February 2025

Laser Communicator

This fun project is an ideal introduction to electronics, especially for younger aspiring constructors. It transmits audio over several metres using an optical beam, and uses classic transistor and audio amp components in a transmitter/ receiver pair. There are plenty of practical hints and tips in this full-length feature article that is bound to inspire a youngster’s interest in electronics.

Points Controller for Model Railways

Adding points to a model railroad layout increases its sophistication and realism, so now you can take your model railroad to the next level using this PICmicro-powered controller. It enables you to monitor and switch up to eight (if not more) sets of points. We also describe how to build LED-based signals to accompany each set of points. Uses through-hole components for ease of construction.

Mains Power-Up Sequencer (Part 1)

This PICmicro based project is a sophisticated solution to your power-up problems. It solves many issues caused when mains-powered devices switch on simultaneously, and helps avoid switch-on speaker thumps, circuit breakers tripping, brown-outs and spikes overloading home ITE gear.  It has four independent zero-crossing channels rated up to 10A in total and many start-up options and features to give you full control of your mains apparatus.

WARNING MAINS VOLTAGE
All circuitry within the Mains Sequencer operates at mains voltages. Risk of electrocution. This project may only be built by fully experienced competent constructors.

Weird & Wonderful Arduino Projects
Part 2: Power for our retro games console

Max looks into the LED strip topology that forms the display of his proposed games console.

Precision Electronics
Part 2: Op amps

This second feature article describes more techniques for working with op.amps in order to improve the precision available in measurement circuits.

Electronics: Inventors and their Inventions

Photo: Alan Winstanley

Part 2 in a wonderful and fascinating mini series detailing the many discoveries and advances in electrical and electronic engineering since their earliest days, some 200 years ago.

Also in this issue

• Net Work – Using the author’s Ecowitt Weather Station to tackle a humidity problem indoors, more news on Britain’s Small Modular Reactor programme and the author’s UK weather station goes online.
• Circuit Surgery – our regular monthly clinic continues on the advanced topic of digital signal processing.
• The Fox Report – Will Hi-Fi make a comeback, and news of the EU’s ill-starred ‘Digital Product Passport’.
• Practically Speaking – a welcome “heads-up” from Jake Rothman who’s currently in between setting up his new worklab.
• Techno Talk – Max milks some welcome praise – even though it’s from ChatGPT.
• Using Electronics Modules : 1-24V Adjustable USB Power Supply Our series this month offers a nifty little USB dongle with a difference – it’s a 5V USB powered variable power supply with LED voltage meter, providing 1-24V at up to 3W.

Next month – in the March 2025 issue

The Pico Gamer DIY retro handheld game; 10MHz to 1Hz Frequency Divider; Mains Power-Up Sequencer (Part 2)