Fullscreen HTML5Med Res (??MB)HTML4

Practical Electronics Volume 54. No. 2 February 2025 ISSN 2632 573X Contents Projects and Circuits Laser Communicator by Phil Prosser 8 This fun project is ideal for learning electronics. It modulates a laser diode to transmit voice (or other audio) over several metres. The circuitry is quite simple and assembly is straightforward, so it is perfect as a teaching aid or introducing children to electronics. 37 Model Railway Points Controller by Les Kerr Adding points to a model railway layout makes it more fun and realistic. This Controller lets you monitor and switch up to eight sets from a single box with easy wiring. We will also show how to make LED-based signals to go with each set of points. 62 Mains Power-Up Sequencer, part one by John Clarke It solves many problems caused by powering up several devices simultaneously, like circuit breakers tripping and thumps from audio equipment. It can also power several appliances on or off when a ‘master’ appliance switches on or off. Series, Features and Columns 4 Net Work by Alan Winstanley I used a wireless weather station to banish indoor condensation; you can check the live weather data online. I also have an update on Britain’s Small Modular Reactor program. Circuit Surgery by Ian Bell Implementing digital sinc filters and simulating them in LTspice. 19 The Fox Report by Barry Fox Is Hi-Fi making a comeback? I also discuss the new EU digital tagging law. 24 Practically Speaking by Jake Rothman Some unusual things happened during Jake’s career working on audio electronics. 26 Techno Talk by Max The Magnificent 28 AI discovers the importance of flattery and it might be able to keep you company. Max’s Cool Beans by Max The Magnificent 30 Weird & Wonderful Arduino Projects, part two: power for our retro games console. Precision Electronics, part two by Andrew Levido 48 This series about precision electronics design covers a range of topics and uses real examples and real components to demonstrate the concepts. This one picks up where the last left off and goes into much more detail about how to use op amps. 54 The History of Electronics, part two by Dr David Maddison We wouldn’t have computers, smartphones or AI without the work of thousands of people who created the foundations of modern electronics. This second part describes significant discoveries by people born between 1804 and 1847. Using Electronic Modules – Adjustable USB Power Supply by Jim Rowe This surprisingly inexpensive module converts 5V DC from a USB port into any DC voltage between 1V and 24V at up to 3W. 73 Regulars and Services Made in Australia & the UK. Written in Britain, Australia, the USA and Ireland. Read everywhere. © Silicon Chip Publications Pty Ltd 2024-2025 Copyright in all drawings, photographs, articles, technical designs, software and intellectual property published in Practical Electronics is fully protected, and reproduction or imitation in whole or in part are expressly forbidden. The March 2025 issue of Practical Electronics will be published on Wednesday, 5th of February 2025 (see p80). Practical Electronics | February | 2025 Editorial AI is incredible but still in its infancy Reader services – Editorial and Advertising Departments Subscribe to Practical Electronics and save money Practical Electronics back issue downloads Practical Electronics PCB Service PCBs for Practical Electronics projects Classified ads and Advertiser index Next month! – highlights of our next issue of Practical Electronics 2 2 29 72 76 79 80 Renewals paid by PayPal, Visa and Mastercard are now handled via our website: www.electronpublishing.com 1