Dynamic motor drive for battery operated devices

Patent metadata

Field	Value
Publication number	US-10305403-B2
Application number	US-201615198054-A
Country	US
Kind code	B2
Filing date	Jun 30, 2016
Priority date	Feb 16, 2016
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

A battery powered device includes a battery and a motor controller that is coupled to the battery. A motor is operably coupled to the motor controller. The motor controller is configured to detect an amount of available power from the battery and engage the motor based on the amount of available power.

First claim

What is claimed is:

1. A process variable measurement device comprising:
a visual indicator configured to indicate a process variable measurement output;
a battery;
a motor controller coupled to the battery;
a motor operably coupled to the visual indicator and electrically coupled to the motor controller, and
wherein the motor controller is configured to detect an amount of available power from the battery and engage the motor based on the amount of available power.

2. The process variable measurement device of claim 1 , wherein the motor controller is configured to convert bulk motor movement into a series of block movements and cause at least one block of movement in the motor and then assess a voltage of the battery before causing a subsequent block of movement.

3. The process variable measurement device of claim 1 , further comprising a power detection component coupled to the battery, wherein the power detection component is configured to provide an indication of the voltage of the battery to the motor controller.

4. The process variable measurement device of claim 3 , wherein the power detection component comprises a low voltage detector circuit.

5. The process variable measurement device of claim 1 , wherein the motor is a stepper motor.

6. The process variable measurement device of claim 1 , and further comprising a bulk capacitance component operably coupled to the battery, wherein the bulk capacitance component is configured to store a portion of available power from the battery.

7. The process variable measurement device of claim 4 , wherein the bulk capacitance component comprises at least one bulk capacitor operably coupled to the battery to assist driving the motor.

8. The process variable measurement device of claim 3 , wherein the motor controller is configured to compare the indication of the voltage of the battery to a minimum voltage threshold to determine whether there is sufficient power available to engage the motor.

9. The process variable measurement device of claim 8 , wherein the motor controller determines that there is insufficient power available to engage the motor and, in response, is configured to generate at least one block movement.

10. The battery-powered device of claim 1 , wherein the motor controller is configured to engage the motor based on the amount of available power such that the motor controller prevents the process variable measurement from resetting.

11. The process variable measurement device of claim 1 and further comprising a wireless transceiver configured to transmit signals in a process environment.

12. A method of dynamically controlling a motor for a measuring device, comprising:
detecting an amount of available power from a battery by using a power detection component;
analyzing the amount of available power to determine whether there is a sufficient amount of power to engage a motor;
coupling a bulk capacitance component to the motor controller wherein the bulk capacitance component is configured to store energy received from the battery;
wherein the motor controller is configured to use the stored energy in the bulk capacitance component to move the motor a finite amount;
assessing the position of the motor to determine whether the motor is at a desired position; and
determining that the motor is not at the desired position and, in response, generating instructions with the motor controller, wherein the instructions instruct a motor control component to move the motor a subsequent finite amount to indicate a process variable.

13. The method of claim 12 , wherein analyzing the amount of available power comprises analyzing with a motor controller.

Assignees

• Rosemount Inc

Inventors

• Lovegren Eric Russell
• Nelson Richard Louis

Classifications

• H02K37/00

  Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors · CPC title

• H02P29/00 Primary

  Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors (arrangements for starting electric motors H02P1/00; arrangements for stopping or slowing electric motors H02P3/00; control of motors that can be connected to two or more different electric power supplies H02P4/00; regulating or controlling the speed or torque of two or more electric motors H02P5/00; vector control H02P21/00) · CPC title

• G01L19/16

  Dials; Mounting of dials · CPC title

• H02P8/16 Primary

  Reducing energy dissipated or supplied · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title