Continued from page 8
are X band but there are some in the K
regions also. Even 10 years ago, when I
was responsible for the maintenance and
repair of the door openers at the hospital where I work, they were all radar. I
would also question the reliability of PIR
detectors used to scan outside areas as
they are affected by factors such as wind
and other weather phenomena. On the
other hand, the Doppler shift radar
detectors work well in this application.
By the way, love your magazine!
You have come up with a great balance
between the old analog and digital discreet designs and the new PIC projects.
I am an old discreet designer/builder
who is learning to love the new PICs,
especially the PICAXE due to its ease
of programming and low cost. Keep up
the good work!
PUT A (HEAT) TAPE ON IT
About thawing frozen pipes ...
there is a better way to thaw them and
to keep them from freezing again. There
is a product available called heat tape.
It looks like a roll of 12 ga romex wire
except that it’s a heating element with
a temperature sensor in it and a plug
or direct connect, depending on the
model purchased. This wire is wrapped
around the exposed piping and then
covered with an insulation sleeve and
connected to standard power.
When the enclosed sensor detects
falling temps in the correct range, it starts
heating the pipes to prevent freezing;
the insulating sleeve keeps the heat in
and helps keep the energy use low. I
have used these wraps with great
success. It’s a lot less expensive than
paying to have the frozen pipes thawed
and the burst pipes replaced, not to
mention the water damage after the
pipes burst. By the way, if you are a
renter, when you leave you can take the
wire with you; if it’s a plug-in type, it’s
not considered a permanent item so you
don’t have to leave it if your landlord
won’t pay for it.
The following website gives an
excellent tutorial on the proper use and
installation of pipe heat tape including
several safety precautions: www.mygreat
October 2007 93