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|
INFILTEC: How to Build an Inexpensive Seismometer - make seismograph kit
How to Build an Inexpensive Seismometer.
Detailed information on how to build a seismometer
that can detect earthquakes worldwide. This inexpensive
design is based microprocessors and newer chips.
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INTRODUCTION:
Welcome to The Inexpensive Seismometer Project! See
 for latest page updates.
These pages describe my project to build simpler and less expensive amateur seismometers by
using microprocessors and other new chips, such as switched capacitor filters. I have
tried to provide links to much of the excellent information that is already on the web.
And I have tried to fill in some of the gaps in the existing information. For instance:
Where do you get all the hard-to-find parts?
What is the simplest & cheapest system you can build that will still detect 5M quakes in
California and 6M quakes worldwide?
What is the bottom line cost, and how can you cut costs?
I am offering seismic systems based on my designs, and will offer kits if there is demand.
Note that this page does not cover long-period seismometer designs other than the Lehman
because I don't know much about them yet.
Please send me your comments and I will try to incorporate
improvements and corrections into these pages.
PROJECT STATUS: On December 05, 2005 I completed an improved design of my PCB, incorporated
a lower noise amplifier (AD8628), and added a diecast alumimum enclosure for thermal and
electromagnetic shielding. This improved my system noise floor by about 5x. Systems
and kits based on these improvements are now for sale.
QM-1.0 long-period one-axis seismic processor and
schematic and
kit instructions
for long period sensors (like a Lehman),
QM-4.5 short-period one-axis seismic system and
schematic and
kit instructions
for the 4.5 Hz geophone, and
QM-4.5-ADXL103 one-axis strong-motion accelerometer.
My simplified electronics design uses
only 4 chips for the amplifier, 8 pole Bessel filter, 16 bit a/d, and serial output. These
boards are powered by the PC serial port, and they are designed to work with the freeware data
log/display program Amaseis.
Please
,
if you are interested.
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SEISMIC ACTIVITY TODAY:
Latest Worldwide Earthquakes from USGS NEIC in Golden, Colorado.
(text only version)
Red Puma automatic quake location system (very fast, but may be wrong!).
Near Real Time
USGS Seismograms and
Worldwide map and
NY Seismograms and
VA Seismograms
and in helicorder format.
Amateur Seismographic Recordings
of recent earthquakes.
Seismo-Watch sign up to receive email alerts about earthquakes.
USGS: BIGQUAKE, QEDPOST, MTALL sign up to receive email alerts about earthquakes.
Search
Google News Search for earthquake and order by date.
Yahoo News Search of Reuters, Associated Press and other news sources for earthquake.
USGS US Map with clickable quakes.
California and Nevada Map with clickable earthquakes from the past week.
Latest NOAA Tsunami Advisory Bulletin and the
West Coast and Alaska Tsunami Warning Center.
Live
Webcams
of Volcanoes all over the world. Webcam at volcano
Baru in Panama.
Seismosurf
the Internet for Earthquake Data.
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FAQ
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GETTING STARTED:
"Lehman Seismometer" article From the July, 1979 Scientific American Magazine.
This is the classic article that includes the simplest long-period seismometer design.
Here is a better image of the Lehman hardware.
Homebuilt Seismograph FAQ
Here are some improvements on the original Lehman design.
Build Your Own Seismometer - Record earthquakes from all over the world - Andy Loomis.
There is a nice Lehman amplifier and filter design here.
Detailed Plans for a Lehman Seismometer
Very nice mechanical drawings.
Shackleford-Gundersen Seismometer more complicated than Lehman, but
with some advantages.
Redwood City Public Seismic Network
The most comprehensive source of amateur seismic information on the web.
Seismograph – Magnitude Determination and Calibration this article
is about a somewhat different seismograph but it uses the same freeware
Amaseis software that I use. There is a lot of good information here.
Lehman Manual (PDF format) "Instructions for Construction of Lehman Seismometer"
by Kelly Knight - May 2000. Does not include electronics.
Build your own Seismograph Station information from the experts at PSN.
Guidelines for Installing Broadband Seismic Instrumentation
expert guidance, not necessarily for amateurs, but it may give
you some ideas.
Join the
Public Seismic Network Mailing Lists and search their archives.
An Introduction to Earthquakes & Earthquake Hazards online lecture notes by Charles J Ammon of Saint Louis University,
book formatted as 14.5mb pdf file.
How to build your own seismic station by Mauro Mariotti.
