Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – Frequency of cyclic current or voltage
Patent
1975-03-10
1977-02-01
Corcoran, Robert J.
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
Frequency of cyclic current or voltage
G01R 3312
Patent
active
040064077
ABSTRACT:
Automatic balancing circuits are provided for non-destructive testing systems such as eddy current systems in which an unbalance of a probe circuit including a test coil produces undesired deviations from a null indication. Error signal components are generated from a probe circuit output signal, stored in storage means and then applied in a balancing direction to cancel the effect of the unbalance of the probe circuit. Preferably, the error signal components are generated by a pair of quadrature phase detectors and the storage means comprises either a capacitor or the combination of digital storage and digital-analog converter means. The balancing is performed either automatically, with a delay in the storage operation, or by operation of a switch means between a sample or null condition in which the error signals are stored and a hold condition in which the stored error signals are applied. In one embodiment, the stored error signals are used to modulate AC signal components in quadrature phase relation which are applied in a balancing direction. In another, the stored error signals are developed from phase detector output signals and then combined therewith. In both embodiments, balancing signals are combined with signals derived from the probe circuit output signal and applied at points preceding high gain amplification in signal processing circuitry.
REFERENCES:
patent: 2914726 (1959-11-01), Harmon
patent: 3278839 (1966-10-01), Wells et al.
patent: 3532980 (1970-10-01), Tucker
patent: 3566258 (1971-02-01), Mori et al.
patent: 3763424 (1973-10-01), Bennett, Jr.
patent: 3794915 (1974-02-01), Wolfinger
Doll et al.; Vehicle Mounted Mine Detector; Electronics; Jan. 1946; pp. 105-109.
Cohen et al.; Self Balancing System Etc.; IEEE Trans. on Bio-Medical Eng.; vol. BME-18; No. 1; Jan. 1971; pp. 66-69.
Flaherty John J.
Strauts Eric J.
Corcoran Robert J.
Magnaflux Corporation
LandOfFree
Non-destructive testing systems having automatic balance and sam does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Non-destructive testing systems having automatic balance and sam, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-destructive testing systems having automatic balance and sam will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1093441