Overview: Lightning strikes are a powerful natural phenomenon. Around the world there are 40 to 50 lightning strikes per second. Lightning is a very high energy phenomenon that if not protected against can cause catastrophic damage to electrical, electronic, and electromechanical devices in the vicinity of the strike, as well as causing thermal meltdowns, fires, and deaths to animals and humans. An average lightning strike has a total duration of from 60 to 200 microseconds carrying an average current of 30 kA, and travels at a speed of approximately 1 x 108 m/sec. A typical strike transfers 15 Coulomb of charge and 500 megajoules of energy. Super bolts can be as large as 120 kA and transfer 350 Coulombs of charge. (ref.: Wikopedia)
Most structures in the developed world are protected, to a degree, from lightning strikes by utilizing specially designed grounding systems. The grounding systems are designed to form a controlled pathway for very large electrical currents from the structure (eg. A cell tower) into the Earth ground. Such grounding systems typically utilize one or more very heavy cable conductors attached at strategic points on the structure, and then connected to an array of conductive grounding rods(ranging from ten to 100 feet long) which are driven into the earth ground. The idea is to enable a safe pathway for the transfer of charge during the lightning strike from the structure to earth ground, bypassing parts of the structure that could be highly succeptible to damage from high currents, voltages, magnetic fields, and heat generated by the lightning, if left undirected in finding earth ground.
For such structures that utilize grounding system(ranging from water towers to RF towers, to refineries, large buildings, and various manufacturing plants, to mention a few), there is a desire to be able to know, and actually keep count of, lightning strikes at a particular facility. Not nearby(miles from) the facility, but at the facility. The use of this knowledge is primarily for maintenance of the grounding system components as well as for inspection of parts of the structure itself(eg. Automated control systems, computers, etc., that still might have suffered damage despite the grounding system).
So this project involves designing and building a device to detect and count lightning strikes, nearby the strike point, or nearby the earth grounding rods of the grounding system. In this context “nearby” is on the order of a few feet (eg., not km or miles).
Desired Operational specifications for the Lightning Detector device are as follows:
The device will be relatively small in size and weight(eg. Handheld) and able of surviving the elements- weather
The device will have an LCD display that will display a lightning strike count as well as a date/time of each detected lightning strike.
The device will have two flashing LEDs. One indicates the device is operational. The second indicates that at least one lightning strike was detected, if flashing. Note- use short duty cycle flashing to minimize power consumption.
The clock in the device must be user settable using one or two pushbuttons and a simple procedure.
The device must be re-settable using some simple procedure. Obviously the device is re-usable to the extent it does not get destroyed by a direct lightning hit, itself.
The device must be battery powered and operational for at least 6 months in the field
The device (production) parts cost must be under $25. Assume a production quantity of 5,000 for parts pricing.
The device would ideally be Faraday cage shielded as much as possible for lightning protection itself, however keep in mind the sensors being used will likely need to be outside of the device.
Operating temperature range of 32 to 130 deg F.
Most structures in the developed world are protected, to a degree, from lightning strikes by utilizing specially designed grounding systems. The grounding systems are designed to form a controlled pathway for very large electrical currents from the structure (eg. A cell tower) into the Earth ground. Such grounding systems typically utilize one or more very heavy cable conductors attached at strategic points on the structure, and then connected to an array of conductive grounding rods(ranging from ten to 100 feet long) which are driven into the earth ground. The idea is to enable a safe pathway for the transfer of charge during the lightning strike from the structure to earth ground, bypassing parts of the structure that could be highly succeptible to damage from high currents, voltages, magnetic fields, and heat generated by the lightning, if left undirected in finding earth ground.
For such structures that utilize grounding system(ranging from water towers to RF towers, to refineries, large buildings, and various manufacturing plants, to mention a few), there is a desire to be able to know, and actually keep count of, lightning strikes at a particular facility. Not nearby(miles from) the facility, but at the facility. The use of this knowledge is primarily for maintenance of the grounding system components as well as for inspection of parts of the structure itself(eg. Automated control systems, computers, etc., that still might have suffered damage despite the grounding system).
So this project involves designing and building a device to detect and count lightning strikes, nearby the strike point, or nearby the earth grounding rods of the grounding system. In this context “nearby” is on the order of a few feet (eg., not km or miles).
Desired Operational specifications for the Lightning Detector device are as follows:
The device will be relatively small in size and weight(eg. Handheld) and able of surviving the elements- weather
The device will have an LCD display that will display a lightning strike count as well as a date/time of each detected lightning strike.
The device will have two flashing LEDs. One indicates the device is operational. The second indicates that at least one lightning strike was detected, if flashing. Note- use short duty cycle flashing to minimize power consumption.
The clock in the device must be user settable using one or two pushbuttons and a simple procedure.
The device must be re-settable using some simple procedure. Obviously the device is re-usable to the extent it does not get destroyed by a direct lightning hit, itself.
The device must be battery powered and operational for at least 6 months in the field
The device (production) parts cost must be under $25. Assume a production quantity of 5,000 for parts pricing.
The device would ideally be Faraday cage shielded as much as possible for lightning protection itself, however keep in mind the sensors being used will likely need to be outside of the device.
Operating temperature range of 32 to 130 deg F.