cost me time and money?
#10136 Erik Prichard
Ft Wayne, IN
Where Does a Kid Start?
My 10 year old wants to start
building circuits. What's a good
resource for easy, safe, one hour
projects for the younger set?
#10137 Judy Boyer
Surplus Parts for Amps
I'm just getting into guitar
amplifiers, and I'm having a hard time
finding parts — tubes, transformers,
and high-voltage capacitors that are
affordable. What are the best surplus
sources, short of taking apart old
#10138 Steven Sewal
Convert USB Webcam into
Analog Video Source
Used USB webcams are a dollar a
dozen these days — much cheaper
than native analog-out cameras (i.e.,
"security" cams). Is it possible or
feasible to convert the USB cams to
analog out? I presume it depends on
the video chip used in the webcam —
whether it has USB integrated or if
that's a function of the small PCB on
which it's attached. Any pointers,
tips, advice, etc., would be greatly
#10139 Dave T.
Analog vs. Digital Meter
I have an old Triplett analog
multimeter and a new, no-name digital
multimeter. A friend told me that, even
though I can read out voltage to the
second decimal place, my old Triplett
is more accurate. I'm confused about
the accuracy/precision difference.
Can you clarify?
#101310 Katy Aricanli
Save a Light
I'm constantly replacing flashlights
because of swollen D cells that
expand and get stuck in the flashlight
barrel.Is there some way to remove
the cells without ruining the flashlight
or splattering battery gunk all over?
#101311 Mitchel Westervelt
[#8135 - August 2013]
Circuit Simulation Program
I’m looking for a circuit simulation
program that is inexpensive and easy
for a novice to learn. I’m mostly
interested in analog circuits, but I do
dabble with digital from time to time. I
want to be able to change component
values and analyze circuit behavior.
This is for my own enjoyment and
education, not for professional use.
Can someone recommend a program
they are using or have prior experience
Here's a nice free circuit simulator:
Linear Technology makes a
nice free SPICE program for when
you graduate to more advanced
design methodologies ( www.linear.
To further your education, Digilent
has some nice online instruction for
For digital, try:
As a side note, as to textbooks,
I'm impressed by:
Unfortunately, it’s a bit spendy.
Here’s a site on basic car audio
electronics which is very engaging:
www.bcae1.com/. This one is geared
towards the car audio enthusiast who
wants to learn about and repair his
[#9132 - September 2013]
I've hit the performance wall with
my Arduino processor. I'm using the
standard development environment
and the latest version of the cards from
SparkFun. Where do I go from here?
#1 There are a few options for
higher performance processors that
are moderately compatible with basic
Arduinos. My personal favorite is the
Maple from Leaflabs.com. Some
others are the Arduino Due, and the
chipKIT boards from Digilent.
Unfortunately, all of these boards
run at 3.3V which often means
changes to external hardware are
needed. The Maple and chipKIT
boards have several 5V input compatible digital pins, and 5V analog input is
possible using two external resistors.
All three boards will require some
modification to anything but the most
basic code. The Maple will require the
most changes, but also has the best
access to hardware features (timers,
high speed ADC, etc.) due to those
changes. The Due will require the
fewest changes, and has the best
support for standard libraries. The
Maple and Due have the best
documentation. If you like the look of
these boards, make sure to check that
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October 2013 79