Add Proportional Speed Control to Your On/Off RC Model

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With the compliments of the Elektor Labs and Editorial teams, here comes another previously unpublished article that's free to download by all registered Elektor e-zine readers.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.

A liquid-resin 3D printer offers much higher resolution than a filament 3D printer. The Photon-S printer from Anycubic we tried out features a layer thickness of the order of 10 microns. Besides being very precise, it's very affordable as well.

With the compliments of the Elektor Editorial and Labs teams, here is a 'fresh' article presented free of charge to all Elektor e-zine subscribers. This time we have author Willem Tak discuss an upgrade to an earlier project publication. Willem was prompted by non-availability of a few, let's say, key components. We really like reader's contributions describing how published projects get enhanced, updated and tweaked so here goes with suggestions for new components, and software to put in the 2018 "Multi-Timer".

Techniques that used to be available for multi-million defence projects only are becoming more affordable. Take lidar, short for Light Detection And Ranging, a 3D laser scanning method for mapping the environment. Initially intended for satellite tracking, today you can buy a miniature lidar for under €100. Add the software from this project and away you go (your robot, of course).