In this column, Russ answers questions about
all aspects of electronics, including computer
hardware, software, circuits, electronic theory,
troubleshooting, and anything else of interest to
the hobbyist. Feel free to participate with your
questions, comments, or suggestions. Send all
questions and comments to: Q&A@nutsvolts.com
20 November 2013
■ WITH RUSSELL KINCAID Q & A
Post comments on this article and find any associated files
and/or downloads at www.nutsvolts.com/index.php?/
• Jacob’s Ladder Redux
• Video Monitor Alarm
• Robot Communication
More On the
QI have nothing but good news! First, I want to thank Mr. Carlson for his response and advice;
slowing the frequency down made all
the difference in the world. Second, I
would like to thank you! Without
your help, Russ, I know I would not
have had this much success.
I have not changed the last
revision of the circuit I previously
submitted. I reengineered the
construction of the electrodes
making them easier to adjust, and
fine-tuned the oscillator. Now, I’m
getting a spark to gap 1/8” and climb
a 10” set of electrodes ending at a
final gap of 7/8”.
There are two coils that I have
been working with — both 12V. The
first is a smaller twin cylinder type
coil; the second is an old can type
automobile coil. In my opinion, the
smaller coil actually does a better
job. It gives a longer more active
spark, but it is not as bright.
I want to build a switch circuit.
Push the button and it will turn on
for 15-20 seconds or whatever, and
then turn off. I know I can do this but
I have a concern. Additional circuitry
will undoubtedly consume more
My thoughts are to upgrade to
another power supply. Another 12V
with slightly higher amperage: 13.8V
at 5A or 15V at 8.4A.
I’m not sure if more voltage,
more amperage, or if both are the
way to go. I don’t want to overdo it.
As the circuit stands now, from a
12V 5A supply it delivers 9. 8 volts to
the coil — a 2. 2 volt loss.
I do not know how to check the
current consumption on this circuit.
There are several stats I would like to
check, but I need to read up on how.
The hex Schmitt trigger has an
18 volt max voltage limit, and the
two aluminum electrolytic capacitors
are rated at 16V. The other
components exceed these voltage
■ FIGURE 1.