On Wed, 19 Dec 2012 07:26:37 -0800 (PST), klem kedidelhopper
wrote:

On Dec 19, 5:53*am, "Mark Zacharias"
wrote:
"klem kedidelhopper" wrote in message
...
On Dec 18, 7:16 pm, John-Del wrote:
Surely the idea is to replace the blown bulb when noticed ??

Why wait until the situation you described develops ??

If you notice them... These miniature lamps are usually wrapped around
trees or otherwise stuffed into decorative foliage, and single lamp
failures often go unnoticed unless you're specifically looking for them..
Lenny's idea of adding lamps in series is a good idea. Years ago, I had
an X10 setup for holiday lighting, and would run the dimmer modules for
the light strings. Just dropping the brightness a bit kept them running
almost forever.

My son just bought a set of similar lights that use LEDs. We'll see how
long these last.

I took a good look at these lamps tonight under *a magnifier, I
noticed a very curious thing. At the base of each lamp the thin wires
go through the bulb and attach to the posts that the filaments are
then welded to; If you look into the bulb, at the base of these posts,
inside each lamp there seems to be a thin wire wrapped around the
posts that one would think would short them out. It obviously doesn't
happen right away but after a period of time, (heating), it does seem
to. Perhaps that is it's purpose, to burn through an insulating layer
on the posts after a brief time and destroy the lamp. And one further
observation. In looking at the filaments on all the "shorted" Kamakazi
lamps *It appears that the filaments never opened, rather the shorting
wire must have finally burned through the posts and shorted the lamp
out.
What an insidious clever way to *sell more Christmas lights. Isn't it
fascinating the lengths that some people will go to to separate us
from our money? Merry Christmas! Lenny

Or, keep the remaining series string going even after the lamp burns out.

Mark Z.

Thank you Gareth. I did miss that link. So it seems that my theory
about the short,(shunt) was pretty much right on the money, except for
one thing that is. The article mentions, as I had suspected that when
the filament opens, current then flows through the shunt. This heats
the shunt, thereby causing it to melt it's way into the posts and thus
providing continuity to the series string. Although that does sound
ingenious, as I had mentioned in my last post, upon examining each
"shorted" lamp under high power magnification it appears that in
almost every case all the filaments appear to be intact. That would
suggest that this melting and subsequent shorting of the lamp occurred
before the filament opened. Naturally I couldn't measure these
filaments with the short across them to confirm this, but they do look
to be mechanically sound. So I guess what it comes down to is I think
that we're being screwed with these Christmas lights. As an
interesting side note. I have considered using some of the surviving
lamps in parallel as low voltage "street lights" and to illuminate
model buildings on my Lionel train layout. I'll be sure to fuse the
circuit if I do.... Lenny

One comment on this topic... These strings with the shunts are not
new. They have been around for decades. When I was a child (a long
time ago), they used series strings of regular bulbs. If one went
out, they all did. The next advance was parallel bulbs. That solved
the problem, but they were expensive. Later (1970's?), these mini
bulbs with the shunts came out. I could be off on the decade, but it
has been a long time. In my experience, bad connections are more
common than bad shunts, but I have seen my share of actual burned out
filaments, too. With the new LEDs (now that they figured out "warm"
white), the only problem we will have is bad connections ;-)
Pat