Yep, series mode protectors. Got a few of them. But when tstms threaten,
*everything* gets disconnected from the K3/K4, including headphones, key
and speakers.
73,
Drew
AF2Z
On 08/23/22 18:07, Jim Brown wrote:
On 8/23/2022 2:47 PM, David Gilbert wrote:
If I remember correctly, the laptop power supply was even plugged into
a quality surge protected UPS.
MOV Surge protectors short the phase and neutral conductors to the green
wire in the event of a surge. In the event of a strike, the IR drop in
the green wire raises the potential of the computer. It's common for the
potential difference between the computer and the chassis of anything to
which it's connected to fry either or both units. This is why MOV surge
protectors are a bad idea -- in systems where interconnected components
are powered from MOVs at different outlets, or to equipment that's
grounded, they are as likely to CAUSE destructive failures as to protect
anything.
We learned about this in the world of large sound systems more than
twenty years ago, started using series-mode surge protectors, which
store the surge in a very large inductor, then discharge it slowly. A
company called SurgeX, for whom I did some tech writing and teaching at
trade shows, licensed the patent for the pro audio market; two other
companies licensed it for the computer world and home entertainment
world respectively.
73, Jim K9YC
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