"Peter Lynch" wrote in message
...
On 2005-12-13, StudioTwo wrote:
Hello,

The past few weeks I have become aware of the house lights flickering
very slightly. I'm pretty certain it is not my eyes / imagination as it
is not something I have ever noticed in other buildings.

The effect is VERY slight but regular (approx 40 times per minute). It
is something I am aware of from time to time (so who is to say whether
it is intermitted or I just don't notice it). As i said, the effect is
very slight and it applies to lightling plugged into the mains sockets
as well as ceiling lights.

I have checked with my neighbours, but they have not noticed any
problem. Is this something that can be easily detected with the proper
equipment?

TIA
Stephen

When I worked in Wells we sometimes noticed this phenomenon. I was told
that the premises were near the end of a national grid line and shared
the line (we're talking high-power here) with a factory that made
supermarket trolleys. They spot-welded all the joints on each trolley
in one go and the instantaneous load dipped the mains voltage just
enough to cause a very short but noticable brown-out.

Possibly this is more/less noticable with incandescent lights as opposed
to fluorescent ones. Maybe your neighbours are on a different phase, or
just not as attuned to it as you are.

Pete

Pete's comments sound very logical; many years ago we had an major
industrial plant using electric arc furnaces connected to our main
electrical grid on its way to our (provincial capital) main city. When the
furnaces were operating the flicker was very noticeable; welding or other
similar momentary loads could easily cause similar effect.
Terry