Device for measuring a physical quantity
US4960000A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 1989 |
| Grant date | Oct 2, 1990 |
| Priority date | — |
| Expiry date | Oct 27, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D3/036
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention concerns a device for measuring a physical quantity, for example a force (A), and providing an output signal (Vs) whose amplitude represents the measured value. The device comprises a first oscillator (1) including a resonator (3) to which the force (A) is applied, this oscillator delivering a first alternating signal (S1) whose frequency depends on the magnitude of the force (A), a second oscillator (2) supplying a second alternating signal (S2) whose frequency is determined by the amplitude of the output signal (Vs), an EXCLUSIVE OR gate (20) receiving the first and second signals, and a low-pass filter (21) delivering the output signal (Vs) in response to a signal supplied by the gate (20). The amplitude of this output signal depends on the phase difference of the first and second signals, and constitutes a measurement of the magnitude of the applied force (A). The device is advantageously used when the measurement is to be displayed in analog form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.