Meter drive circuit
US4442549A · kind A · utility
9Cited by
10References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 27, 1982 |
| Grant date | Apr 10, 1984 |
| Priority date | — |
| Expiry date | May 27, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J3/14
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit and method for producing a signal the magnitude of which varies with the logarithm of an input signal supplied to a plurality of cascaded differential amplifier stages each having substantially equal gain. As particular ones of the stages go into limiting the DC rectified voltage produced at the differential common node of each of the stages is detected to produce a plurality of currents. These currents are summed to the input of a current turn-around circuit which produces the signal at an output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.