Lazy guy that I am, I installed "touch switches" in the bases of four
metal bodied table lamps in our home, two on the end tables next to our
living room sofa and one on each of our bedside lamps.
It's a heck of a lot easier to just reach out and tap the lamps than to
have to stretch and reach up under the lampshades to twist the typical
socket switch knob. And, they provide four levels of lamp brightness
from an ordinary bulb.
I might add that after I installed those switches about 15 years ago I
learned the hard way that I had to install fuse holders and 2 amp fast
blow fuses in those lamps because when a lamp bulb burned out there was
sometimes a "tungsten arc" which drew a surge of current large enough to
blow out the touch switch's electronics. If that happens now I only have
to replace a 20 cent fuse along with the lamp bulb.
SWMBO and I were sitting on the sofa last night watching the election
returns when the lamp next to me turned off. I thought WTF? and touched
the lamp which turned it on again. I went back to watching TV when a few
minutes later the lamp turned off again.
I figured maybe the lamp bulb had somehow gotten loose in its socket and
stood up to reach down from the top to tighten it.
When I looked down I saw a ladybug crawling around near the lamp socket.
A few ladybugs appear in our home every fall, seeking warmth I guess.
I stood there and watched as the ladybug crawled up the side of the lamp
socket shell and turned to walk around the neck of the bulb.
The moment its legs touched both the lamp socket shell and the side of
the bulb's screw base the light went out.
Mystery solved. The bug was creating a connection between the lamp body
and the bulb's base (Which was connected to one side or the other of the
120 volt line). That connection drew enough current to make the touch
switch think someone had touched the lamp and drawn enough capacitive
current to activate the touch switch.
Who woulda thought it? I kicked the ladybug outdoors again.
(W1BSV + Brass Rat '57 EE)
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