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94 July 2009
Wind Speed Controller
I need a circuit for several
applications that need to be switched
on/off (open/closed) by relay, depending on wind speed.
The circuit needs to be able to set
a minimum wind speed to activate and
a maximum wind speed to deactivate.
Also, it needs variable activate and
deactivate timers (about 30 seconds to
five minutes) so that wind gusts will
not activate/deactivate the circuit too
There are several stand-alone wind
speed devices on the market, as well as
included in complete weather stations.
They all seem to be wireless in nature
and talk to some type of receiver
monitor or computer. A stand-alone
"wired" wind speed device to controller
circuit would be preferred.
#7091 Vonn Hockenberger
We have been trying to find a
better way to keep track of thousands
of inventory items we have on campus.
We would like to do this the cheapest
and most effective way. Our budget
right now is not that large. We have
looked at a few applications from
i Tunes App store, but most of them are
web based — "Info already on the web."
I was wondering if RFID chips could do
this sort of thing? We want to put the
serial number, item name, and model
number into either a barcode or chip
that can be stuck to the item. Is the
RFID system able to do this or very
inexpensive barcode software? The
RFID I am talking about uses those little
chips like you find inside a passport.
Simple Low Frequency Transmitter
How would I build a low frequency
(say 512 Hz), battery operated sine
wave transmitter that was small enough
to fit inside 1" PVC pipe? I'm not sure if
a resistor, capacitor, or crystal is the
best; how do you wind a coil antenna
to match the frequency?
#7093 Gordon Eden
I want to build a project using a
BASIC Stamp 2p40 to allow me to reset
pin setters at the bowling alley I work at
from the front desk. I need a way to
interface between the BASIC Stamp
and the pin setters. The reset button is a
24 VAC circuit and I will be connecting
in parallel with the reset switch. I was
thinking about using something like an
opto-isolator but I want to be able to
reset multiple lanes at the same time
and am concerned because the Stamp
can only sink 60 ma/eight pins, and
from what I have seen in opto-isolators,