Links to amateur seismometers by Kevin Schavee.
Clickable map of amateur seismometer locations.
EPIC's CSM 2002 Student Design Project: Design & Build a Seismometer!
School Seismograph Station at St.-Michael-Gymnasium Monschau, Germany.
An Inexpensive Vertical Seismometer for Classroom Demonstrations.
Seismometer Projects for Kids
Hubbard Scientific Seismograph Model (Earthquake Sensing Kit) Grades: 6 - 12.
Build Your Own Seismograph -includes diagram and parts list.
Building a Seismograph -includes diagram and parts list.
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COMPONENTS
What are the basic components of a seismograph?
BASIC COMPONENTS
Sensor - typically Lehman pendulum assembly with base and cover.
Pickup coil and Magnet.
Preamplifier.
Low pass filter.
Analog-to-digital (A/D) converter.
Computer program for the data storage to disk and real-time "Helicorder" type display.
Computer program for post analysis of data.
I assume that you have a computer and monitor and printer that
can be used for data collection and analysis. Ideally the programs
for data collection can be run in background while the computer
is used for other talks like data analysis.
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ELECTRONICS
I will start with electronics since I think that is
where most folks who want to build their own system bog down.
Most of the seismic circuit designs that I have seen
do not use microprocessors and they use filter designs
that require lots of precision components. They generally have
one amplifier/filter board and another board with A/D
and PC interface. They also use dual power supplies.
I have attempted to make use of some of the recent
advances in low-power, precision chips and mixed signal
microprocessors. My design goal was a single board that did
everything with a minimum number of inexpensive components, and
could be run off a single 9 volt battery for 100 hours
(or no power supply at all!).
Here is my simplified design for Lehman,
geophone, and accelerometer electronics.
It requires a single-ended 5.1v to 16v supply and generates serial (RS-232) data output.
There is no sacrifice in signal processing quality due
to the 8-pole Bessel filter and 16 bit a/d.
My circuit uses only 4 low-power chips:
VOLTAGE REGULATOR AND REFERENCE CHIP -
LP2950ACZ-5.0 Micropower Voltage Regulator provides a 100 ma voltage regulator
and a precision voltage reference. This chip
requires 5.1 volts and 0.1 ma, and has a temperature stability of 20 ppm/C.
A resistor voltage divider is used to create a stable 2.5 volt reference for biasing
the sensor coil so that the electronics can operate from the single 5v supply.
The 20k ohm voltage divider uses about 0.25 ma. Net power requirements: 0.35 ma @ 5v.
The total board power requirement is low enough (~5 ma @ 5 v) so that it can
draw power from the PC serial port. Since the 12 volt PC power from the serial port
is produced by a switching power supply, it is full of spikes, and I could do RC
filtering on it to smooth it out. So far, I have not found this to be necessary.
AMPLIFIER CHIP - To allow my circuit to work with a single-ended 5v supply,
I bias my sensor coil by about 2.5 volts,
and I have a single op amp stage for gain
(~1.2k gain for Lehman and ~2.6k gain for geophones).
So my op amp output is 2.5 volts plus the amplified seismic signal.
This allows me to use a 0-5v 16 bit a/d, where zero signal sensor a/d
output is ~32768. My op amp chip must run off a single 5V supply, have
a rail-to-rail output, low noise level (under 100 nV/\/Hz\ @10 Hz),
high CMRR at 2.5 v (over 80 dB), low offset drift (under 0.5 uV/C)
low offset voltage (under 500uF), and low power operation (under 3 ma).
I came up with these specifications by trying some other chips that
did not work, and comparing them to chips that did work.
For low impedance sensors like geophones I like the
LT1677CN8 Low Noise, Rail-to-Rail Precision Op Amp. It works best with
a source resistance (Rs) less than 400 ohms and possibly up to Rs as high as 8k ohms.
Above that Rs, the data sheet says the noise is significantly higher.
However, this chip seems to work well with
my 9k Lehman coil. The chip requires 5 volts, single supply, 2.85 ma. Specs include
noise ~70 nV/\/Hz\ @10 Hz, CMRR ~109 dB, Offset Drift ~0.2 uV/C, Input Offset Voltage ~60 uV.
For higher impedance sensors I like the
TLC2201CP Low Noise Precision Rail-To-Rail Output Op Amp.
The TLC2201ACP and TLC2201BCP have better guaranteed specs.
This chip requires 5 volts, single supply, 1.5 ma.
