LCD TV Displays
I have a Casio portable color LCD
TV (handheld) that has been made
obsolete by the new digital signals.
I would like to use the display in
an upcoming project.
Can anyone direct me to where I
could find information on driving
color displays with a microprocessor?
#3101 TJ Treinen
Convert Old Record
Player To Record To USB
I have experience programming,
soldering small projects, and wiring.
I've built my own computer from
parts. I have a stack of records from
the ‘50s, ‘60s, and ‘70s, and two
record players (never tossed the old
electronics). I saw a device in a
store that would record your records
to USB. Can't I build my own? Any
78 March 2010
Experiments With An AC
I have been experimenting with a
10,000 watt AC alternator. This is the
kind that is usually called a generator
that outputs 110/220 VAC for use as a
backup power source. Although I have
had a good deal of experience with
electricity and electronics, I have yet
to find a good explanation of how this
type of alternator actually works.
Every source I can find on alternators
deals with automotive alternators
which I assume are similar.
I have an application where I am
using the variable speed from the gas
engine that turns the alternator to
create a variable AC voltage output. I
know an alternator of this type has no
permanent magnet so it needs to get
up to some RPM before it generates
ANY voltage at all. On mine, this
kicks in somewhere between 35 and
50 volts AC.
Can someone explain how
this type of AC power alternator
actually works and do you think it is
possible to excite the fields externally
so the output voltage kicks in more
consistently at low RPM?
#3103 Greg McMurry
Pacific Palisades, CA
DC Electric Motor
How does one find the wattage of
a 24 VDC motor that has no name
plate? I want to purchase a speed
control for my electric bike, but they
all want to know the wattage of the
What is the difference between
an ordinary light dimmer and a ceiling
fan speed controller? They look the
same except one is twice the price.
#3105 Terry Stine
PIC Generated Voltage
How can I use a PIC controller to
generate the required voltage in a
DC/DC converter with an LCD display
or USB communication with a laptop?
I'm looking for an anemometer
circuit using the cooling effect on transistors. I found some on the Internet
but they typically only measure low
(< 2 mph) wind speeds. A circuit with
an analog output I can interface to a
microcontroller would be great as I
plan to add other sensors. Mechanical
All questions AND answers are submitted
by Nuts & Volts readers and are intended
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problems. Questions are subject
to editing and will be published on a
space available basis if deemed suitable
by the publisher. Answers are submitted
anemometers need to be calibrated
which I'd like to avoid (and I’d rather
build a circuit anyway).
I need an anemometer to
measure "normal" wind speeds (up
to maybe 50 mph). I'd like to install
a wind mill next year to assist in
powering my house but I want to log
the wind speeds and frequency to
determine if it's worthwhile installing
Stereo Headphone Volume
Control And Left-Right Reversing
I want to build a stereo headphone control box for a home recording studio monitoring setup. It can be
passive or active, but if it is active, it
must have high quality circuitry, as
should all the other components. It
needs to have left and right channel
volume controls, plus a low-noise
switch (leaf switch?) to reverse the
left and right channels so that I can
quickly change the signals between
left and right channels without
removing the headphones. Can anyone offer a schematic and parts list?
[#10092 - October 2009]
I need a parts list and schematic to
create flashing lights on small scale
emergency vehicles to be used on a
slot car racing layout.
#1 Figure 1 is a schematic using the
venerable NE555 timer to simulate
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