Linear electric motor controller and system for providing linear control

• US 20030057899A1
• Filed: 12/13/2001
• Published: 03/27/2003
• Est. Priority Date: 12/13/2001
• Status: Active Grant

• Current Assignee: 2112376 Ontario Limited (Carter Group, Inc.)
• Original Assignee: 2112376 Ontario Limited (Carter Group, Inc.)
• Inventors: LaCroix, Michael Charles
• Granted Patent: US 7,265,516 B2
• Time in Patent Office: Days
• US Class Current: 318/114
• CPC Class Codes: H02H 7/0822 Integrated protection, motor control centres
• CPC Class Codes: H02P 29/02 Providing protection against overload without automatic interruption of supply protection against faults of stepper motors H02P8/36

Abstract

The invention relates to a method of, and system for, linear speed control for an electric motor, in which a digital to analog converter means is used for converting an 8-bit digital signal to an analog voltage for setting voltage across a motor, a digital state machine means is used for converting the duty cycle of an input signal for output to the digital to analog converter means, and a closed loop feedback loop means is used for monitoring and setting the voltage across the motor. An over-current sense circuit can be used for monitoring the current across the electric motor. An over/under voltage sense circuit can be used for monitoring voltage of the electric motor. The resulting 8-bit digital control signal is converted to an analog voltage for the electric motor. Such methods and systems find particular use in automotive applications.

Claims

1. An electric motor linear speed controller, comprising:

a digital to analog converter means for converting an 8-bit digital signal to an analog voltage for setting voltage across a motor;

a digital state machine means for converting the duty cycle of an input signal for output to the digital to analog converter means; and

a closed loop feedback loop means for monitoring and setting the voltage across the motor.

2. The controller according to claim 1, further comprising an over-current sense circuit for monitoring the current across the electric motor.

3. The controller according to claim 1, further comprising an over/under voltage sense circuit for monitoring a supply voltage to the electric controller.

10. A system for controlling an electric automotive component comprising the component and the electric motor linear speed control of claim 1.

11. The system according to claim 10, wherein the component is an electric motor.

12. The system according to claim 10, wherein the component is an electric light.

13. The system according to claim 10, further comprising an over-current sense circuit for monitoring the current across the electric motor.

14. The system according to claim 10, further comprising an over/under voltage sense circuit for monitoring a supply voltage to the electric controller.

4. A circuit arrangement in a variable speed electric motor controller, comprising:

a controller logic circuit for operating a controller logic finite state machine, wherein the state machine sets the voltage supplied to an electric motor; and

a closed loop feedback for generating a signal indicating the voltage across the electric motor, the signal being input to the state machine for monitoring thereof.

5. The circuit arrangement of claim 4, wherein the state machine comprises at least a running state.

6. The circuit arrangement of claim 5, further comprising one or more of the following set of states:

a sleep state, a lockout state, an overcurrent state, a timeout state, or a battery check state.

7. The circuit arrangement of claim 4, wherein the controller logic circuit comprises a microprocessor and a memory, each configured for collectively controlling the state machine.

8. The circuit arrangement of claim 4, additionally comprising a digital to analog converter for converting an 8-bit digital signal to an analog voltage for setting the voltage supplied to the electric motor.

9. The circuit arrangement of claim 4, wherein the circuit arrangement is directly coupled with the electric motor.

15. A system for controlling the speed of an electric motor, the voltage across the electric motor determining the speed of the electric motor, the system comprising:

a digital to analog converter means, for converting a digital signal to analog voltage for setting a voltage across said electric motor;

a microprocessor and associated digital memory for generating the digital signal, said microprocessor configured to instantiate and operate a digital state machine for converting the duty cycle of an input signal generated by an associated closed loop feedback means; and

a closed loop feedback loop means, for monitoring the voltage across said motor and generating a signal for input to the microprocessor.

16. An automobile comprising the system of claim 15.

17. The automobile of claim 16, wherein the system comprises a temperature-control system.

18. A linear speed control for an automotive electric motor, comprising:

a digital state machine for converting the duty cycle of an input signal generated by an associated closed loop feedback;

an over-current sense circuit, for monitoring the current across said electric motor;

an over/under voltage sense circuit, for monitoring a supply voltage to the electric controller;

a digital to analog converter, for converting an 8-bit digital signal to analog voltage for setting voltage across said electric motor; and

a closed loop feedback loop, for monitoring the voltage across said motor and generating a signal for input to said digital state machine.