January 2024

Digital Q Meter

This project is a modern twist on a desirable but quite esoteric piece of test equipment. It displays the ‘Q’ or quality (the dissipative characteristic) of an inductor on an alphanumeric  OLED. The Q Meter is Arduino Nano-based and measures Q over a wide range, up to values of about 200.

Raspberry Pi Pico W Backpack

This update for our Raspberry Pi Pico Backback (March 2023 issue) adds Wi-fi support at a very low cost. It retains all the great features of the original Pico Backpack, including a dual-core 32-bit processor, a 480 x 320 px colour touchscreen, onboard RTC, SD card port, stereo audio and infra red receiver.  We provide software demos to demonstrate practical network applications of HTTP, UDP and NTP.

Active Subwoofer for Home Hi-Fi – Part 1

This is an uncompromising, high performance subwoofer design that can be used in virtually any application. It’s based on an SB Acoustics 12-inch driver and it incorporates a self-built 200W class A-B amplifier module. The Active Subwoofer will deliver up to 180W (continuous) in its current form. Part One of our project this month includes a full cutting list describing all the cabinet work needed, before we finish the constructional details in Part 2 next month. This is an exceptional constructional project that will appeal to every audio or Hi-Fi enthusiast – don’t miss it!

New series! MitchElectronics

This brand new series introduces beginners in electronics to simple, useful and easy-to-understand circuit designs. The basics of electronics never change, and this brilliant new series will help novices and students to get to grips with the fundamentals of using some basic, but essential, electronic components including the 555 timer and classic CMOS logic. LED projects this month include a simple light chaser, electronic dice and (British) traffic lights, and complete hobby kits are available for them too. A great way to get started in electronics!

Also in this issue:

• Techno Talk – Max reminisces on the progress of semiconductor fabrication densities over the decades.
• The Fox Report – Barry offers some practical tips to check AV and network cables, and challenges readers to provide solutions to some practical problems.
• Net Work – more surprising energy-saving insights, and a totally biased view about the world’s best mains plug – the British one! And, using an Ecowitt weather station as a home monitor.
• Max’s Cool Beans – Arduino Bootcamp (Part 13) – Max gets back to basics, discussing the fundamentals of interfacing an Arduino with LEDs and transistors.
• Circuit Surgery – Ian Bell continues his thorough grounding in the principles of superheterodyning  and frequency shifting, this month describing ‘superhet’ radio receivers in more detail, illustrated with LTspice simulations.
• Audio Out – discrete audio op amp (Part 4). This mini series rounds off with some circuit and component updates to the discrete op.amp

Next month

Advanced SMD Test Tweezers (Part 1); Active Mains Soft Starter (Part 1); Active Subwoofer (Part 2). Contents may be subject to change