Silicon ChipNet Work - April 2025 SILICON CHIP
  1. Contents
  2. Publisher's Letter: Equivalent Series Resistance testers are very useful
  3. Feature: Net Work by Alan Winstanley
  4. Feature: Max’s Cool Beans by Max the Magnificent
  5. Project: Calibrated MEMS Microphones by Phil Prosser
  6. Feature: The History of Electronics, part four by Dr David Maddison
  7. Subscriptions
  8. Feature: Circuit Surgery by Ian Bell
  9. Feature: The Fox Report by Barry Fox
  10. Project: ESR Test Tweezers by Tim Blythman
  11. Feature: Audio Out by Jake Rothman
  12. Feature: Techno Talk by Max the Magnificent
  13. Back Issues
  14. Project: Low-Noise Mains Fan Speed Controller, Mk2 by John Clarke
  15. Feature: Precision Electronics, part four by Andrew Levido
  16. PartShop
  17. Market Centre
  18. Advertising Index
  19. Back Issues

This is only a preview of the April 2025 issue of Practical Electronics.

You can view 0 of the 80 pages in the full issue.

Articles in this series:
  • Win a Microchip Explorer 8 Development Kit (April 2024)
  • Net Work (May 2024)
  • Net Work (June 2024)
  • Net Work (July 2024)
  • Net Work (August 2024)
  • Net Work (September 2024)
  • Net Work (October 2024)
  • Net Work (November 2024)
  • Net Work (December 2024)
  • Net Work (January 2025)
  • Net Work (February 2025)
  • Net Work (March 2025)
  • Net Work (April 2025)
Articles in this series:
  • Max’s Cool Beans (January 2025)
  • Max’s Cool Beans (February 2025)
  • Max’s Cool Beans (March 2025)
  • Max’s Cool Beans (April 2025)
  • Max’s Cool Beans (May 2025)
  • Max’s Cool Beans (June 2025)
Articles in this series:
  • The History of Electronics, Pt1 (October 2023)
  • The History of Electronics, Pt2 (November 2023)
  • The History of Electronics, Pt3 (December 2023)
  • The History of Electronics, part one (January 2025)
  • The History of Electronics, part two (February 2025)
  • The History of Electronics, part three (March 2025)
  • The History of Electronics, part four (April 2025)
  • The History of Electronics, part five (May 2025)
  • The History of Electronics, part six (June 2025)
Articles in this series:
  • Circuit Surgery (April 2024)
  • STEWART OF READING (April 2024)
  • Circuit Surgery (May 2024)
  • Circuit Surgery (June 2024)
  • Circuit Surgery (July 2024)
  • Circuit Surgery (August 2024)
  • Circuit Surgery (September 2024)
  • Circuit Surgery (October 2024)
  • Circuit Surgery (November 2024)
  • Circuit Surgery (December 2024)
  • Circuit Surgery (January 2025)
  • Circuit Surgery (February 2025)
  • Circuit Surgery (March 2025)
  • Circuit Surgery (April 2025)
  • Circuit Surgery (May 2025)
  • Circuit Surgery (June 2025)
Articles in this series:
  • The Fox Report (July 2024)
  • The Fox Report (September 2024)
  • The Fox Report (October 2024)
  • The Fox Report (November 2024)
  • The Fox Report (December 2024)
  • The Fox Report (January 2025)
  • The Fox Report (February 2025)
  • The Fox Report (March 2025)
  • The Fox Report (April 2025)
  • The Fox Report (May 2025)
Articles in this series:
  • Audio Out (January 2024)
  • Audio Out (February 2024)
  • AUDIO OUT (April 2024)
  • Audio Out (May 2024)
  • Audio Out (June 2024)
  • Audio Out (July 2024)
  • Audio Out (August 2024)
  • Audio Out (September 2024)
  • Audio Out (October 2024)
  • Audio Out (March 2025)
  • Audio Out (April 2025)
  • Audio Out (May 2025)
  • Audio Out (June 2025)
Articles in this series:
  • (November 2020)
  • Techno Talk (December 2020)
  • Techno Talk (January 2021)
  • Techno Talk (February 2021)
  • Techno Talk (March 2021)
  • Techno Talk (April 2021)
  • Techno Talk (May 2021)
  • Techno Talk (June 2021)
  • Techno Talk (July 2021)
  • Techno Talk (August 2021)
  • Techno Talk (September 2021)
  • Techno Talk (October 2021)
  • Techno Talk (November 2021)
  • Techno Talk (December 2021)
  • Communing with nature (January 2022)
  • Should we be worried? (February 2022)
  • How resilient is your lifeline? (March 2022)
  • Go eco, get ethical! (April 2022)
  • From nano to bio (May 2022)
  • Positivity follows the gloom (June 2022)
  • Mixed menu (July 2022)
  • Time for a total rethink? (August 2022)
  • What’s in a name? (September 2022)
  • Forget leaves on the line! (October 2022)
  • Giant Boost for Batteries (December 2022)
  • Raudive Voices Revisited (January 2023)
  • A thousand words (February 2023)
  • It’s handover time (March 2023)
  • AI, Robots, Horticulture and Agriculture (April 2023)
