Please note, we've upgraded our 1-Wire detector with a Boltek Stormtracker. This page is here for historical and informational purposes. We still feel the 1-Wire detector is a great sensor for the price.
LD3-R2 Lightning Detector - How it works
This lightning detector is a 1-Wire hobbyist device from Hobby Boards. It detects the electromagnetic pulse from lightning discharge. This is the same effect that causes interference in television and radio reception during a thunderstorm.
As far as I know, CarterLake.org has the only lightning detector in the Omaha/Council Bluffs area providing warning and information on the Internet. It certainly is the only detector in Carter Lake.
Actual size of the board is approx. 3.5" x 1"
Also see: Lightning Safety
Grounding
The most important factor in the operation of the LD3-R2 1-Wire Lightning Detector is a good ground. If you mount it outdoors, you will want to install a grounding rod into the earth at a depth of at least 6 feet and connect the detector to this grounding rod. Since mine is located indoors, I have it connected to my house electrical ground.
Reception
Mounting the antenna 10 or more feet into the air allows the device to sense lightning strikes 30 to 50 miles away. Originally, I had the detector at ground level in a window, but it's range was virtually zero. So, I moved the detector and mounted it on an exterior wall approximately 11 feet in the air.
Currently, I am experimenting with antenna designs to optimize reception. I started with a monopole extendable radio antenna (pictured at the bottom of the page) but was unhappy with both detection and range.
I went and bought a cheap $10 16" kettle-style grill (with a smaller grate for the charcoal). I used my Dremel on the grates to cut off the outer ring so I was left essentially with two variable-wavelength Log Periodic Dipole Array antennae - one from each grate. I then mounted them horizontally one on top of the other at 90 degrees. The larger one is oriented East/West (the direction of most storms); the smaller is North/South. I joined them only in the middle with a bit of wire and then connected this to the detector.
By doing this, I increase the number of elements which will be hit by the pulse. This increases the strength of reception, making for a more sensitive antenna. Increased sensitivity allows for greater range and greater sensitivity to inner-cloud lightning.
I believe the detector has sensed lightning strikes up to 100 miles away with this setup.
Lightning detected from April 20, 2005 thunderstorm.
Storm hit around 6 am, so the detector provided warning of it's strength.
Lightning detected from May 31, 2005 thunderstorm.
This intense thunderstorm produced at times over 300 area strokes per hour.
Why just a counter?
Cost mainly. This 1-Wire detector was put together for around $90 total (much less if you order electronics individually and solder yourself). A Boltek StormTracker sensor costs substantially more ($399 + $170 for software) for only a moderate increase in features - mapping with approximate direction and distance. A map is pretty, but more important is the knowledge that strikes are occurring in our area and therefore a danger.
To interface with our computer, the lightning detector uses AAG Electronica's USB 1-Wire Adapter. An added benefit of this tiny piece of equipment is that it allows the addition of more 1-Wire devices, something I plan to pursue as our current weather station wears out. The advantage of 1-Wire, besides having a large variety of highly accurate weather devices, is that each piece can be purchased individually as afforded.
Update 09/05/05 - Hobby Boards has really responded to it's customers. You can now buy the 1-Wire USB adapter or a serial port adapter direct from them. Also, the detector board is up to v3.6, which includes plug-n-play RJ45 ports for easy hookup and screw terminals for antenna connection. Hobby Boards has a great list of products and comes highly recommended. You can build an entire 1-Wire weather station through them for less than $250.
Software
The software used to present the information on the Internet is Weather Display. Software creator Brian Hamilton has done a wonderful job incorporating lightning data in the software. No other weather software has so many built-in features and comes highly recommended.
Special thanks to Bob in Jacksonville, Fl and Chaz in Dayton, Md for their assistance and inspiration.
Equipment list:
• LD3-R2 Lightning Detector
• RJ11 Phone cord
• 9V Battery
• 40" Replacement rod antenna (Radio Shack)
• PVC Electrical box (Home Depot)
• Misc. bolts, nuts, extra wire (for ground and connections)
Fast Facts:
• If you can see it or hear it, lightning can hit you. Find shelter now.
• Lightning is the No. 2 weather killer in the US (behind floods).
• Every 5 seconds between flash and boom is a mile's distance from you.
• Under ideal conditions, lightning's thunder can be heard 12 miles away.
• Lightning is really no wider than a few inches.
• All thunderstorms produce lightning.
Additional links:
Hobby Boards
Testing your house ground
Weather Display detector setup FAQ and further reading
Lightning Detector WD installation instructs
Build a lightning detector
1-wire Lightning Detector - Open Discussion
