Continued from Page 55
IN MEMORIAM continued
I read your notice of the death of
TJ Byers with deep regret. His column
was one of the most enjoyable parts of
your magazine for me for years. His
work was always informative, well-researched, and easily readable, a tough
combination to achieve.
I remember telling myself over the
last couple of months that I ought to
send him an email thanking him for all
his work and to let him know how much
I enjoyed his column. Unfortunately,
other things kept popping up. I put off
writing, and never sent the email. I only
hope he knew how much his work was
appreciated by all of his readers.
My condolences to all on your staff
who knew and worked with him.
memory. However, the suggested
electret preamp circuit of Figure 5 will,
I am quite sure, output a constant 0 volts
DC and AC at the op-amp outputs. The
10K resistors from each of the two
op-amp non-inverting inputs should be
connected to the positive terminal of
the 47 µF capacitor (AC ground at
+ 2.5V), not DC ground. A drawing
It is with great sadness that I learned
of the passing of Mr. Byers. I enjoyed
his Q&A column immensely. In fact, I
always looked forward to reading his
column first when my new Nuts & Volts
magazine arrived in my mailbox.
nificantly less friction. I think that you
would find that an Escap motor with a
gear box would, indeed, have a significant amount of friction, if not as much
as the servos that you used. Indeed, any
gear train will have high levels of friction, backlash, or both. I have written
an article on techniques for coping with
friction and backlash; it is at www.
friction.html. Nothing in there is new,
I've just summarized the techniques that
have found widespread use. Thanks
again for the excellent article.
BOT COLUMN TO THE
I just read the Personal Robotics
article in the Dec. 2006 Nuts & Volts
magazine. You can tell your editors that
it sold at least one copy that would have
otherwise stayed on the shelf.
I teach control systems to engineers,
and have wanted to build an inverted
pendulum demonstrator, but I couldn't
think of a good way to implement the
mechanical design — thanks to Phil
Davis, that problem is now solved.
I wanted to comment on something in his article. Toward the end, Phil
mentions the high friction in the servos,
and notes that an Escap motor has sig-
KEEP ‘CONTROL’ COMING
Just a quick note to say that I
appreciate the 'Control your World'
series by Michael Simpson and hope
to see more of his articles in upcoming
issues of N&V.
My condolences to the staff and
readers of N&V.
TJ was my personal technical
assistant, and when the emails stopped,
I wondered why.
His impact to the enthusiast was
vast. His wisdom was great.
Thank you, TJ, for all. You will be
Wavpro Lighting, Inc.
Sorry to learn about TJ Byers. His
was always the first to read column. He
also came up with a couple of circuits
I needed. I miss Fuzzball, too.
In regards to the February Q&A, a
very simple, nicely linear sawtooth
generator can be built from any garbage
op-amp and a few discrete parts.
The circuit in www.repairfaq.org/
sam/ sfpidrv1.gif has such a circuit in the
lower left (which also does a triangle
wave). This was designed for a specific
purpose but can easily be modified.
Sorry to hear about TJ Byers
passing. I’ve read his articles for many
years and was impressed with his work.
Anonymous via email
I will certainly miss seeing the
byline of the prolific TJ Byers. For me,
his name was the most recognizable in
your fine publication. I may have seen
it as far back as the 50s. What a lot he
created, for years and per issue!
On a different note, perhaps the
following suggested reader feedback will
help avoid a pinned-at-zero output
iNterface Your iPod (Feb 07, p54-
56) was just what I was looking for to
complete a project requiring analog
March 2007 95