  • Prophecy can be perplexing (May 2023)
  • Technology comes in different shapes and sizes (June 2023)
  • AI and robots – what could possibly go wrong? (July 2023)
  • How long until we’re all out of work? (August 2023)
  • We both have truths, are mine the same as yours? (September 2023)
  • Holy Spheres, Batman! (October 2023)
  • Where’s my pneumatic car? (November 2023)
  • Good grief! (December 2023)
  • Cheeky chiplets (January 2024)
  • Cheeky chiplets (February 2024)
  • The Wibbly-Wobbly World of Quantum (March 2024)
  • Techno Talk - Wait! What? Really? (April 2024)
  • Techno Talk - One step closer to a dystopian abyss? (May 2024)
  • Techno Talk - Program that! (June 2024)
  • Techno Talk (July 2024)
  • Techno Talk - That makes so much sense! (August 2024)
  • Techno Talk - I don’t want to be a Norbert... (September 2024)
  • Techno Talk - Sticking the landing (October 2024)
  • Techno Talk (November 2024)
  • Techno Talk (December 2024)
  • Techno Talk (January 2025)
  • Techno Talk (February 2025)
  • Techno Talk (March 2025)
  • Techno Talk (April 2025)
  • Techno Talk (May 2025)
  • Techno Talk (June 2025)
Articles in this series:
  • Precision Electronics, Part 1 (November 2024)
  • Precision Electronics, Part 2 (December 2024)
  • Precision Electronics, part one (January 2025)
  • Precision Electronics, Part 3 (January 2025)
  • Precision Electronics, part two (February 2025)
  • Precision Electronics, Part 4 (February 2025)
  • Precision Electronics, Part 5 (March 2025)
  • Precision Electronics, part three (March 2025)
  • Precision Electronics, part four (April 2025)
  • Precision Electronics, Part 6 (April 2025)
  • Precision Electronics, Part 7: ADCs (May 2025)
  • Precision Electronics, part five (May 2025)
  • Precision Electronics, part six (June 2025)
Net Work Alan Winstanley This month I report on forthcoming ‘energy smart appliances’ and a reader highlights looming problems with Economy 7 electricity meters. I also reflect on nearly 30 years of using the Internet and the end of my regular columns (but maybe not the end entirely). S mart meters have been a hot Net Work topic for several years; the energy sector continues its drive to install them in every British home. There’s no doubt that many consumers appreciate having a smart meter’s in-home display (IHD) to track energy consumption, but BBC News reported that about four million of them currently don’t work properly. Much has been written about smart meters going ‘dumb’, having connectivity problems or sending inaccurate user data, resulting in overcharging. Some householders are even being paid to accept one: EDF (Électricité de France) recently offered the author a £150 bounty to sign up for a smart meter, claiming that my current digital electricity meter has reached the end of its life. This novel twist may finally tempt customers into accepting the latest SMETS2 (Smart Metering Equipment Technical Specifications) meter. I wrote half a decade ago (Net Work, January 2020) about how the concept of a Smart Meter Home Area Network (SMHAN) would forever alter how householders used appliances such as dishwashers, tumble dryers or electric vehicle chargers. Industry and the government are now talking about a new generation of ‘energy smart appliances’ (ESAs) as a way of managing Demand Side Response (DSR) – defined as “a means of changing electricity consumption in a way that benefits the electricity system”. ESAs have yet to materialise, but a voluntary EU Code of Conduct for ‘interoperability and energy smart appliances’ was adopted Germany last year, and the technical standards are now being hammered out. Once connected to a household’s SMHAN, energy smart domestic appliances would ‘know’ what the cheapest tariffs are at any time of day, and optimise the consumer’s energy usage and billing accordingly. This may well appeal to EV owners especially. Appliances are getting ‘smarter’ To see which way we’re heading, the British Standards Institute offers 4 heavy reading in a publicly available specification (PAS) in PDF format at https://pemag.au/link/ac4h I was gratified to read that the proposals specify a “…standardised control, subject to an explicit consumer consent, of energy smart appliances (ESAs) on an electricity network.” So consumers would have to opt in to take advantage. Like smart meters, ESAs will probably be touted as offering a consumer benefit, but the