Wide range current flow fault detector
US4032766A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 1976 |
| Grant date | Jun 28, 1977 |
| Priority date | — |
| Expiry date | May 17, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/15
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A wide range current flow fault detector comprising a current sensor and a selective interrogator are disclosed. Current flow, or the lack thereof, between a power supply (e.g., capacitor bank) and a load (e.g, the hammer coils of a line printer) is sensed by a current sensor connected to detect the voltages at spaced points along a selected length of the supply conductor connecting the power supply to the load. A differential amplifier forming a part of the current sensor produces an output voltage related to the voltage difference between the selected points. The output voltage of the differential amplifier is compared, in a comparator, with a preset voltage. Any time the output voltage of the differential amplifier is above the preset voltage, the output of the comparator changes from a first state (e.g., low) to a second state (e.g., high). At all other times, the output of the comparator remains in the first state. Thus, the output state of the comparator denotes the presence or absence of current flow through the supply conductor adequate to cause the output of the differential amplifier to rise above the preset level. The interrogator selectively interrogates the output of t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.