Circuit for providing a controlled resistance
US4728881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1987 |
| Grant date | Mar 1, 1988 |
| Priority date | — |
| Expiry date | Feb 19, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06G7/62
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for providing a controlled resistance, the circuit comprising a pair of terminals for input of an excitation current, variable resistance means connected in the current path between the terminals, means for deriving a first signal representing the value of the voltage appearing across the terminals, means for deriving a second signal representing the value of the excitation current, means for generating a third signal representing a selected value of resistance to be provided between the pair of terminals, means for comparing the ratio of the first and second signals with the value of the third signal to derive a difference signal, and means for applying the difference signal to cause the variable resistance means to change in value such that said ratio tends towards exact equality with the selected value of resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.