Specs include
noise ~30 nV/\/Hz\ @10 Hz, CMRR ~85 dB, Offset Drift ~0.5 uV/C, Input Offset Voltage ~500 uV.
Since the op amp output goes into the switched capacitor filter it
is necessary to suppress any high frequencies that might be mixed by
the switching frequency. I find that an RC filter using a capacitor (Cf)
across the op amp feedback resistor (Rf) works fine if I set the RC filter
cutoff (Fc1) to about 1.5 times the switched capacitor cutoff (Fc2).
For instance, if the Fc2 is 1 Hz for a typical Lehman, then Fc1 should
be 1.5 Hz, and Cf should be chosen so that Fc1= 1.5 Hz = 1/(2*Pi*Cf*Rf).
For 4.5 Hz geophones, I set Fc1 to 4.5 Hz and Fc2 to about 6.8 Hz.
For ADXL105 accelerometers I use the same filtering as I use for
the 4.5 Hz geophones, and I use the on-board op amp rather than a
separate gain op amp.
FILTER CHIP -
MAX7401CPA 8th Order, Lowpass, Bessel, Switched Capacitor Filter
low pass cutoff is configured with one external capacitor. I generally use
a cutoff of 1 Hz for a Lehman and 4.5 Hz for a 4.5 Hz geophone.
This chip requires 5 volts, single supply, 2 ma. The -3 dB filter cutoff (Fc2)
in Hz is determined by Fc2=.380/C where C is the capacitance in ufd.
For example, when C = .380 ufd, then Fc2 = .380/C = 1 Hz. The output
of a switched capacitor must be filtered to remove the switching
noise that peaks at 100 times Fc2 for this chip. I generally use
an RC filter with an Fc3 that is about 1.5 times the chip Fc2. So in the
case of the example of a chip Fc2 of 1 Hz, then R3 and C3 should be chosen
so that Fc3 = 1/(2*Pi*R3*C3) = 1.5 Hz. For 4.5 Hz geophones I set Fc3 to
about 6.8 Hz. For ADXL105 accelerometers I use the same filtering as
I use for the 4.5 Hz geophones.
A/D & PC INTERFACE CHIP -
PIC14000-04/SP Programmable Mixed Signal Controller
programmed with firmware that I wrote to configure IC pins for 16 bit A/D, and for serial output to a PC. This chip requires 5 volts, single supply, 0.5 ma.
PIC 8-bit microprocessors can be programmed in firmware written in languages like
PicBasicPro or
CCS PIC C.
You might be able to use a
Basic Stamp BS1 or BS2 processor
with an external A/D chip in place of the PIC14000. However, these
processors and the a/d chip may use too much power to use the serial
port as a source of power.
PCB LAYOUT AND NOISE REDUCTION -
In order to get 16 good a/d bits, the circuit board must be laid out so
as to minimize noise. All grounds must go to a central terminal
point in a "star" configuration. All chips must have bypass capacitors
on their power pins. In addition, the PIC14000 is programmed so that it goes to
"sleep" during a/d operations to minimize digital noise in the circuit.
SAMPLING RATE -
The 4 MHz PIC14000 can perform 16 bit A/D at about 60 samples per second (SPS) and
these samples can be averaged in software for noise rejection. I have written the firmware
to allow for a dip switch selection of averaging times from 4 SPS to 20 SPS.
SERIAL DATA FORMAT -
Each output sample is an ASCII record terminated by LF and CR. The samples range from
-32767 to +32767. This format can be read by the
AmaSeis
seismic data acquisition program. Output from Amaseis can be further
analyzed by the
WinQuake seismic event viewing software.
PICTURES AND DIAGRAMS OF MY LATEST SYSTEM DESIGNS
(Click on thumbnails below for full screen images)
Short-Period Seismometer (complete system with electronics and sensor)
Infiltec QM-4.5-L15B exterior.
Infiltec QM-4.5-L15B interior.
Infiltec QM-4.5-L15B circuit board, enclosure and
4.5 Hz geophone.
Long-Period Seismometer (partial system with electroncs but no sensor )
Infiltec QM-1.0-3074 Exterior.
Infiltec QM-1.0-3074 Interior.
Infiltec QM-1.0-3074 circuit board, enclosure,
pickup coil and magnet.
Note that the long period QM-1.0 seismometer printed circuit board is identical to the QM-4.5
board except for passive component value changes to reduce the low pass filtering to 1 Hz.
The QM-1.0 is designed to work with a 9k ohm pickup coil and moving magnet.
Here is the QM circuit schematic diagram.