truth is that they’re all about rationing our faltering electricity supply. According to Electrolux, nine manufacturers in addition to Electrolux Group – including Miele, Turkey’s Arçelik, Mitsubishi Electric, Panasonic and Vaillant Group – have committed to the EU Code of Conduct and they promise to develop ‘interoperable connected products’ within a year, including washers, tumble dryers, dishwashers and heating/ventilation/airconditioning (HVAC) systems. My guess is that by the end of the decade, consumers will routinely sleepwalk into accepting this method of silently controlling their electricity consumption. Still, we will have to see whether ESAs will make much difference to our energy supplies. Not so economical There are problems looming for legacy meter users as well. Regular reader David Platt dropped me a line about another energy-saving problem he’s wrestling with: Being a retired coal power shift operations engineer, I follow your comments about the future progress of new energy generation with great interest, especially the advancement of SMRs, wind, solar and wave power. I have what is known as a “GEC Radio Teleswitch” (RTS) feeding a Siemens Normal/Low metering device. Are you aware that in June 2025, Octopus Energy is cutting off the Economy 7 radio signal, which is what my meter requires to operate properly? They propose giving me a new-fangled dumb smart meter instead. Is this signal cut-off common for all Energy Providers, or is this just a way to roll out the Government’s dumb smart meters? Can we stop the signal cut-off? Yours, David Platt MIET. The concern David highlights relates to the abandonment of the 1980s RTS long wave transmission, which takes effect on the 30th of June, after being postponed from 2024. The LW radio signal technology is deemed obsolete and unserviceable, so naturally all the electricity suppliers (not just Octopus) are pushing smart meters as its replacement. Some 600,000 meters are reportedly affected, and there isn’t really any technological alternative on offer today. For non-UK readers, Economy 7 and Economy 10 are cost-saving electricity tariffs that use a radio-controlled device to switch certain meters to cheaper off-peak rates, for seven or ten hours. There is more information about the RTS changeover at https:// pemag.au/link/ac4i As far as I know, having a smart meter fitted still isn’t compulsory, but if you use Economy 7 or 10, you will otherwise lose the cheap-rate tariff once the RTS is switched off. Unless they have a change of heart (which I doubt), I see no hope of extending the service. I’m afraid the outlook isn’t great for consumers who don’t want a smart meter. If no smart meter is fitted, the end user must bear the cost of ripping out the old equipment and updating his wiring. David later wrote to say that he had resigned himself to scouting around for a smart ‘dumb’ meter after all. When ill winds blow… We now have the ludicrous situation of sometimes paying wind farm operators not to generate power (shedding load) when it’s too windy, while paying end-users of the so-called demand flexibility service (DFS) not to use electricity at peak times either. There are signs that the novelty has worn off this incentive scheme as, according to the Telegraph, only 750,000 consumers remain in it compared with two million in the previous year. Practical Electronics | April | 2025 Britain’s costly quest for renewable energy is fraught with setbacks. Last December, the brand new 190-acre, 50MW Porth Wen Solar Farm in Wales, which was six years in the planning and construction, sustained severe damage caused by Storm Darragh and is already out of service. A nearby wind turbine also self-destructed because it was too windy. Such turmoil is likely to get worse over the next few years, and I reckon it’s maybe a decade away before Small Modular Reactors finally come on stream to provide a stable base load. EDF recently confirmed that two of its four ageing Advanced Gas-Cooled Reactors will now continue operating until 2027, and the remaining two can operate until 2030. The extra toll that electric vehicles and power-hungry AI data centres will place on the grid has yet to be played out, maybe helped by energy-smart appliance technologies. No-one knows for sure if wind and solar renewables will take up the slack in the meantime. For my part, I’ve stocked up on refills for my picnic stoves and portable heater, and I’ll keep a