I am looking to buy or get enough
tips to design and build a device to do
service adjustments on old style
floppy drives that are used in music
keyboards. To run analysis and adjustment software, I have to remove the
drive from the keyboard and connect
it to a computer. But, the new computers don't have floppy connectors
any more. The best device would have
a floppy drive 34 pin connector on
one end, a USB plug on the other,
and some controller in the middle. The
current USB external floppy drives are
quite different from anything I could
use for this project.
#6101 Timothy Edwards
San Diego, CA
AC Motor Control
I'm building an alt-az antenna
rotor controller from scratch, but I'm
having trouble with the circuit for
controlling the AC motor in the
RadioShack rotator. I've tried using a
TRIAC with little success. I believe
they are my answer but I don't understand how to use them. What I need is
a circuit that will accept one direction
bit and one enable bit that will control
a motor’s direction of spin. The
original controller acheived this by
feeding one or the other non-neutral
leads of the motor with ~22V AC; the
third lead is common neutral.
#6102 Matt Williamson
Quartz Cookoo Clock
My quartz cookoo clock has a
photodiode to turn off the clock at
night, but I want it to work at night.
Can I just remove the photodiode?
#6103 Doug Cardona
Rincon, Puerto Rico
78 June 2010
I want to set up a home driveway
sensor similar to a traffic light actuator,
by using a single wire loop in the
pavement that senses vehicles
by changing the frequency of an
oscillator. I need to know how it works
and how to build it.
Vacuum Cleaner Soft Start
I have a Hoover EmPower vacuum
cleaner that causes the breakers in my
home to trip almost every time I first
power it on. After a few minutes of
use, I can turn the machine off and
back on with no problem. I am
thinking that the initial inrush current
is too much for the breakers (they are
GFCI protected). Does anyone know
of some sort of soft start circuit or any
other trick that may help?
I am buying my wife a car, but she
will not get the garage. So, I agreed to
buy her a remote start. I have looked
around for one with a clock that will
start the car every weekday. So far, no
luck. I’m thinking one could program a
PIC to start the car like at 8: 30 am for
15 minutes, except Saturday and
Sunday. Of course, with an override
switch for vacations. Any ideas?
#6106 Michael McKenna
RS-232 To Audio and Back
I have puppets which I can
control with a servo controller board
attached to the serial port of the
computer. I want to record the serial
out to audio, burn a CD, and then play
the audio from the CD and send the
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. Questions are subject to
editing and will be published on a
space available basis if deemed suitable
by the publisher. Answers are submitted
output to the servo controller board,
as though it were coming from the
serial port of the computer. Anyone
have an idea or could help design a
hardware solution to this need?
#6107 George Wood
Noise Suppression in PIC Projects
We develop products with PIC
tech, but are unable to beat the noise.
Can anybody suggest a solution?
#6108 Suresh Naidu
What is the least expensive system to use to program a PIC16F876A?
I got one as a sample from Microchip;
now I don't know what to use to
talk to it.
[#2101 - February 2010]
Motion Sensing Faucet
I want to create a motion sensing
electronic flow faucet. The solenoid
valve is normally closed with an
operating voltage of 24V.
I'm new to this hobby, so I'm not
sure where to start as far as the circuit
design goes. I thought of purchasing
an electronic light switch and
modifying it to trip the solenoid valve,
but the switches are expensive.
#1 Harbor Freight Tools (www.har
borfreight.com) has an inexpensive
($10) proximity detector nightlight
(part number 95276-1AFH) which can
be modified. Remove the LED light
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 individuals.
Always use common sense and good