SAMPLE OUTPUT -
How well does this circuit work? Here is the
January 13, 2001 magnitude 7.6 Central American quake,
detected with my
QM-1.0 Lehman from approximately 3,000 km away,
that almost saturates the electronics (+/-32767).
And here is
January 26, 2001
magnitude 8.0 in Southern India, detected from
about ~13,000 km away.
Here is a
January 12, 2002 magnitude 5.7 quake near Bermuda
about 1,300 km away, detected from Virgina with a
QM-4.5 geophone system.
These displays were generated by the WinQuake software.
In general a my long-period Lehman system can detect
+5M quakes in the US and +6M quakes worldwide.
My 4.5 hz geophone system generally does not detect
quakes unless they are within a couple hundred
km.
A/D CONVERTER OPTIONS -
I use a microprocessor ADC to generate the serial data that Amaseis
can process (the input ASCII records looks like +3, -2, +8 .....) but if you are
not a microprocessor guru you can get a PC serial port data aquisition kit from
DataQ. Their
$24.95 DI-194RS Starter Kit is
4-Channel, 10-Bit, ±10V ADC. And the
LEHMAN PICKUP COIL -
One inexpensive source for the small multi-turn coil that
you need for a Lehman seismograph is 110V or 220V relays.
You can take them apart and find small copper coils that
have resistances of 2k to 12k ohm. One inexpensive source for these
relays is
Hosfelt Electronics. You generally need a screwdriver
and a small file to release the coil from its mounting.
LEHMAN DAMPING -
If you do not damp the swings of your Lehman boom, then it will be too
responsive at its resonant frequency. Three methods have
been suggested: hydraulic (vane in an oil bath), eddy
current (magnet moving across an aluminum
or copper plate), and electromagnetic (a damping resistor across your pickup
coil). Hydraulic and eddy current damping are describe
in most of the Lehman design web pages.
Sean-Thomas Morrissey
has a detailed description of
electromagnetic damping.
LEHMAN MAGNET
Alnico horseshoe magnets can be obtained from the
Grainger company.
Just search Grainger for "alnico magnet". The size of the magnet
will depend on the size of your coil. You want a magnet
that has just enough clearance around the coil so that
will not touch. The cost is $15 to $19 depending on the
size. Another source is
Edmund Scientific but they seem to be more expensive.
Rare Earth Another possibility is to use the very strong
niobium-iron-boron magnets. These magnets are generally flat but
have multiple poles across the face of the magnet. A
coil moved across these poles should see a varying magnetic
field that would generate a voltage. These magnets may
be significantly less expensive than the alnico
horseshoes. Some sources are Rare-Earth Magnets,
Force Field and
Hamilton Core Drill Bits. Note that rare earth magnets can be salvaged
from hard drives.
http://www.rare-earth-magnets.com/
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COST
How much is it going to cost you to build a Lehman long-period seismograph? It depends on
how much you want to build and how much you want to buy.
PENDULUM - cost of parts from Home Depot (under construction)
2 flanges for bolting the assembly to a base @ $4.00 from Home Depot #xxxx
2 3/4" black pipe T fittings @ $2.00 from Home Depot #xxxx
2 3/4" black pipe 90 degree elbows @ $2.00 from Home Depot #xxxx
1 3/4" black pipe union @ $1.00 from Home Depot #xxxx
4 3/4" black pipe nipples 2" long @ $4.00 from Home Depot #xxxx
2 3/4" black pipe nipples 6" long @ $2.00 from Home Depot #xxxx
1 3/4" black pipe nipple 5" long @ $1.00 from Home Depot #xxxx
1 10"x24" laminated shelf board for base @ $4.00 from Home Depot #xxxx
3 3"x1/4" screws for leveling @ $1.00 at Home Depot #xxxx
3 cap nuts for 1/4" bolt @ $1.00 at Home Depot #xxxx
1 #8 steel guitar string @ $1.00 at music store
1 5 lb lead weight @ $5.00 from
McMaster Carr #9031K1
1 24" x 3/8" coarse threaded steel rod @ $4.00 from Home Depot #xxxx
4 steel nuts for 3/8" coarse thread rod @ $1.00 from Home Depot #xxxx
1 1/4" steel ball bearing @ $1.00 from Home Depot #xxxx
1 cover made of old cardboard boxes @ $0.00
--------------
Total $34
OPTION 1 - current state-of-the-art
1) Build Pendulum $30 from Home Depot etc.