cupboard stocked with tinned food and bottled water just in case! CompuServe Information Services offered their first taste of going online. It was a ‘walled garden’ of CIS forums and correspondence via email using the CompuServe messaging system. A 1990s video titled The Kid’s Guide to the Internet was a nostalgic (if cringe­ worthy) intro that captured the zeit- Demon Internet’s Windows TCP/IP software included a dialler, geist 30 years ago. network tools, an email client and Usenet newsreader. It’s on YouTube at https://youtu.be/mfMrVKnGzwg It was slow going; a 5MiB file took After a rewarding period of authorhalf an hour to download, assuming ing using Locoscript on an Amstrad the line didn’t drop and one had to PCW9512 word processor, the IBMstart all over again. To save time and compatible PC beckoned me and, in money, ‘zipping’ large files was oblig1993, a new Ambra 486 PC arrived, atory, and arcane techniques such as with an internal 14.4kbaud modem UUEncode made transferring large providing dial-up access. files more feasible. I could also upload my monthly magazine ‘copy’ to the publisher by Here is the news direct modem-to-modem transfer, usOne key online attraction was Usenet ing Procomm Plus for Windows 3.1, or newsgroups, a system of static forums which saved me from having to post dedicated to a particular topic such as off a floppy disk. sci.electronics or comp.robotics.misc. In Britain, a fixed-rate ‘raw’ Internet It’s where I bumped into Clive (Max) Going full circle service was first supplied in the 1990s Maxfield, who at the time was heading The first Net Work column in August by London-based Demon Internet, in out from England to work in the USA, 1996 was just a single page, written to the shape of their ‘tenner a month’ and was a big fan of Practical Electronics. support users grappling with a newly (TAM) account. For £10, ‘Demonites’ The outcome of our chance encounter is emerging fad called the Internet. The could enjoy unlimited online access, evident in this month’s issue! buzzwords ‘Cyberspace’ and ‘Inforand so the author’s epemag moniker Mainstream Usenet morphed into mation Superhighway’ had entered was first created. The phone bill was Google Groups, support for which was our lexicon (they’ve pretty much left literally ¼-inch thick, listing 0845 discontinued in 2024 (https://groups. since), but home PC and laptop ownertelephone numbers to Demon’s neargoogle.com). Usenet still has its fans, ship had yet to hit the mainstream due est point-of-presence (PoP). and several paid-for services are sold to the high cost and complexity. Early Windows TCP/IP communicaonline. Usenet was also an open source The early Internet was mainly the tions software barely existed, and noof email addresses, which fuelled the province of computer enthusiasts, hobfrills, text-only DOS implementations first spam campaigns, and the scourge byists, academics and professional types. such as KA9Q were provided by Demon of junk mail started to fill our mailboxes. For many 1990s home computer Internet (see https://en.wikipedia.org/ If nothing else, these tentative steps owners in the UK, American company wiki/KA9Q). were a promising start, and then in 1995, new Turnpike for Windows software was launched. This program centralised a dialler, email, Usenet and other tools, making Internet access much more productive. Turnpike is described on Wikipedia at https://en.wikipedia. org/wiki/Turnpike_(software) With user numbers increasing exponentially, dial-up speeds edged up to 28.8k baud, then 33.6k and finally 56k, the maximum rate realistically achievable over copper wires. The demand for Internet access led to more British households ordering second lines, but there simply weren’t enough phone lines to go round. The temporary solution was DACSing (Digital Access Carrier System) as a A new 50MW solar farm at Porth Wen, Wales suffered major storm damage in December form of ‘line splitting’, which British and is out of action. A wind turbine was also destroyed. (Source: YouTube/NWSXS). Practical Electronics | April | 2025 5 c o v e r- m o u n t e d booklets listing the latest ‘mustsee’ URLs. There were even paperback book directories of website addresses! The idea of buying and selling on the web also took hold, although the UK was held back in this area by the dearth of availInside Amazon’s first book warehouse in Seattle. Founder Jeff able online payBezos being interviewed for TV by Robert