Multiple channel power line monitor

Claim 1

Apparatus for monitoring a plurality of electrical power carrying lines comprising: a plurality of channel circuits, each channel circuit including: (a) an input adapted to be coupled to one of said power carrying lines for sensing the signal thereon, (b) trigger detector means for producing a trigger detect signal in response to said sensed signal at said input exceeding a predetermined reference level, (c) analog-to-digital converter means for controllably converting said sensed signal at said input to corresponding digital signals, (d) memory means for controllably storing said analog-to-digital converter means produced digital signals, and (e) timing and control circuit means responsive to control signals for controlling said analog-to-digital converter means and said memory means; a common logic circuit comprising: (a) a sampling clock generator means for producing a sampling clock signal, said sampling clock signal being coupled to each channel circuit timing and control circuit means for controlling the sampling rate of the corresponding analog-to-digital converter, (b) channel select logic means responsive to control signals for selecting a predetermined one of the plurality of channel circuits, and (c) digital-to-analog converter means for converting the stored digital signals in a selected channel circuit memory means to a corresponding analog signal; and control logic means for controlling the operation of the channel circuits and the common logic circuit in either a selected manual or an automatic mode, said control logic means including storage means for controllably storing digital signals, the control logic means being operable in the manual mode for: (a) responding to a trigger detect signal produced by the trigger detector means of a channel circuit to cause the channel select logic means to select said channel circuit such that an analog signal out of said digital-to-analog converter means is provided for review by an operator, and (b) providing an operator with a means for loading the digital signals stored in the memory means of said selected channel circuit into said storage means, the control logic means being operable in the automatic mode for: responding to a trigger detect signal produced by the trigger detector means of a channel circuit to cause the memory means of said channel circuit to load the digital signals stored therein into said storage means; said control logic means including means operable in the manual mode and the automatic mode for assigning a predetermined priority to each of the channel circuits such that in the even at least two trigger detector means produce trigger signals simultaneously, each circuit channel is processed in the order of its assigned priority.