Inexpensive E-Scooter

In many cities you can see small electric scooters all over the place. You can rent as well as buy them, although at fairly high prices. Can much cheaper scooters also be used? An illustrated answer is given in this article, using the example of a dirt cheap e-scooter spotted among the 'weekly deals' promoted by a large supermarket chain in Germany.

One reason to play around with electronics is simply for the fun of it. For instance, you can build devices for making noise and producing sound effects. The fun project presented here is about building a police-style blue and red flashing light. Not a simple light with a blue and a red LED, no, this one has 36 LEDs of each colour. And it is not Arduino-compatible but uses an STM8S001J3 8-bit microcontroller instead.

Legions of dog whistles are available from pet shops and by mail order. But with only a few parts you can easily build one that yourself!

RC models like race cars and boats can be had very cheaply. Because of their low price they only feature binary controls like Left/Right and Go/Stop. However, an enthusiastic engineer can easily transform these controls into proportional ones if there is enough free space inside the model. Of course, it takes some fiddling and hacking to get it right, but that is exactly what you like about this hobby.

It seems to be an unwritten rule in Hollywood: there must be an assortment of devices that crackle and spark in the lab of a mad scientist. It doesn't matter that all those noises and flashes have no apparent purpose, as long as the effects look spectacular!

Candles are great during this time of the year (these dark days before Christmas), but are also a fire hazard, as we can unfortunately read again in the newspapers every year. Here is a non-hazardous alternative.

With the compliments of the Elektor Labs and Editorial teams, here comes another previously unpublished article that's free to download by all registered Elektor e-zine readers. "Free Fresh Articles" articles are published on a fortnightly basis in the Elektor e-zine. This time we have a contraption that automatically lifts a tea bag from a cup or glass of hot water after a preset time. It employs energy harvesting meaning the circuit works off the heat energy taken from the hot cup. And yes it contains a microcontroller, this time the extremely accessible ATmega169PA, with an LC display as a peripheral.

This project controls the brew time of a tea bag in hot water. The mechanics are controlled electronically, and the electrical energy required comes from contemporary energy-harvesting technology, specifically, from the temperature difference between ambient air and the hot water. Meaning batteries (dry or rechargeable), or even a power adapter, are redundant in this project.

If I had to choose a soldering station, I’d have a strong preference for the A-brands. It’s not a question of snobbery: in general, I only want to buy tools that I can enjoy using for many years. Quality and reliability are important factors, but the long-term availability of accessories or spare parts also plays an important role for me.

We already ran into them a few weeks ago: thyristors and triacs – semiconductor switches for DC and AC respectively. As with many other semiconductor devices, you can't tell from the outside whether they are okay. In such cases, a simple tester is extremely useful.