2) Buy Pickup coil $15 from
Larry Cochrane
3) Buy Magnet $20 from
Larry Cochrane
4) Buy Preamp/filter/power supply: $115 from
Larry Cochrane
5) Buy A/D board : 12 bit with WWV time correct $195 from
Larry Cochrane
6) Buy Data collection and display software: SDR @ $00 from Larry Cochrane
7) Buy Data analysis software: WinQuake @ $35 from
Larry Cochrane
--------------
Total $410 for 12 bit, $480 for 16 bit
Advantages: proven technology, compatible with many other users, quick
Disadvantages: highest cost, no chance to do electronic construction
OPTION 2 - do most of it yourself
1) Build Pendulum $30 from Home Depot etc.
2) Buy Pickup coil and magnet from
Larry Cochrane @ $35
3) Build Preamp/filter/power @ $30 built from
Andy Loomis design
4) Buy A/D converter:
12 bit DataQ @ $99
5) Buy Time correction: PC software
Rightime @ $35 and
AboutTime @ $00
6) Download Data collection:
AmaSeis
PC software @ $00
7) Buy Data analyis:
Winquake PC software @ $35
--------------
Total $254
Advantages: lower cost
Disadvantages: electronic design/construction required, most time consuming
OPTION 3 - Proposed new Infiltec system design (estimated prices)
1) Build Pendulum $30 built from Home Depot etc.
2) Buy Coil/magnet/preamp/filter/16 bit adc/power @ $149? from Infiltec
3) Buy Time correction: PC software
Rightime @ $35
and AboutTime @ $00
4) Download Data collection: PC software
AmaSeis @ $00
5) Buy Data analyis: PC software
Winquake @ $35
--------------
Total $249?
Advantages: low cost, easy to get running
Disadvantages: new design that is not as field tested as Cochrane's
Note: If the electronics were in kit form the total price might be closer to $200.
OTHER OPTIONS
There are other options, especially for A/D and software, that I have
not covered above, but I think that the three options above outline the
general state-of-the-art as of the beginning of 2001. Let me know
if you think I am wrong, or if some new products become available.
I plan to add a similar cost analysis for a
short-period geophone system,
and a strong-motion accelerometer system.
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PENDULUM LOCATION AND POSITIONING
In order to use most seismic software you will
have to know your site latitude and longitude.
There are many web sites that can compute
this from your street address. I used
Eagle Geocode
to compute mine.
BTW, once you know your location you can watch
for satellite phenomena like
Iridium Flares.
In order to point your seismograph you need to use a
compass. Most of us folks on the East Coast of the US align
our seismographs E-W in order to be most sensitive to
California and Asian quakes. By "align" I mean that the swing
direction of the pendulum is pointed that way.
Of course you may want to correct
for the fact that your compass does not point to "true
North" because of
magnetic declination. For instance, I am in Northern
Virginia where the declination correction is -9 degrees. So true North for
me is actually 9 degrees off compass North.
To correct for declination you must rotate your compass counterclockwise
to correct on the East Coast and clockwise on the West Coast (where the
declination correction is positive.) This is not a big correction for me,
but it could be over 20 degrees if you are in the extreme NW or NE US. Even
that does not make a big difference with seismometer sensitivity since
the low frequency teleseismic quakes are not highly directional.
Here is more information on finding
True North from
the sun's position.
My system sits on the basement slab of a VA office building about
100 feet from an continuously operating HVAC unit, with a major
road about 100 ft on one side, and a McDonalds drive through about
50 ft away on the other. During the day the record shows many spikes
similar to what happens when someone walks near the pendulum and
deforms the slab. I get some pretty quiet data in the middle of the night
when the Big Macs go home.
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Introduction
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FAQ
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TIME SYNCHRONIZATION
You will need to get an accurate time reference to
Coordinated Universal Time (UTC)
(Greenwich England time without daylight saving time) since you want
to know the arrival time of quakes within a second
of UTC. Some folks hook their electronics to GPS or WWV radio
systems but I am too cheap for that. I looked for
some way to make my PC clock accurate to within
a fraction of a second per week instead of its usual
several seconds per hour of error. Here is what I
came up with:
1. Go to the Windows control panel under "Date/Time" and set your
computer to GMT with no daylight savings time.
Right now (winter) this is 5 hrs earlier than Eastern Time. It is not
too much trouble to work with a PC set to this time.
