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Animal-friendly Mousetrap - This mousetrap is built around a
PIC12F683 and uses an infrared transmissive optical sensor that is modulated
at a frequency of 38 kHz, so that it isn’t affected by the ambient
light..….must register on this site.... [Published in Elecktor July/August
2010] |
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Bat - Here’s a novel way of listening to bats over the Summer. Put
the receiver — powered by four AA (R6) cells — on a window-ledge, for
example, preferably aiming the ultrasonic detector towards an outdoor light
or some trees. Run out a few metres of cable so as to install the small
loudspeaker inside the house....must register on this site.... [Published in
Elecktor July/August 2010] |
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Bat detector - The Simple Bat Detector is a frequency division
type device. Frequency division type detectors allow you to hear ultrasonic
sound by digitally scaling the frequency down into the human hearing
range....Tony Messina - Las Vegas, NV] |
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Bat Detector - Circuits modified by Herb Guenther from schematic by Chris
Englund c1999 (electronic circuit added 4/05) |
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Bat Detector Circuit - Ever since my grade school years I've been fascinated
with the way a bat uses ultrasound to "see" in the dark. The bat's echolocation skills
let it avoid small obstacles, and even catch insects, while in flight. I learned that
bats are, ultrasonically speaking, very loud --- so loud, that some of.... [Tony
Messina- Las Vegs, NM] |
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Bat Detector Circuit - Basic tests with a variety of salvaged electret
microphones all showed good response to 50kHz and beyond, the smaller the unit the
better the response. My tests indicate that a small electret microphone has at least
some response to 100kHz and that this response is reasonably "flat" to at least
50kHz.... [Chris Eve's design] |
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Bat detector microphone pre-Amplifiers - The microphone pre-amplifier has
the job of amplifying and conditioning the signal coming from the microphone. In case
of an electret microphone, the amplifier must have a gain that increases with
frequency to compensate for the low sensitivity of the microphone for high
frequencies. Also the low frequency part must be filtered out. In case of a piezo
transducer,(circuit added 6/07) |
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Bat detector old - (electronic design added 11/06) |
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Build a Simple Bat Detector - Ever since my grade school years I've been
fascinated with the way a bat uses ultrasound to "see" in the dark. The bat's
echolocation skills let it avoid small obstacles, and even catch insects, while in
flight. I learned....(electronic design added 7/08) |
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Deer Repellent (techlib) - Here is a simple sensor which can detect the
seismic vibrations caused by a person or large animal walking nearby. A representative
application for the sensor is a deer repellent for the vegetable garden…....
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Elec Roach Motel - Using a PIC for this device provides a lot of useful
functionality.The timing for the power pulse to the inductor is critical to getting
the best Zap from your nine volt battery. The longer the current is on, the
higher the voltage. Once the inductor reaches saturation, however, you are just
waisting power.….(electronic schematic added 08/08) [Luhan Monat - Mesa Arizona] |
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Hap Tells His Backyard Varmints to Hit the Road - Gadget Freak Case #93:
Tired of torn-up flower beds, Hap took matters into his own hands by combining a
sprinkler and wireless driveway alert system. To allow enough time for the sprinkler
valve to open, build pressure, and activate the sprinkler head,.…. (added 05/06/07)
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Insect Repellant - The idea for this project may have come to me in a flash
of inspiration, and its a very simple way to check if a fuse has blown without
removing it from its holder…. [Circuit by Andy Collison] |
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Mosquito Repellant - very simple and easy to assemble mosquito repellant
using two transistors and handy components...... |
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Mosquito Repeller - This circuit produces a tone above the human audible
range and this is supposed to keep the mosquitoes away. You need a piezo diaphragm
that will respond to 15kHz and these are very difficult to find. |
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Parasite zapper - This page tells you how to make a Hulda Clark-style
"Parasite Zapper". This is a simpler and more efficient version that works just
like the original, but the battery lasts much longer. We make no therapeutic claims
for this device. It is for experimental purposes only.... |
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Ultrasonic Pest Repellent - It is well know that pests like rats, mice etc
are repelled by ultrasonic frequency in the range of 30 kHz to 50 kHz. Human beings
can’t hear these high-frequency sounds. Unfortunately, all pests do not react at the
same ultrasonic frequency. While some pests get repelled at 35 kHz, some others get
repelled at 38 to 40 kHz. Thus to increase the effectiveness, …. (added 10/05)
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Ultrasonic Pest Repellent (radioland) - Rats, mice are repelled by
ultrasonic frequency in the range of 30 kHz to 50 kHz (circuit added 11/06)
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Ultrasonic Pest Repeller - These emit noise to confuse or agitate insects or
animals. This is one of the better and more popular brands. It emits bursts of
pulses at different frequencies. I did not find any spider webs inside this unit…
[Reverse engineered schematic by Stepan Novotill] |
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