Load leveling boost supply for magnetic flowmeter

Patent metadata

Field	Value
Publication number	US-2021072055-A1
Application number	US-201916727357-A
Country	US
Kind code	A1
Filing date	Dec 26, 2019
Priority date	Sep 5, 2019
Publication date	Mar 11, 2021
Grant date	—

Abstract

A magnetic flowmeter for measuring a fluid flow includes a flow tube assembly receiving the flow and having a coil with first and second coil wires for receiving a coil current and responsively producing a magnetic field thereby generating an EMF in the fluid representative of a flow rate. An EMF sensor is arranged to sense the EMF and generate an output indicating the flow rate. Current supply circuitry applies a current supply signal to the coil. A load leveling boost supply provides power to the current supply circuitry. In another aspect, power scavenging circuitry recovers power from the coil.

First claim

What is claimed is:

1 . A magnetic flowmeter for measuring a fluid flow, comprising:
a flow tube assembly receiving the flow having a coil with first and second coil wires for receiving a coil current and responsively producing a magnetic field thereby generating an EMF in the fluid representative of a flow rate; an EMF sensor arranged to sense the EMF and generate an output indicating the flow rate; current supply circuitry configured to apply a current supply signal to the coil; and a load leveling boost supply configured to provide power to the current supply circuitry and condition the input current from a DC source to be nearly constant.

2 . The magnetic flowmeter of claim 1 wherein the current supply circuitry includes first and second switches which couple the first and second coil wires respectively to a first supply conductor, and third and fourth switches which couple the first and second coil wires respectively to a second supply conductor.

3 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply includes a power storage element configured to scavenge power from the coil when a direction of the current supply signal through the coil is reversed.

4 . The magnetic flowmeter of claim 3 wherein the power storage element comprises a capacitor.

5 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply includes a current sensor configured to sense current flowing into the coil and responsively control the current supply signal based upon the sensed current.

6 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply includes a current sensor configured to sense current flowing out of the coil and responsively control the current supply signal based upon the sensed current.

7 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply includes current sense circuitry configured to sense a difference between a current flowing into the coil and a current flowing out of the coil and responsively control the current supply signal based upon the sensed current difference.

8 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply senses a voltage related to a voltage across the coil and responsively controls the current supply signal based upon the sensed voltage.

9 . The magnetic flowmeter of claim 8 wherein the load leveling boost supply determines a difference between a current flowing in to the coil and a current flowing out of the coil and further responsively controls the current supply signal based upon this difference.

10 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply is coupled to an input voltage and is configured to apply a voltage to the coil which is greater than the input voltage.

11 . The magnetic flowmeter of claim 10 wherein the load leveling boost supply includes a switch configured to selectively couple an inductor to electrical ground and thereby generate the voltage which is greater than the input voltage.

12 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply includes a diode to prevent current from the coil from flowing into components of the load leveling boost supply when a direction of the current supply signal applied to the coil is reversed.

13 . The magnetic flowmeter of claim 1 wherein the load leveling boost supply includes a voltage sensor to sense a back EMF flowing from the coil into the load leveling boost supply due to a reversal in a direction of the current supply signal flowing through the coil.

14 . The magnetic flowmeter of claim 13 wherein the load leveling boost supply includes a switch configured to control the current supply signal as a function of the sensed back EMF.

15 . A magnetic flowmeter for measuring a fluid flow, comprising:
a flow tube assembly receiving the flow having a coil with first and second coil wires for receiving a coil current and responsively producing a magnetic field thereby generating an EMF in the fluid representative of a flow rate; an EMF sensor arranged to sense the EMF and generate an output indicating the flow rate; current supply circuitry configured to apply a current supply signal to the coil; and power scavenging circuitry configured to recover power from the coil.

16 . The magnetic flowmeter of claim 15 wherein the power scavenging circuitry includes a power storage element.

17 . The magnetic flowmeter of claim 16 wherein the power storage element comprises a capacitor.

18 . The magnetic flowmeter of claim 15 including load leveling boost supply having a current sensor configured to sense current flowing into the coil and responsively control the current supply signal based upon the sensed current.

19 . The magnetic flowmeter of claim 15 including load leveling boost supply having a current sensor configured to sense current flowing out of the coil and responsively control the current supply signal based upon the sensed current.

20 . The magnetic flowmeter of claim 15 wherein the load leveling boost supply includes a switch configured to shut off the current supply signal as a function of the sensed back EMF.

Assignees

• Micro Motion Inc

Inventors

• Hunter Kirk Allan
• Dreier Jared James

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• G01F1/60 Primary

  Circuits therefor · CPC title

• G01F15/066

  involving magnetic transmission devices · CPC title

• G01F1/586 Primary

  constructions of coils, magnetic circuits, accessories therefor (G01F1/582 takes precedence; magnet; inductances; transformers; selection of materials for their magnetic properties per se H01F) · CPC title

• H02J7/0068

  Electricity · mapped topic