neighbor might be using X10 too. If his
house is close enough and on the
same pole transformer, you could
receive his signals. Just change to a
house/unit code that he is not using.
#2 I don't have the total solution,
but an idea to start with. Rather than
designing the wireless transmitter
/receiver portion, one pre-existing
solution you can piggyback off of is a
wireless doorbell system you can
get at the hardware store for less
than $20. You can easily test if it will
transmit through the floors.
You can replace the transmitter
(doorbell button) battery with a cheap
power brick to avoid changing
batteries. You also need it for the rest
of the circuitry to sense the air handler
state and fire a relay to close the
Then, you tap into the circuitry of
the receiver/ringer to get the ringing
signal to then pulse a relay circuit to
start/stop the fan.
I have done something similar,
and having a reliable wireless system
to start with was boon to the project.
#2 The simplest solution would
be to have a 'normal' elapsed time
meter that you then read and
subtract from actual elapsed time.
That's not very user friendly,
though, so I'd say get a 12 VDC
'running time' meter (do a Google
search for 'elapsed time meter' and
you should have NO problem
there) and connect it through the
NC contacts on a 120 VAC relay to
a 12V battery. Plug the coil of the
120V relay into any handy outlet.
Keep the battery charged any way
When the power is on, the NC
contacts will be open, turning the
running time meter off.
When power goes off, the NC
contacts close, making the meter run.
For protection, I
sprayed a couple
of coats of a
overcoat on the
box after the
transfer lettering is
to find, but a good
source is Tower
Hobbies at www.
Search for "dry transfer;" they
offer sheets in a wide variety of colors,
sizes, and fonts.
(Be aware that letters and
numbers usually come on separate
Fort Collins, CO
#3 When I was working, we had an
APC UPS RM1500 that came with
the software and cable to be able to
interrogate it for its logs. It kept that
kind of info for power outages and
also surges and sags.
It may work for you.
[#11097 - November 2009]
Power Outage Monitor
From time to time, I experience
power outages when I am not at
home. I would like to either build or
purchase a device which connects to
the AC power line and begins timing
when the AC power drops and stops
timing when the AC power is restored.
The readout must indicate the time
elapsed during the outage.
[#11098 - November 2009]
Can someone recommend the
best way to put professional-looking
text labels on a project enclosure, at a
hobbyist price point? I've been using
Brother P-Touch labels; while cheap,
they don't have the visual impact that
I'd like to have and don't work well in
#2 I had this same problem with my
mistralXG project (see N&V Feb/Mar
2009). After the article was published,
I found a suitable Hammond case to
use as an enclosure, but didn't want to
resort to simple labels. I also wanted
to add a logo to the case. After
examining several alternatives — all
too expensive — I found some vinyl
printer stock that did the job. The vinyl
has a special coating that takes inkjet
ink very well and has a paper backing
that reveals a sticky side when peeled
off. The results were better than I
hoped (Photo 2). You can see the
results at www.grapevyne.com/pic.
projects. I found a supplier on eBay
who sold me a small pack ( 10 sheets
or so) for a few dollars.
#1 I like simple solutions to
problems. I suggest that you obtain a
common electric clock — the old-fashioned kind that contains a synchronous motor. Set the clock to the
time of day. If power fails, the clock
will lose time. Subtract the time indicated from the current value to obtain
the duration of the power outage.
80 March 2010
#1 I used inexpensive dry transfer
(rub-off) letters for a recent project,
and was happy with the results
shown in Photo 1.
I suggest you use masking tape
to align the letters. Use a dull pencil
to gently transfer every corner of
each letter to your box; then press
harder through a paper burnishing
sheet to lock the letters down if you
are happy with the results (or, use a
hobby knife to gently scrape a letter
off if you need to make a change).