公开(公告)号：US5671147A

公开(公告)日：1997-09-23

申请号：US514197

申请日：1995-08-11

申请人： James B. McKim, Jr. ,  John F. Kenny, Jr.

发明人： James B. McKim, Jr. ,  John F. Kenny, Jr.

IPC分类号： G01R19/25 ,  G01R23/20 ,  G06F17/40

CPC分类号： G01R19/25 ,  G01R23/20

摘要： A digital system measures cyclic disturbance signals on an electrical line that are induced by a connected unit under test (UUT). The system includes a digital to analog (D/A) converter which receives and converts a first train of digital signals to a cyclic analog test signal and applies that signal to the electrical line. An analog to digital (A/D) converter receives and converts analog cyclic disturbance signals from the electrical line to a second train of digital signals. A synch generator applies a train of synch pulses, concurrently, to synchronizing inputs of the D/A converter and the A/D converter so that their respective conversion operations are based upon a common time-base signal. A processor is coupled to the D/A converter and A/D converter and outputs the first train of digital signals to the D/A converter and receives the second train of digital signals from the A/D converter. The processor subjects a portion of the second train of digital signals to signal analysis, with the portion of the second train being representative of an integer number of cycles of the cyclic disturbance signal sensed from the electrical line. The clock frequency which causes generation of the synch pulses is selected so that the synch pulses have a precise, predetermined relationship to a predetermined number of cycles of the cyclic signal (in the case of a power spectrum analysis) or a predetermined number of half cycles (in the case of an amplitude analysis).

摘要翻译： 数字系统测量由被测单元（UUT）引起的电线上的循环干扰信号。 该系统包括数模（D / A）转换器，其将第一列数字信号接收并转换为循环模拟测试信号，并将该信号施加到电线。 模数（A / D）转换器接收并将模拟循环干扰信号从电线转换成第二列数字信号。 同步发生器同时施加一串同步脉冲，以同步D / A转换器和A / D转换器的输入，使得它们各自的转换操作基于公共时基信号。 处理器耦合到D / A转换器和A / D转换器，并将第一串数字信号输出到D / A转换器，并从A / D转换器接收第二列数字信号。 处理器对第二列数字信号的一部分进行信号分析，其中第二列的部分表示从电线感测的循环干扰信号的整数个周期。 选择产生同步脉冲的时钟频率，使得同步脉冲与循环信号（在功率谱分析的情况下）或预定数量的半周期的预定数量的周期具有精确的预定关系 （在振幅分析的情况下）。