公开(公告)号：US5576628A

公开(公告)日：1996-11-19

申请号：US316598

申请日：1994-09-30

申请人： Amado A. Caliboso ,  S. Fred Dabney, Jr.

发明人： Amado A. Caliboso ,  S. Fred Dabney, Jr.

IPC分类号： G01R27/26

CPC分类号： G01R27/2605

摘要： A capacitance measuring device incorporates the integrating analog-digital converter circuit of a handheld meter. The capacitance measuring device charges an unknown capacitance with a constant current until the voltage across the unknown capacitor reaches a predetermined voltage. At the same time, a reference voltage is applied to the input lead of an integrating circuit of the integrating analog-digital converter such that a corresponding proportional charge is stored in the feedback capacitor of the integrating circuit. The negative of the reference voltage is then applied to the integrating circuit so that charge is removed from the feedback capacitor at the same rate as the feedback capacitor was charged. A counter is used to determine the number of clock pulses it took to completely discharge the feedback capacitor and hence a reading of the unknown capacitance can be determined from the equation C.sub.X =I.sub.CHARGE *T.sub.2 /V.sub.TRIP.

摘要翻译： 电容测量装置包括手持式电表的集成模数转换电路。 电容测量装置以恒定电流对未知电容充电，直到未知电容器两端的电压达到预定电压。 同时，对积分模数转换器的积分电路的输入引线施加参考电压，使得对应的比例电荷存储在积分电路的反馈电容器中。 然后将参考电压的负值施加到积分电路，使得以与反馈电容器充电相同的速率从反馈电容器去除电荷。 计数器用于确定完全放电反馈电容器所需的时钟脉冲数，因此可以从等式CX = ICHARGE * T2 / VTRIP确定未知电容的读数。