David T Sommer

US Patent:

45890749, May 13, 1986

Filed:

Aug 31, 1983

Appl. No.:

6/527999

Inventors:

Teddy R. Thomas - Renton WA
David L. Sommer - Everett WA
Greg J. Von Bokern - Kent WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

G01R 1900

US Classification:

364483

Abstract:

A power line monitor capable of monitoring multiple power lines simultaneously includes a channel circuit for each monitored line, a common logic circuit and control logic. The signal on each power line is analog-to-digital converted and stored in channel circuit memory. A trigger detector produces a trigger detect signal in response to the monitored signal exceeding a preset limit. The trigger detect signal initiates a delay time during which the conversion and storing process in the triggered channel continues. The delay time is selected such that a desired amount of both pre- and post trigger data is retained in the associated channel memory. The control logic is operable in either a manual or an automatic mode. In the manual mode, memory stored data in a triggered channel is repetitively cycled to a digital-to-analog converter provided in the common logic, whereby an operator can monitor the stored waveform and, if desired, load the channel memory contents to magnetic tape. In the automatic mode, the control logic loads the associated channel memory directly to magnetic tape, then resets the channel in preparation for continued power line monitoring.