On 2/25/2012 1:56 AM, The Daring Dufas wrote:
On 2/24/2012 8:14 PM, Pete C. wrote:

The Daring Dufas wrote:

On 2/24/2012 6:52 PM, gregz wrote:
"Pete wrote:
Metspitzer wrote:

On Fri, 24 Feb 2012 08:30:26 -0800 (PST),
wrote:

On Feb 24, 10:45 am, wrote:
Read up more on transformers...

Residential power is typically single phase (although there are
some exceptions to this) with a center tapped secondary winding
on the transformer...

The thing is, everything I know about electricity says that you need
TWO wires to make a complete circuit. AC or DC, doesn't matter.

Most streets have two overhead wires, with two wires going to the
transformer.

http://imgur.com/gFrGBr

I used 8000 for the primary from someone's earlier post. No clue what
it really is.

I believe 7,200V is about the lowest you will find anywhere and
most are
13,200V or more.

I was lying in bed one day watching guys adding a new transformer
outside
the window. When trying to clip the wire onto the hv wire I saw a
pretty
good arc. Probably at least 3 inches. A transformer feeding the
house burnt
out, so they replaced that, and added another transformer in
addition to
original. Result our house had less voltage fluctuations. When young, I
used to use the shortwave radio, and ever so often, maybe twice a ay, a
horrendous arching- buzzing sound would build up and quickly stop.
Lasting
3-4 seconds. I never found the source of that. Didn't sound like
anything
that would be consumer generated.

Greg

It could have been a static discharge from your antenna if you had an
external antenna. Or it could have been a static electricity discharge
from another source, even atmospheric. Another source may have been
power company or an industrial site switching high voltage power at
certain times every day. I can remember listening to distant stations
on an AM radio in different bands and hearing a "zip..zip..zip" sound
at regular intervals.

TDD

HID Street light ballast igniters are known to produce a lot of RFI when
they come on at night, and if they have a bad lamp attached they cycle
endlessly producing interference. With the switch to LED street lights
and even parking lot lights that problem should gradually become a thing
of the past.

A electrical engineer friend of mine was once the head of a power
company communications division and he told me that many complaints
of radio interference his department investigated turned out to be
caused by defective doorbell transformers.

TDD


Sounded pretty crazy the first time I saw you post it.

Jeff Wisnia came up with an FCC interference handbook
http://tinyurl.com/63ob78
or
http://transition.fcc.gov/ftp/Bureau...ceHandbook.pdf

that gives details. Some doorbell transformers have a thermal protector
on the primary that opens (and closes) if the transformer overheats. (It
may be part of the limitation on current/power for a class 2
transformer.) It can wind up cycling maybe 7 times a second. My guess is
that doorbell transformers have not been made that way for quite a while.

--
bud--