Preamplifier for voltage measuring instrument with non-interacting zero and span controls
US4315211A · kind A · utility
4Cited by
5References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 3, 1980 |
| Grant date | Feb 9, 1982 |
| Priority date | — |
| Expiry date | Mar 3, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/68
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A preamplifier circuit for a voltage measuring instrument which provides for noninteracting span and zero adjustments. Two voltage follower circuits are used. The first produces a current through the output resistor of the preamplifier proportional to the voltage being measured while the second produces a current through the output resistor proportional to a fixed reference voltage. For both amplifiers, the proportionality is adjustable by a potentiometer which modifies the feedback on the first amplifier and the part of the reference used as input to the second amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.