Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – Frequency of cyclic current or voltage
Patent
1980-10-27
1983-09-27
Krawczewicz, Stanley T.
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
Frequency of cyclic current or voltage
324133, 361 93, G01R 3102
Patent
active
044069855
ABSTRACT:
An inductance coil is clamped onto the cable which is to be monitored. For normal line currents, the coil produces a signal voltage which charges a reset capacitor which in turn periodically discharges to an indicator to show a no fault condition. When the line current goes above a predetermined fault level and remains at that level for a corresponding fault time period, the coil develops a signal voltage sufficiently high to charge a "set" capacitor that discharges to the indicator to show a fault condition. The indicator continues to show the fault condition until normal current has returned to cause the "reset" circuit to operate to indicate no fault. To insure that the set capacitor discharges in a manner to indicate reliably the fault condition, there is provided a voltage responsive variable impedence in the circuitry to charge the set capacitor. This variable impedence matches the fuse characteristic in the main power line.
REFERENCES:
patent: 3304490 (1967-02-01), Dubin et al.
patent: 3512045 (1970-05-01), Tipton et al.
patent: 3573556 (1971-04-01), Zocholl
patent: 3735248 (1973-05-01), Reese
patent: 3777217 (1973-12-01), Groce
patent: 3991366 (1976-11-01), Schweitzer, Jr.
Buxton James L.
Phillips Alan C.
City of Seattle, The City Light Dep't.
Krawczewicz Stanley T.
LandOfFree
Power cable fault finding apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power cable fault finding apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power cable fault finding apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2131831