[Elecraft] [K3] KIO3 failure mode

[Drew AF2Z]

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
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to pubx1 at af2z.net