Cringely in 1998. ment processing services. Then Telecom introduced to provide ‘virtual’ an online bookshop called Amazon phone lines, as noted in the Wikipedia sprang up. page at https://en.wikipedia.org/wiki/ Speaking in a 1998 TV interview Digital_access_carrier_system with Robert Cringely, Jeff Bezos reHome Internet users feared their counted how, in 1994, he learned that dedicated modem line being DACSed Internet usage was rocketing by 2300% because dial-up speeds could drop by per year, so he short-listed 20 products half, but BT were only legally obliged to that he thought he could sell online. provide a dial tone for voice calls, with He chose to sell books; his logic was no guarantee of data throughput. Mercithat so many book titles were available fully, I escaped the dreaded DACS. that it was impossible to list them in, say, a traditional printed catalog, so a A web of intrigue searchable website would be the perEarly on, the world-wide web fect solution. He then rented a Seattle (WWW) consisted of a smattering of warehouse and staffed it with Gen. Z websites and, compared with email, book lovers, and Amazon started shipUsenet or bulletin boards, the web was ping books all around the world. a lesser application for a while. Internet In the mid 1990s, I had a whale of a magazines sprang up that carried free time importing books at prices much lower than those seen in the UK, sometimes delivered before titles were even released in Britain. Initially, Amazon burned through cash and made heavy losses. Deciding whether Amazon would even stay in business became a sport amongst the commentariat. Amazon defied all the odds and expanded its range (“Everything from A to Z”), setting up shop in the UK and Germany in 1998, and the rest is history. A Oh No? Another turning Early eBay’s website was tightly designed and easy to navigate – point occurred in 1994, when Amer­ unlike the bloated one of today. 6 ica Online (AOL) users started to flood onto Usenet, trampling on established courtesies and usage protocols along the way (“Me, too!” was their oftenmocked catchphrase). AOL floppy disks and CDROMs rained down in a way we’d never seen before, in an attempt to batter potential customers into signing up to AOL’s fixed-rate service. As described in the fascinating Anglo­-American book net.wars by Wendy M. Grossman (New York University Press, ISBN 0-8147-3103-1), AOL also provided its customers with a direct route onto Usenet. The arrival of these Internet neophytes saw early ‘flame wars’ breaking out online, strictures about ‘net abuse’ taking shape and a general resentment amongst long-established, ‘professional’ and elite Internet users. It would be true to say that having an AOL address made you fair game for online abuse from intolerant old-timers or CompuServe users. That’s just the way it was, as the process of democratising the Internet got under way. Another Usenet trend emerged, first noted in about 1993, when cohorts of ‘newbie’ AOL users stumbled online every time a new University intake arrived each September. Many of the ‘net’s original unwritten principles, including observing ‘netiquette’, reading the ‘FAQ’ before annoying people with questions, and the need to ‘RTFM’ were ignored by those who neither understood nor cared. The fact was that the Internet genie had been let out of the bottle, and everybody now wanted to get in on the action. Portal websites, chat rooms, search engines and messaging systems were popularised as the Internet evolved at speed. Early forms of the eBay website described itself as “the world’s online marketplace”. Numerous online brands such as Alta Vista, Ask Jeeves, Excite and ICQ came and went, while others, such as Yahoo! and Netscape, still hang on in there today. Ironically, AOL eventually acquired CompuServe. The need for speed By the early 2000s, new ADSL (Asymmetric Digital Subscriber Line) ‘broadband’ services promised maybe 6-10Mbps download speeds using existing copper phone lines. Initially, many localities, including my rural one, were ruled out from receiving ADSL, as the focus was on kitting out urban locations instead. BT eventually introduced a system of drip-feeding the rollout of broadPractical Electronics | April | 2025 The speed checker at nPerf.com will display your Internet connection’s throughput and latency. devices connected to the cloud. The world has become smaller, and it has been fascinating to see BT’s unloved