Coded data generation or conversion – Analog to or from digital conversion – Analog to digital conversion
Patent
1987-09-02
1989-03-14
Shoop, Jr., William M.
Coded data generation or conversion
Analog to or from digital conversion
Analog to digital conversion
341124, H03M 160
Patent
active
048128481
ABSTRACT:
A method and apparatus of converting analog voltage signals to digital frequency signals comprises a voltage to frequency converter having an output which produces pulse trains that are proportional to the voltage level of an analog voltage signal applied to the converter. A microprocessor is connected to the converter for sampling the pulse trains during a fixed sampling period. The microprocessor detects the leading edges of the first and last pulse in the pulse train, stores the occurrence time for the two leading edges and then subtracts the occurrence times to calculate the duration time for all the pulses in the sample period between the leading edges of the first and last pulses. A counter counts the number of pulses between the first and last pulse, and a calculation is made dividing the number of pulses by the time duration to yield an accurate measurement of the frequency for the pulse train. A precision reference voltage along with a plurality of analog voltage signals to be measured, is applied to the plural inputs of a multiplexer. The output of the multiplexer is then amplified and a level shifted before it is applied to the converter. The microprocessor drives the multiplexer to sequentially apply signals to the converter. During each complete cycle of the multiplexer the microprocessor receives a pulse train corresponding to the reference voltage signal. A stored frequency for that reference pulse train is then compared to the actual frequency which results from the reference voltage to determine whether any shifts in ambient conditions have caused shifts in the output of the converter. This shift is interpreted as being caused by changes in ambient condition and is applied equally to all other measured frequencies. In this way, inexpensive components can be used while still maintaining accuracy for a wide range of ambient conditions.
REFERENCES:
patent: 4521763 (1985-06-01), Murao et al.
patent: 4558301 (1985-12-01), Trofimenkoff et al.
Edwards Robert J.
Hoff Marc S.
Matas Vytas R.
Shoop Jr. William M.
The Babcock & Wilcox Company
LandOfFree
Analog to digital conversion does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Analog to digital conversion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Analog to digital conversion will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-896751