Bridge pulse controlled constant current driver for magnetic flowmeter
US5372045A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1993 |
| Grant date | Dec 13, 1994 |
| Priority date | — |
| Expiry date | Feb 12, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic flowmeter system provides a volumetric flow rate output and has a coil receiving a magnetic field producing coil current from the current supply circuitry. The current supply circuitry includes an H-bridge transistor circuit having first and second switches which couple one of the first and second coil wires to a supply conductor. Third and fourth switches of the bridge circuit couple the other of the first and second coil wires to a second supply conductor. A control circuit periodically alternates conduction of the first, second, third and fourth switches to reverse the polarity of the coil current. A coil current control circuit generates a non-alternating output representing the sensed alternating coil current amplitude. The control circuit modulates the conduction duty cycle of the third and fourth switches as a function of the non-alternating output to regulate the coil current amplitude to a selected level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.