A digital recorder for lightning current waveforms

摘要

This paper describes an improved lightning current recorder having an efficient analog to digital conversion method. To distinguish between multiple lightning strokes which typically follow each other in about 30 ms, the dead-time (the time required to down-load samples) has been reduced by discarding redundant information. With a maximum sampling rate of 5 MSPS and 6-bit linear quantization, the dead-time for a severe 200-kA stroke is 12.43 ms. Logarithmic quantization combined with a faster microprocessor (an 8085 AH-2 running at 10 MHz) and more efficient software would reduce this to 2.6 ms.