Broadband Availability Checker displayed local the impact that ‘expressions of interest’ before BT would consider installing ADSL. the Internet has had on our culture band by collating local ‘expressions of – quite a significant one, as it turns out. interest’. A tantalising thermometerstyle Broadband Availability Checker Reaching the peak showed when local targets had been My nostalgic journey over the past reached. Many users hated it, and they 30 years brings me full circle to the faced quite a cruel wait until ADSL present day. My work lab, which broadband expanded in the midstarted life with 14.4k dial-up, has 2000s. reached what is probably ‘peak InterBT then implored the trendy ‘new net’ as, against all odds, I successfully media’ industry to come up with mulinstalled fibre to the property a few timedia video, E-commerce, chat apmonths ago. plications and database-driven webThanks to a local ‘alt-net’ supplier, sites that could exploit these higher I now enjoy a more than adequate broadband speeds (more likely to fuel 300Mbps download speed, with up to the demand for ADSL). 1Gbps being possible – 70,000 times Consequently, websites became faster than my original dial-up! You more bloated and over-designed, in can check your own broadband speed sharp contrast to the tighter ‘informaat nPerf.com – see the accompanying tion silos’ that had preceded them. screenshot above. In this era, the so-called ‘Web 2.0’ My BT Openreach modem was rewas born, and email or surfing the placed by an Optical Network Terweb eventually became routine. Fibreminal (ONT), which terminates the to-the-cabinet (FTTC) then promised optical fibre that comes in through an faster-still data transmission rates, the outside wall (upstairs in my case – no ‘last mile’ being routed over existing need to dig up the road). copper wires to the property. My old SOHO router was swapped The Internet is now firmly estabfor a TP-Link EX230v, which has a lished as the fourth essential utility, separate VoIP (phone) port. Not everyand several young generations have one wants to be glued to their smartnever known life without it and all the phone all day, but what I thought pressures that it brings. Now Wi-Fi, would be the trickiest part – migratmobile smartphone data, satellite sering my BT landline number to the vices and fibre-optic based data comfibre service – went perfectly and it ms bring unlimited network access to was transferred on time, costing just everyday users, almost anywhere in £5 a month extra. the world. Voice calls now have a better qualMedia is now streamed to devices via ity than I can ever remember. Note an Internet feed, and homes bristle with that factory-resetting a VoIP router will all manner of smart ‘Internet of Things’ erase those landline config details, Practical Electronics | April | 2025 something that your ISP may need to restore again. Mains supply outages are another consideration, so my compact 9V and 12V UPS made by Power Inspired (see Net Work, December 2024) will hopefully power the ONT and router for a reasonable period. Installation and setup were free, thanks to the UK Government’s Gigabit Broadband Voucher Scheme (GBVS). The information at https://pemag.au/ link/ac4j was incorrect, though, and you should check the score with your chosen fibre supplier first. Pulling the plug I’m told that the entire world’s phone calls could pass through my single fibre optic connection. Maybe that’s sales patter, but things have come a long way since the 1990s when, just to check my email, I would unfurl a phone extension cable across the landing, like a sapper laying explosives, so that I could plug my modem into the phone socket upstairs. Doubtless, the arrival of full fibre broadband will open up new avenues to explore and keep me entertained and interested. With this in mind, I must also share the news that this month’s column is the last in the series of regular Net Work articles. After nearly 29 years, I’m now taking a well-earned break, but Net Work contributions may still appear periodically well into the future. I hope they’ve helped inform readers of new trends heading our way, as well as offering handy ‘heads-up’ reminders about getting the best from some current technologies. Many thanks to my regular readers for your feedback and kind comments and, in the meantime, I can still be contacted by email to alan<at>epemag.net as always, or via my website at www.alanwinstanley. PE com 7