switches jack in Software

Encoder EAN-13 in Software switches jack

RCA jack - signal output jack for data collection SO-239 - Antenna-2 input jack Antenna-1 - RCA jack for whip or outdoor Ant Capacitive Hat (see text)

Misc IC and transistor sockets, wire, PC board Multi-voltage Power Supply R1 R2 5 k potentiometer (trimmer) 240 ohm, 14watt, / 5% resistor

C1,C4,C7 4700 F, 50 volt electrolytic capacitor C2,C5,C8 1 F, 50 volt ceramic disk capacitor C6,C6,C9 10 F, 50 volt electrolytic capacitor BR1 4-diode bridge rectifier 3 amp, 100 volt U1 LM317 - (+) voltage adjustable regulator

A point is reached (usually when the gradient exceeds tens of thousands of volts per inch) where the ionized air begins to act like a conductor At this point, the ground sends out feelers to the cloud, searching for a path of least resistance Once that path is established, the cloud-to-earth capacitor discharges in a bright flash of lightning Because there is an enormous amount of current in a lightning strike, there s also an enormous amount of heat (in fact, a bolt of lightning is hotter than the surface of the sun) The air around the strike becomes super heated, hot enough in fact that the air immediately close to the strike actually explodes The explosion creates a sound wave that we call thunder A typical high energy lightning strike is shown in Figure 16-1 Cloud-to-ground strikes are not the only form of lightning though There are also ground-to-cloud (usually originating from a tail structure) and cloudto-cloud strikes These strikes are further defined into normal lightning, sheet lightning, heat lightning, ball lightning, red sprite, blue jet, and others that are lesser defined For more information on lightning, see: http://sciencehowstuffworkscom/lightninghtm Satellites are more often used to follow lightning strikes around the world but haven t advanced to the point where they can accurately map local areas There are two major types of sensors commonly used magnetic direction finders and VHF Interferometery The National Lightning Detection (NLDN), which is operated by Global Atmospherics, Inc, (GAI) in

Tucson, AZ, is a network of more than 130 magnetic direction finders that covers the entire USA more than twice the coverage of existing weather radar networks Each direction finder determines the location of a lightning discharge using triangulation and is capable of detecting cloud-to-ground lightning flashes at distances of up to 250 miles and more Processed information is transmitted to the Network Control Center where it s displayed in the form of a grid map showing lightning across the USA: (wwwlightningstormcom/tux/jsp/gpg/ lex1/mapdisplay_freejsp) Recently, NASA has improved the resolution of the system by adding acoustical measurements to the mix Although the flash and resulting thunder occur at essentially the same time, light travels at 186,000 miles per second, whereas sound travels at the relative snail pace of one-fifth of a mile in the same time Thus, the flash if not obscured by clouds is seen before the thunder is heard By counting the seconds between the flash and the thunder and dividing by 5, an estimate of the distance to the strike (in miles) can be made In the NASA lightning sensor, a low frequency receiver detects the lightning strike The leading edge of the electric-field pulse is used to start a timer and the leading edge of the thunder pulse is used to stop the timer A microcontroller in each receiver transmits the time measured to a processing station, where the times are converted to distances that are used to compute the location of the lightning strike to within l2 inches However, the NASA sensors have to be located within a 30 mile radius of the strike to be accurate If you are interested in monitoring static levels around you in stormy weather, and the ability to have some advance warning of an impending storm, then this circuit will be of great interest to you especially if you are involved in the radio hobby and have antennas high in the air The Lightning Storm Monitor has proven to be very reliable and useful for advanced storm warning activities The Lightning Monitor circuit is shown in the schematic in Figure 16-2 The Lightning Monitor is actually two receivers in one, a spheric monitor and a static electricity monitor The static monitor portion of the circuit begins at the outdoor Antenna-2, a capacitive hat type antenna which is fed with coax from the antenna to the receiver The gate of the P JFET is tied