Circuit arrangement for controlling a rotary-magnet measuring instrument
US4748406A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 16, 1986 |
| Grant date | May 31, 1988 |
| Priority date | — |
| Expiry date | Sep 16, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R15/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit arrangement for controlling a rotary-magnet measuring instrument (6) by an input voltage via a controlled source of current has a first amplifier (difference amplifier 1) with a first negative-feedback resistor (R.sub.2) and a first input resistor (R.sub.1). In order to linearize the approximately S-shaped characteristic curve of the rotary-magnet measuring instrument (6), the controlled source of current is developed with a characteristic curve which is defined as consisting of three straight line segments of differing slope. For this, a second amplifier (difference amplifier 8), controlled as a function of the input voltage and a semiconductor path controlled by it (2nd npn-transistor 12) which lies in series with the first input resistor (R.sub.1) are provided. One input (10) of the second amplifier is connected to a constant voltage divider (divider resistors R.sub.3, R.sub.5) and via a second negative-feedback resistor (R.sub.4), to the controlled semiconductor path and the first input resistor (at point Y). The resistances of the second negative feedback resistor (R.sub.4) and of the constant voltage divider (divider resistors R.sub.3 , R.sub.5) are small as compare…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.