62 August 2016
READER - TO - READER TECHFORUM
All questions AND answers are submitted by Nuts &
Volts readers and are intended to promote the exchange
of ideas and provide assistance for solving technical
problems. All submissions are subject to editing and will
be published on a space available basis if deemed suitable
by the publisher. Answers are submitted by readers and
NO GUARANTEES WHATSOEVER are made by the
publisher. The implementation of any answer printed in
this column may require varying degrees of technical
experience and should only be attempted by qualified
Always use common sense and good judgment!
My old billfold was worn out
over the years. I planned to retire it
when I noticed in back was a coil of
10 revolutions ( 6 cm x 4. 8 cm) with
a capacitor marked 47 soldered to
the ends, welded in plastic, the size
of a credit card. I had never noticed
this. Could it be a security feature to
prevent devices from getting to my
credit card? How would it function?
Just curious. A picture of it is shown
#8161 Christian Bock
The lights on my boat trailer work
erratically. Sometimes they work fine
(turn signals, brakes, and running
lights); other times, when I press the
brake pedal, only the right turn light
comes on and all the running lights
go out! Short of tearing it all out and
re-wiring from scratch, any tips on
how to locate the fault and fix it?
#8162 Craig Priolo
Saint Louis, MO
Is It Dumb To Have A Smart TV?
Is it possible (or even necessary)
to try to protect my "Smart" TV from
hackers? If so, what are the issues and
where is the best place to start?
#8163 Maurice Scalf
How Long Is 9 Volts?
Is there a simple way to
determine how long a given circuit
will run on a standard 9V battery?
#8164 Janet Patel
I want to extend my home alarm
system to my garden shed. The shed
has power but no simple way to get
wire to it from the house. Is there a
DIY wireless method to try?
#8165 Woodrow Young
I would like to add a "rain
detector" to my sprinkler system
that would automatically disable the
sprinklers. The system uses an oldstyle mechanical "dumb" timer. How
about a simple circuit to do the job?
#8166 Gary Hunt
It has fallen to me to teach a
short course on electronics for a
summer camp program near our
home. I would welcome suggestions
for curriculum! The kids are ages 8-12.
#8167 Levi Coughlin
[#5162 - May 2016]
Data Transfer Dilemma
I am a mechanical engineering
consultant by profession. I design the
mechanical and hardware/software for
my client‘s ideas and projects. I then
3D print the mechanical components,
fabricate the PCBs, put everything
together, and provide my clients with
working production-intent prototypes.
One of my elderly friends came to
me with an antiquated product called
“The Electronic Rolodex 128k.” He
asked me how he could get the data
onto his computer because the LCD
on this device is starting to fail and he
is no longer able to read the names
and phone numbers. I dabble enough
in this area where I said that I am very
capable of figuring this out. So, I took
on the challenge.
The only data I/O on the device
is an IR transmitter on the left side
and an IR receiver on the right. There
are NO serial ports or any other
connectors that would enable me to
connect to a computer. The purpose
of the left and right transmitter and
receiver is so that if you have two
identical devices, you can transmit the
data from one device (on the right) to
the other device (on the left).
I borrowed an IR to USB adapter
from a friend and opened up a
Tera Term window. I also used my
signal analyzer to determine the
appropriate baud rate (4800). I can
see the data reception and it seems
that I am receiving complete garbage
characters. I have played with my