MEASURING APPARATUS FOR LIGHTING SURGE WAVE TAIL LENGTH

• Main Authors: ADACHI KEIJI, UEDA YOSHINOBU
• Format: Patent
• Language: English
• Published: 06.07.1982
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; METEOROLOGY; PHYSICS; TESTING

PURPOSE:To enable direct indication of a measured value of a wave tail length of a lightening surge by detecting the first transition of the surge and falling by 1/2 in the instantaneous value thereof to count the time between the two detections. CONSTITUTION:An input circuit 2 outputs a voltage to be measured proportional to the instantaneous value of a lightning surge. A high speed comparator circuit A1 inverts the output level the moment the instantaneous value of the voltage to be measured, which permits a level conversion circuit 5 to output a signal of a high level to open an AND gate and a reference time signal 11 is input into a counter 12. On the other hand, a high speed peak hold circuit 3 whose output is arranged to follow the voltage to be measured retains the maximum value (e) when the voltage reaches it. A high speed comparator circuit A2 inverts the output from a negative potential to a positive potential the moment the voltage to be measured falls by 1/2 (e). This enables a level conversion circuit 7 to output a signal of a high level to reset R-SFF thereby halting the counting of the counter 12. Thus, the counter 12 counts the length of the wave tail which will be displayed.