A motley collection of ideas
A popular variant of the well-known NE555 timer IC is the NE556, which contains two timers. With this IC, you can build a simple siren. This siren alternates between two tones, similar to old police car sirens, while also flashing a blue and a red LED. You can test the circuit in Tinkercad: 👉 https://www.tinkercad.com/things/lsxjw2LzvA7-police-siren … Read more
Barches, or challah, is a traditional baked good of Jewish cuisine: a braided yeast bread or sweet roll, sometimes enriched with potato. In families that keep Jewish dietary traditions, it is a customary element of the Friday evening Sabbath table. Details Serves: 4Preparation time: 1 hour Ingredients Preparation Sift the flour into a bowl and … Read more
This is a simple sound generator that can be controlled by light or by your fingertip. If you illuminate the photoresistor with a lamp or cover it with your hand, the pitch of the sound changes. You can try it out in Tinkercad: https://www.tinkercad.com/things/aEJgBAQp91s-fingertip-organ Instead of the photoresistor, you can place two bare wires that … Read more
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
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
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
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
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
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
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