(see house lights and garage fridge scene from "Christmas Vacation" for=20
reference)

A little over ten years ago I had a screw in medium base fluorescent=20
bulb with bad guts that
took down my home wifi network when turned on. That was a fun one to=20
chase down. :-)



On 12/15/2011 5:24 PM, Philip Pemberton wrote:
> Here's a nice little time-waster for you all...
>
> You have an opamp circuit breadboarded on the workbench. It's showing
> symptoms of oscillation, and the oscilloscope FFT shows a spectral peak
> at around 30kHz and ~25dB above the noise floor. There's a second
> (smaller) peak at around 9kHz, ~14dB above the noise floor.
>
> After several hours of head-scratching, circuit simulation,
> pen-and-paper recalculation and so forth, you decide to give up and take
> a breather. You turn the desk lamp off...
>
> And the circuit springs into life, the MCU boots, proclaims that
> "powerup diagnostics [have] passed", and proceeds to display perfectly
> valid A/D measurements on the serial port. The oscilloscope has also
> decided to behave itself -- the peaks are gone, replaced with the
> near-DC waveform that's supposed to come out of a well-behaved current
> sense amp.
>
> The lamp in question was later found to be emitting a 30kHz peak, plus
> harmonics beyond several MHz, and was more than capable of overloading
> an RF field sensor at a distance of a foot.. Its effects were still
> measurable on the other side of the room.....
>
> Some days, I hate this hobby. Other times, I just hate the offshore
> manufacturers who fill the market with garbage which doesn't even meet
> EMC regulations.
>
> Errgh.
>
> For anyone interested -- this is a Maplin A29FF "magnifier/desk lamp".
>     http://www.maplin.co.uk/22w-fluorescent-daylight-magnifier-lamp-47980
>
> =A340 for *this*...
>
>   =20

--=20
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