Input circuit for electronic instruments
US4277749A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1979 |
| Grant date | Jul 7, 1981 |
| Priority date | — |
| Expiry date | Feb 21, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R15/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An input circuit for electronic instruments, particularly measuring instruments, has an input for an input signal with a DC and an AC component and has an output for connection to the electronic instrument. A direct current or direct voltage source is provided, and a compensating circuit compensates the DC component of the input signal in such a way that the AC component is isolated and presented at the output. The compensating circuit is basically an impedance network consisting of three resistors connected in a .pi.-style with the two outer resistors being connected to direct voltage or direct current sources which are jointly variable in such a way that they cancel each other at the input and the DC component of the input signal can be compensated at the output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.