist, academic, and writer. It is not a traditional Nógrád dish. The name comes from the fact that Professor Csányi’s house was in the village of Nógrád. According to Professor Csányi, the more complexly a civilization performs a task, the more advanced it is — judging … Read more

Repairing fluorescent tubes

Fluorescent lamps are becoming less and less fashionable these days, as LEDs are pushing them out—but they’re really not that bad. The technology improved a lot between the 1970s and 1990s: the unpleasant light of old fluorescent tubes is a thing of the past. Flickering and color distortion have been reduced so effectively that in … Read more

The Art of Seeing Air: Exploring Schlieren Photography

With Schlieren photography, even a person’s breath can be captured. It is often used to illustrate various flows, shockwaves, bullets, flames, and fire propagation. NASA has even developed a version of the method that allows supersonic aircraft to be photographed in flight. Most people have probably seen such images before — in recent years, the … Read more