2. Go to
AboutTime
and download the free program "About Time 4.8". This Windows program
finds the reference time on the web and resets your
computer clock to it. It even corrects for the travel
time of the web packets. Set your clock within a
few ms of UT with this program. If your computer has
a dedicated web connection, you can set AboutTime
to reset the time ever 10 or 15 minutes, and that
keeps your computer clock in synch. However if you
do not have a dedicated web connection, then you want
some way to adjust your internal PC clock to an accuracy
of a fraction of a second per week. Go to step 3 to
find out how to do this.
3. Go to
RighTime
and download the shareware program RITM514.Zip. This program
only works for DOS of Win95-98, not Win2k. It
makes changes in your autoexec bat and each time
you correct your PC clock, it makes the PC clock
error smaller. I have been able to get my data logger
PC to within a fraction of a second per week accuracy.
I have found that you must install this program in
the DOS mode that you get into from the Win95-98
shutdown.
It took me about a week of these corrections to get my PC
time reset accurately. Rightime has a free trial period
that you should use to see if it works for your computer.
I have had success in 3 out of 4 PCs. My AMD Althon 850
does not seem to work with RighTime, so far.
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Introduction
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Today
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Starting
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Components
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Cost
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Location
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FAQ
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SEISMIC DATA PROCESSING SOFTWARE
I found when I started my project in 2000 that most of the
existing seismic data logging software was programmed
to accept data from a few PC a/d boards, and most of the
programs did not accept the ASCII data records that
microprocessors can easily output. However I found one
program that the author was willing to modify to accept
simple ASCII records: the freeware program Amaseis.
Here is all of the seismic software that I am have
heard of that might be of interest to amateur seismologists.
Please send me links to all the software I have missed.
AmaSeis
Alan Jones' data logging software for Windows (free).
SEISAN, SEISLOG, SEISNET Institute for Solid Earth Physics software for Windows.
Article
describing Seislog.
WinQuake
Larry Cochrane's event viewing software for Windows ($35).
SDR
Larry Cochrane's data logging viewing software for Windows (free).
EMON
Ted Blank's data logging software for DOS (free).
6SMOWIN
Mauro Mariotti's data logging software for Windows (free).
Please
if you know some other software that I should list here.
I started on some Visual Basic software for data logging, but I have not had
much time to work on it. Perhaps we need an open software project to develop
seismic software. Please
if you have some interest in this type of project.
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Introduction
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FAQ
What kind of computer do I need for seismic data logging?
Almost any PC with Win3.1-95-98 will run Amaseis, Winquake, RighTime and AboutTime.
I use an old 90MHz Pentium with Win98 and 100Mb of free disk space.
This computer can run Amaseis at 20 samples per second input in the background,
plus Seti@home, and I can still use Winquake or other Windows programs while
the data logging continues. You need to have a connection to the Internet
to run the time correction program AboutTime. Note that Win2000 will NOT run the time
correction program Rightime since it
requires a modification of the (nonexistent) autoexec.bat file. Some new computers may
have USB ports instead of the older serial ports that the DataQ and microprocessor
serial input devices require, but you can generally
add a card that has these older COM type serial ports.
How do I tell if my system is working if I do not see quakes?
Quakes that are strong enough for you to detect may only occur once a
week or so, but the ocean waves generate a noise with a period of about
6 seconds that is detectable even in the center of the US. If you examine
a minute of so of your noise data you should see an oscillation that goes
through about 10 to 12 cycles every minute. These are called "microseisms".
If you do not see them, then your system may not be working correctly.
For answers to almost any amateur seismology question, search the
Public Seismic Network Mailing List Archives.
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Introduction
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SOME LINKS I HAVE FOUND USEFUL
ACCELEROMETERS
Mesmsic thermal based accelerometer chip (comparable to Analog Devices)
Parallax accelerometer sensor uses Memsic digital output chip.
Analog Devices iMEMS®: Integrated Micro-Electromechanical Systems (ADXL105 & ADXL202).
ADXL202 Technologies and Applications.
ADXL202EB evaluation board (pdf) this packages the surface mount ADXL202 into a DIP package.
ADXL105 Technologies and Applications (improved version of ADXL05).
Crossbow packaged Analog Devices accelerometers.
PSN-L Email list comment of Scientific American article on using ADXL05 sensors for seismic measurements.
(pdf)
Using the ADXL202/201 with the Parallax Basic Stamp Module to Speed
Algorithm Development Analog Devices application note.
(pdf)
Using the ADXL202 in Pedometer and Personal Navigation Applications
Analog Devices application note.
Using the ADXL202 with a microcontroller.
