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Banana Skins 57

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This issue of Banana Skins is split into two sections: the first (309-313) describes interference events that happened in 1995 or earlier, and the second (314-317) describes interference events that we might not be too surprised to hear about in or after 2015.

309 In its formative years, a major US PC manufacturer felt that FCC certification was not a barrier to marketing. Standard operating procedure was to sell while the authorisation process was in process. Then the FCC arrived to shut down the factory. The VP of Engineering met with the FCC in Washington at the last minute and worked out an agreement that kept the factory running. After that point, FCC certification and other agency approvals became a requirement before shipment was authorised. Today, that company has a world class compliance operation and I am proud to have taken part in that process. (Richard Woods, in a correspondence on the emc-pstc list server, 15 July 1998.)

310 The US Military first encountered Radio Frequency Interference (RFI) some time prior to World War 1 when a radio was first installed on a vehicle. (Warren Kesselman and Herbert Mertel, writing in the ?EMC Standards Activities? section of the IEEE EMC Society Newsletter, Summer 2000 Issue.)

311 A cleaner in the offices of a major UK car manufacturer started to use a new vacuum cleaner, plugging it into the sockets in a corridor outside the room where their stock control computer lived. Unfortunately, the mains sockets in the corridor were connected to the same branch of the power distribution as the computer, and the conducted noise from the vacuum cleaner crashed the computer. This happened ever day for some time, costing the company a great deal of money, until someone realised the vacuum cleaner was the cause of the problem. (Anonymous, private conversation with Keith Armstrong, August 1994.)

312 Transients in the mains supply of a gas station in the USA (called a petrol station in the UK) caused the spurious switch-on a microprocessor-controlled toaster one night after the staff had all gone home. Since the microprocessor wasn?t in its normal programme, it didn?t switch the toaster off. The manufacturer of the toaster had omitted to include a thermal fuse, so the gas station caught on fire and burnt down. The PCB had been designed by a UK company, and its designers were later questioned intensely by a team of US lawyers for several hours. (Anonymous, private conversation with Keith Armstrong, August 1994.)

313 Our purchasing manager has a penchant for (expensive) cars. He had a ?92 Peugeot 605, and whenever he drove past the military airbase at Lyneham its air bag indicator would light. This was attributed to the site?s radar interfering with the car?s front wheel sensors. In addition the semi-automatic gearbox would drop into sports mode? The ?93 model he now has appears to be immune. I myself suffered TV interference from ground radar when living 10 miles from Gatwick airport ? bars would roll down the screen as the sweep went through. (From Chris James, private communication with Keith Armstrong, 7th July 1998.)

314 A major electronics manufacturer has been ordered to suspend all sales in the EU while it fixes EMI problems with its products. Enforcement officials impounded products in warehouses throughout the EU. The average time to fix a product?s EMI problem is expected to be one month, but they have so many products that they expect it will be two years before they finish. They had argued that they thought the CE mark stood for ?China Export?, said no-one had actually told them they had to comply with the EMC Directive, and that they were only doing what many of their competitors were doing anyway. The enforcement agents found these arguments unpersuasive. (Possible electronic trade journal news item in 2015.)

315 Western military forces have come to rely (unofficially) on the widespread use of consumer (?COTS?) electronics such as GPS navigation, cellphones, and palmtop computers with wireless datacomms. Every soldier, sailor or pilot seems to own at least one of each, and they take them everywhere with them, including military exercises and operations. Some enterprising junior officers have even created their own ?command and control? nets, some of which seem to be much more effective than official ones. But during a recent NATO exercise based around the new SHIVA particle-beam anti-missile tactical battlefield man-pack systems, a large proportion of this COTS equipment failed to work and the unofficial methods that had grown up around them fell apart, causing great confusion. It had not been realised by how much these facilities had come to be relied upon. As a result, the ?attacking? forces easily won the exercise, despite being on foot, armed only with weapons of Afghan war vintage, and communicating by shouting loudly. (Possible article in Defence Review Weekly, 2015)

316 A number of people who had been enjoying weightless activities in the non-spinning central hub of Virgin Space Ltd?s newest hotel ?Arthur C Clarke III? found themselves trapped on the ?ceiling? for 15 minutes, unable to reach the doors which were now 6 metres ?up? a smooth wall. The cause was a new cleaning droid. When it plugged itself into the wall sockets in the corridor in the engineering section a 0.5g acceleration occurred. It was later found that the corridor power sockets were on the same branch of the power bus as the navigation computer, and conducted interference from the new droid caused the asteroid-avoidance emergency thrusters to fire. The droid has refused to comment. (Possibly from the Sunday Times News Review Section, one Sunday in 2015.)

317 The 30nm silicon fabrication process is now well-established and helping create many products and provide services that even ten years ago would have been considered science fiction. But investigations by York University into claims of unstable personalities in the latest models of robotic personal companions has revealed that ICs made with 30nm silicon features are very susceptible to the 76GHz radars used by the car-train systems required by automated highway systems. 76GHz automotive radar technology first appeared in the early years of this century as ?intelligent cruise control? or ?automatic emergency braking? systems for luxury vehicles, and is now ubiquitous. York University is now seeking sponsors for a programme of investigation into low-cost techniques for shielding and filtering at 76GHz. (Possibly from the News Breaks section of the EMC Journal in 2015.)


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