US 4,541,105 A · Counting apparatus and method for frequency sampling

Abstract

An apparatus and method for counting the number of cycles of a sensor signal and of a reference signal that occur during respective time intervals associated with a sampling interval defined by a sample signal. Sensor and reference gate signals are produced and respectively define sensor and reference intervals. The sensor interval begins and ends synchronously with respect to the sensor signal, and the reference interval begins and ends synchronously with respect to the reference signal. The sensor, reference and sampling intervals are approximately coextensive with one another. Cycles of the sensor and reference signals are counted during the sensor and reference intervals, respectively. The process may be repeated for a plurality of successive sampling intervals.

Claims16

Dependent claims

An apparatus for counting the number of cycles of a sensor signal and of a reference signal that occur during respective time intervals associated with a sampling interval defined by a sample signal, whereby the relationship of the frequency of the sensor signal to the frequency of the reference signal may be determined, the apparatus comprising:

gating means responsive to the sample signal and to the sensor and reference signals for producing a sensor gate signal and a reference gate signal, the sensor gate signal having a characteristic thereof that is operative to define a sensor interval that begins and ends synchronously with respect to the sensor signal, the reference gate signal having a characteristic thereof that is operative to define a reference interval that begins and ends synchronously with respect to the reference signal, the sensor, reference and sampling intervals being approximately coextensive with one another;
sensor count means for counting the number of cycles of the sensor signal that occur during the sensor interval;
and
reference count means for counting the number of cycles of the reference signal that occur during the reference interval.

1 more element

A method for counting the number of cycles of a sensor signal and a reference signal that occur during respective time intervals associated with a sampling interval defined by a sample signal, whereby the relationship of the frequency of the sensor signal to the frequency of the reference signal may be determined, the method comprising:

producing a sensor gate signal and a reference gate signal in response to the sample signal and to the sensor and reference signals, the sensor signal having a characteristic thereof that is operative to define a sensor interval that begins and ends synchronously with respect to the sensor signal, the reference gate signal having a characteristic thereof that is operative to define a reference interval that begins and ends synchronously with respect to the reference signal, the sensor, reference and sampling intervals being approximately coextensive with one another;
counting the number of cycles of the sensor signal that occur during the sensor interval;
and
counting the number of cycles of the reference signal that occur during the reference interval.

1 more element

An apparatus for measuring an input variable comprising:

(a) a sensor for producing a sensor signal, the frequency of the sensor signal corresponding to the value of the input variable;
(b) means for producing a periodic reference signal;
(C) means for producing a sample signal that is operative to define a sampling interval;
(d) counting means for counting the number of cycles of the sensor signal and of the reference signal that occur during respective time intervals associated with the sampling interval, the counting means further comprising:
(1) gating means responsive to the sample signal and to the sensor and reference signals for producing a sensor gate signal and a reference gate signal, the sensor gate signal having a characteristic thereof that is operative to define a sensor interval that begins and ends synchronously with respect to the sensor signal, the reference gate signal having a characteristic thereof that is operative to define a reference interval that begins and ends synchronously with respect to the reference signal, the sensor, reference and sampling intervals being approximately coextensive with one another;
(2) sensor count means for counting the number of cycles of the sensor signal that occur during the sensor time interval and for producing a corresponding digital sensor count signal;
(3) reference count means for counting the number of cycles of the reference signal that occur during the reference time interval and for producing a corresponding digital reference count signal;
and
(e) processor means for receiving the sensor and reference count signals and determining therefrom the value of the input variable.

6 more elements

Dependencies are inferred from the claim text.

Counting apparatus and method for frequency sampling

Life of this patent

Counting apparatus and method for frequency sampling

Life of this patent

Abstract

Claims16