Wide-range logarithmic responding translation circuit
US3971984A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 4, 1974 |
| Grant date | Jul 27, 1976 |
| Priority date | — |
| Expiry date | Sep 4, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06G7/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosed circuit provides a wideband, wide-range logarithmic responding voltmeter particularly suitable for use as a transducer analyzer. The circuit includes an input for receiving a given A.C. input signal which can vary within a 100 db dynamic range. The input signal is coupled to a buffer amplifier the output of which is capacitively coupled to a logarithmic converter. The converter includes an operational amplifier and provides an A.C. output signal which is proportional to the logarithm of its A.C. input signal. The open loop gain of the operational amplifier is utilized to provide the A.C. output signal. The output signal of the converter is capacitively coupled to a precision AC/DC converter which rectifies and filters the output signal to provide a D.C. output voltage the level of which is, therefore, also proportional to the logarithm of the given A.C. input signal within its 100 db range. The D.C. output voltage is coupled to utilization means such as a logarithmically calibrated chart recorder or meter. The precision AD/DC converter also includes a zero-adjustment for nulling any offsets in its circuit and any residual noise at the output of the logarithmic convert…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.