Strong Motion Data on a ADXL05 Sensor quake data recorded from accelerometer.
ShakeMaps: Southern CA and
Northern CA
maps of acceleration magnitudes during recent quakes.
How to solder surface mount parts (like ADXL chips) using a toaster oven.
Brown Dog Component Adaptors DIP adaptors for surface mount chips.
Digikey: Surfboard
adaptors to go from surface mount to through-hole (pdf file of
catalog page).
ADXL 14 pin carrier board use my HP laser printer file to print circuit traces for a home brew board.
BasicStamp List messages about using the ADXL and surface mount chips.
DIY Air-pencil soldering iron how to make one for under $20.
Surface Mount Secrets
ELECTRONICS RESOURCES
BOOKS
Search enginz all about second hand book search, including
book coupons.
Bookfinder compare used book prices.
BestBookBuys compare new book prices.
Amazon
Art of Electronics by Horowitz and Hill (THE BIBLE!).
Amazon
Active Filter Cookbook by Don Lancaster.
Amazon
Troubleshooting Analog Circuits by Bob Pease (THE GURU!).
Amazon
The Art and Science of Analog Circuit Design by Jim Williams.
Amazon
Analog Circuit Design : Art, Science and Personalities edited by Jim Williams.
Amazon
USB Complete: Everything You Need to Develop Custom USB Peripherals by Jan Alexson.
Amazon
Serial Port Complete by Jan Axelson.
CHIP SEARCH
FindChips
StockNet
QuestLink
ChipCenter
Need2Buy
USBid
CMB Components
Part Miner
CATALOG/ONLINE SALES
DigiKey
Mouser
Hosfelt
Allied
Newark
Jameco
SimCo,
OKW,
SerPac,
PacTec,
Fibox
inexpensive plastic enclosures.
MANUFACTURERS/DATA SHEETS
Burr-Brown
Dallas Semiconductor
Linear Technology
Maxim
Microchip
National
Texas Instruments
Analog Devices
MISC
Electronic Schematics on the Web
The Guru's Lair Don Lancaster's extensive links
GPS boards OEM board GPS for $79.
Newsgroups:
sci.electronics.basics,
sci.electronics.components and
sci.electronics.design.
MICROPROCESSOR RESOURCES
Circuit Cellar magazine for embedded control applications.
Microchip PIC 8-bit microprocessors
PicBasicPro for programming PIC microprocessors, and
email list with
searchable archives.
microCode Studio PICBasicPro Edition.
CCS PIC C for programming PIC microprocessors
(user exchange).
Peter H. Anderson resources on PIC embedded processor control
Parallax Basic Stamp processors - I got introduced to microprocessors here
DataQ DI-151RS Low Cost, 12 Bit A/D Serial Port Starter Kit As Sold By Radio Shack.
Newsgroups:
comp.dsp,
alt.microcontrollers.8bit and
comp.arch.embedded.
PIC Tutorial:
Understanding & Programming the PIC16C84 A beginners' tutorial.
PICLIST email list for people interested in the Microchip PIC.
MECHANICAL PARTS AND LAB EQUIPMENT SOURCES
ScienceLab lab equipment and chemical supply.
Rare-Earth Magnets
sells new magnets.
ForceField sells recycled magnets
Hamilton Core Drill Bits neodymium magnets.
Grainger hardware distributor (magnets, etc.)
McMaster Carr hardware distributor (magnets, nuts, bolts, metals, etc.)
SOFTWARE
AktivFilter software for designing perfect active filters with real components.
AmaSeis freeware seismic data acquisition program.
Instructions for using Amaseis to analyze seismic data.
WinQuake seismic event viewing software.
Instructions for using WinQuake to analyze seismic data.
Spectrogram 5.1 freeware audio spectrum analysis software.
FilterLab freeware tool that simplifies active filter design.
RighTime corrects the drift in your inaccurate PC clock.
AboutTime freeware uses the internet to precisely reset your PC clock.
TaskInfo shareware that monitors the resources used by PC programs.
SEISMIC
BOOKS
Seismology Bibliography and Book Reviews.
Bookfinder search for used books on reading seismograms etc.
BestBookBuys compare new book prices.
Amazon
Earthquakes Bruce Bolt, 1999 4th Edition - great introduction.
Amazon
Earthquakes and Geological Discovery by Bruce Bolt, Sci. Am. Library, 1993.
Amazon
Modern Global Seismology Lay and Wallace, 1995.
Amazon
Quantitative Seismology: Theory and Methods Aki, 2001.
