Time interval measurement method and apparatus
AssigneeTektronix, Inc.
InventorsPedro Max Janowitz, James William Godwin
Life of this patent
Estimating the term…
Abstract
A method and apparatus is disclosed for providing accurate time interval measurements in an oscilloscope. A first voltage which is proportional to the time position of a first selected point along a linear time-base sweep is stored and applied to a subtractor circuit. A second voltage proportional to the time position of a second selected point along the sweep is applied to the subtractor, and the difference between the first and second voltages is obtained. This difference, which is proportional to the time interval between the first and second selected points, is applied to a digital voltmeter calibrated to provide a display in time units.
Claims11
A method for measuring selectable time intervals along a linear ramp time-base waveform, comprising the steps of:
- selecting a first voltage which is proportional to the time position of a first selected point along said time-base waveform;
- storing said first voltage in a memory device;
- selecting a second voltage which is proportional to the time position of a second selected point along said time-base waveform;
- subtracting said first voltage from said second voltage in an arithmetic device to produce a difference voltage proportional to the time difference between said selected points;
- and
- applying said difference voltage to a digital voltmeter adapted to provide a numerical readout in time units.
An apparatus for measuring selectable time intervals along a linear ramp time-base waveform, comprising:
- means for selecting first and second voltages which are proportional to first and second selected points along the time axis of said time-base waveform;
- memory means for storing said first voltage;
- means for subtracting said first voltage from said second voltage so that a difference voltage proportional to said time interval is produced;
- and
- digital voltmeter means for receiving said difference voltage and providing a readout thereof.
An apparatus for measuring selectable time intervals along a linear ramp time-base waveform, comprising:
- selection means for selecting points along the time axis of said time-base waveform and generating voltage values proportional thereto;
- memory means for selectively storing said generated voltage values;
- subtraction means for receiving said stored voltage values and said generated voltage values and producing a difference voltage value therefrom, whereby said voltage value difference is proportional to the time interval between selected points;
- and
- digital voltmeter means for receiving said difference voltage value and providing a readout thereof in time units.
A time interval measurement system in an oscilloscope, comprising:
- at least one sweep generator for generating time-base sweep waveforms;
- time position selection means for selecting points along the time axis of said time-base waveforms and generating voltages proportional thereto;
- memory means for selectively storing values of said generated voltages;
- subtraction means for receiving voltage values from said time position selection means and said memory means and producing the arithmetic difference between said values;
- and
- voltmeter means for receiving said difference and providing an indication thereof in time units, said difference being proportional to the time interval between said selected points.
Dependencies are inferred from the claim text.