A motley collection of ideas
This section is all about fun science and electronics, explained in a simple and playful way just for kids. If you’re curious about how things work and love tinkering or experimenting, you’re in the right place!
Dear Children, I thought I would show you a circuit that is not only for fun, but can also be useful at home for your parents and siblings. Surely it has happened before that someone forgot to close the refrigerator door, or didn’t shut it properly. This device gives a warning in such cases. Most … Read more
This circuit is a simple flasher that produces strong and short flashes. If you already know how a transistor works, you’ll have no trouble understanding how this thing operates. You can find the circuit on Tinkercad here: 👉 https://www.tinkercad.com/things/jn4ZX0OA4qi-flashing-light Although it works in a very simple way, this circuit actually exceeds the capabilities of Tinkercad’s … Read more
This circuit is a simple, contactless wire / mains voltage detector. It can detect 230 V mains wiring from a distance of 10–15 cm, indicated by a red LED and a buzzing sound. You can find the circuit in Tinkercad: 👉 https://www.tinkercad.com/things/cZa2iaSgAAG-wire-tracer The L1 coil is a self-supporting air-core coil. It can be made from … Read more
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
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
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
As I write these lines, there is half a metre of snow under the window and it is -10°C. The sunlight is playing nicely on the bruised trees, but the cold is evil. If we have to get out of our gloves, our fingers quickly get cold, our skin starts to burn. The blood circulation to the back of the hand deteriorates rapidly, and the gloves are of no use. It’s better to put your hands under a coat or use a hand warmer.
This article revives a classic from Janusz Wojciechowski’s cult book Building Electronic Toys: a simple Hartley oscillator that does nothing—except beep endlessly. I once drove my father crazy with it and today it’s still a perfect tool for learning electronics. We explain how it works, show how to rebuild it, and explore Wojciechowski’s quirky ideas … Read more
People have been sending secret messages since ancient times. Countless methods have been devised to protect information—and just as many to uncover it. Nowadays, digital methods are in fashion, and ciphers and chemical inks are more like toys, but there was a time when lives depended on them. Methods for concealing information fall into two … Read more