AC power on front panels

Jim Beacon jim at
Tue Jan 17 12:15:57 CST 2006

> Thanks for that remark, Pete!
> I did not want to go into "pedantic" mode, but I was indeed
> thinking about the capacitors in the EMI filter, but thought
> that chances are very slim that they fail.  But they can!
> Once in ten years is good, except if it's *your* filter that
> fails :-)
> The caps in the EMI filter have a very small leakage current,
> so if you are 'energy-concious' pulling the plug is truely
> the only option.
> - Henk, PA8PDP.

We have PDPs on 24/7 at work, and have had the occasional controller
failure, but we have VERY sensitive smoke alarms and an on site fire
service! I wouldn't even leave one plugged in at home.

I have seen a number of failures of power supplies, especially the type
"designed" to be left on, often caused by poor manufacturing (badly made
transformers mainly), but, bear in mind that most electrolytic have a design
life of 10 years or less, leaving these things unattended is unwise.

I suppose you could go the route of using a remote monitored smoke alarm to
kill the power to your kit in the event of a little smoke.


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