OTHER
SemismicNet Redwood City Public Seismic Network (extensive information!)
Lehman the man who built the first
Lehman Seismometer described in the July, 1979 Scientific American Magazine.
Lehman Manual (PDF format) "Instructions for Construction of Lehman Seismometer
by Kelly Knight - May 2000.
Newsgroups:
sci.geo.earthquakes and
seismic.general.
AZPEPP Arizona - Princeton Earth Physics Project
GEOPHONES
Introduction to Geophones.
Infiltec QM-4.5 short period geophone seismometer.
Geophone FAQ lists several manufacturers.
Geophone Model L-28 spec sheet (224k pdf).
Geophone Model L-15 spec sheet (205k pdf).
Walt's Geophone FAQs Selected PSN Geophone Postings.
Vault construction for your seismometer by the
Indiana University PEPP Program.
Vault construction for your seismometer by the
IRIS PASSCAL Program.
Improving a Geophone to produce a broadband seismometer.
RT Clark sells used geophones.
Sercel parent company of Mark Products geophones.
eBay sometimes lists geophones.
NZ Geophone System Design shows circuit diagram and geophone mounting.
PSN equipment for sale may include geophones.
Simple procedure tests transducer EDN Magazine Design Ideas: March 1, 1996.
Remote 2-Wire Geophone Preamp Linear Technology design idea.
CablesToGo source for 25',50',100' extension serial cables for Infiltec geophone system
(DB9, M/F).
PRINTED CIRCUIT BOARDS
BPECS: PCB Circuit Design Package (very inexpensive.)
CADSOFT: Eagle PCB Circuit Design Package.
Electronic Assembly News list of pcb sources.
AP Circuits quickturn prototype pcb's for under $100.
EP Circuits quickturn prototype pcb's can include solder mask.
Olimex Ltd. in Bulgaria lowest proto prices, 2 week delivery to US via air mail.
(4"x6" PCB, double-side, WITH silkscreen + solder mask, for $26 plus $8 Airmail)
Advanced Circuits good prices on production runs of pcb's.
Pulsar great prices on production runs of pcb's.
NeatSite links related to PCBs.
Making Printed Circuit Boards book by Jan Alexson.
How to Make PCBs This is how I make them.
OTHER INTERESTING BUT LESS RELEVANT PAGES
SoPrePlaTec (pronounced "soapy platex")
The Society for the Prevention of Plate Tectonics.
Sensors an awesome link page!
Vernier Science Hardware and Software for the Classroom.
Tinkers Guild Resources for Hands-on Science - sells CD of
projects from the Scientifc American Amateur Scientist
column.
Society for Amateur Scientists online projects and supplies.
Detecting Extraterrestrial Gravity by Shawn Carlson,
from the January 2000 Scientific American Amateur Scientist Column.
Detecting Micron-Size Movements by Shawn Carlson,
from the August 1996 Scientific American Amateur Scientist Column.
Earth Songs If humans had radio antennas instead of ears, we would hear a remarkable symphony of strange noises coming from our own planet.
Infrasound Monitoring with a Microbarograph
How to detect low frequency acoustic waves in the atmosphere.
Crackpot Inventor original electronic devices, tools for clockmaking and repair, and a variety of other unusual handmade products.
Mad Scientist Network the laboratory that never sleeps.
SOME OF MY OTHER INTERESTS
Join the SETI@Home search for extraterrestrial intelligence.
Here are my statistics.
Please join my team Dickster.
Join the Einstein@Home search for gravitational waves.
Here are my statistics.
Please join my team Dickster.
Join the Predictor@Home predict protein structure.
Here are my statistics.
Please join my team Dickster.
Join the SIMAP@Home compute Similarity Matrix of Proteins.
Here are my statistics.
Please join my team Dickster.
Join the Rosetta@Home determine the 3-dimensional shapes of proteins.
Here are my statistics.
Please join my team Dickster.
My Business Page Infiltec Air Leakage Control.
My Other Link Page building science, books, travel, etc...
My fun page jokes and travel photos.
My
Gold Prospecting Near Washington, DC Page.
My
SID-GRB@home how to build a simple VLF radio receiver that can detect
Gamma-Ray Bursts (GRB) from the edge of the universe.
My
Infrasound@home how to build an inexpensive microbarograph for detecting infrasound(sounds below 20 Hz).
Please
any suggestions or corrections to my seismometer
related links.
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all rights reserved.
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and last updated on April 27, 2006.
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