Zeroing circuit
US3955139A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1974 |
| Grant date | May 4, 1976 |
| Priority date | — |
| Expiry date | Jul 15, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/16585
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Baseline drift and noise can produce difficulties in registering signals quantitatively without recourse to frequent rezeroing of the registering instrument. The invention provides a circuit in which the registering instrument only functions when a required signal is to be noted, the instrument at all other times being at a zero reading. The characteristics of a signal to be registered will be known. The circuit includes a differentiator which notes the rate of change of incoming signals and operates a switching device upon detecting a required rate of change to enable the signal to pass to the registering instrument. At all other times the registering instrument is isolated by the switching device. A comparator circuit can also be included to measure the magnitude of the signals which have the required rate of change as determined by the differentiator and to prevent the passage of signals to the registering instrument which fail to reach a predetermined magnitude, for example a magnitude of 10% of full scale deflection of the registering instrument.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.