Counter Patents

Brooke Clarke 2006 - 2023

In order to determine the frequency of an oscillator it's necessary to make either a frequency measurement, or maybe better a Time Interval measurement.  It turns out that the one shot precision of the counter is very important.  The precision can be improved by averaging but the stability of the oscillator being measured may not allow it's frequency to remain stable during the averaging process and so the answer is not as good as it might be if a better counter was used.

This all related to the Allan plot for the counter superimposed on the plot for the oscillator.  Averaging causes the counter line to have a slope of -1.  This topic is covered in an HP Journal paper "Time Interval Averaging: Theory, Problems, and Solutions" by David Chu, 1974 pp12-15.

"Universal Counter Resolves Picoseconds in Time Interval Measurements", by David C. Chu, Mark S. Allen, and Allen S. Foster, HP Journal Aug 1978 - HP 5370

4150432 Frequency counter and method, James L. Sorden, HP, 1979-04-17, - 702/78
3304504 Gate generator synchronizer,    Feb., 1967    Horlander    364/484.
3555256 Automatic electronic counter apparatus, GR,    Jan., 1971    Westlake    364/701.
3609326 Counting apparatus and method using separate counters for reference and unknown signal, HP   Sep., 1971    Bagley et al.    364/551.
3631343 Time interval averaging circuit, HP   Dec., 1971    Schmidhauser    324/186.
4073432  Circuit arrangement for determining the average value of a frequency  Feb., 1978    Schroder    324/78.

4164648 Double vernier time interval measurement using triggered phase-locked oscillators, David C. Chu, HP, 1979-08-14, -
"The Triggered Phase-Locked Oscillator", David C. Chu, HP Journal Aug 1978 -

5912728 Device for precisely measuring the duration of a time interval
5717659 Device for measuring the duration of a time slot,
5570326 Device for measuring the duration of a time interval,

7085668  Time measurement method using quadrature sine waves Aug 1, 2006, 702/117 ; 702/176; 702/72; 702/78; 714/700

3320546 Variable frequency controlled frequency divider, Robert L Allen, Alan S Bagley, HP, 1967-05-16, - Model 5260A 12.4 GHz Frequency Divider, HP Journal April 1967, used with the HP 5245L counter.

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page created 21 Dec 2006.