Identifying voltage to prevent motor integrated circuit damage

• US 10,158,308 B2
• Filed: 06/17/2016
• Issued: 12/18/2018
• Est. Priority Date: 06/17/2016
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Ogawa, Takashi, Kumazawa, Fumio, Yokoo, Satoshi, Uno, Juichi
• Primary Examiner(s): DUDA, RINA I
• Application Number:
  US15/186,050
• Publication Number:
  US 20170366122A1
• Time in Patent Office: 914 Days
• Field of Search: 318563, 318569, 318600, 3889075
• CPC Class Codes: H02P 29/024 Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load
• CPC Class Codes: H02P 29/0241 the fault being an overvoltage
• CPC Class Codes: H02P 7/03 for controlling the direction of rotation of DC motors
• CPC Class Codes: H02P 7/05 by means of electronic switching

Abstract

A motor control system, in some embodiments, comprises: a voltage divider circuit having an output node, a voltage on said output node representing a desired motor rotation direction; control logic configured to receive an indication of said voltage; and a motor controller coupled to the control logic, wherein, if said indication of the voltage on the output node falls outside of a predetermined range, the control logic is configured to issue a motor stop signal to the motor controller indicating that at least one resistor of the voltage divider circuit is defective or is missing from the voltage divider circuit.

Claims

1. A motor control system, comprising:

a control logic configured to receive an indication of a voltage detected at a node, said indication representing a desired motor rotation direction;

an analog-to-digital converter (ADC) positioned between said node said control logic;

a motor controller coupled to the control logic; and

a logical OR gate having a first input terminal coupled to the control logic, a second input terminal coupled to a pulse width modulation (PWM) logic, and an output terminal coupled to the motor controller, wherein if said voltage on the node falls outside of a predetermined range, the control logic is configured to issue a motor stop signal to the motor controller.

2. The system of claim 1, wherein said indication of the voltage is one of a predetermined number of digital bit values output by said ADC based on the voltage on said node.

3. The system of claim 2, wherein said predetermined number is sixteen.

4. The system of claim 3, wherein the control logic issues the motor stop signal if said indication of the voltage is one of the two highest or one of the two lowest of said sixteen digital bit values when the sixteen digital bit values are sorted in ascending order.

5. The system of claim 1, wherein said indication of the voltage is an analog voltage or a quantized digital bit value.

6. The system of claim 1, wherein the motor controller controls a car seat cooling fan in accordance with said motor stop signal.

7. The system of claim 1, wherein, if said indication falls within said predetermined range, the control logic issues a directional signal to the motor controller that indicates whether a motor should rotate clockwise or counter-clockwise.

8. The system of claim 1, wherein said predetermined range is the middle 75% of a defined set of possible values of said indication when said possible values are sorted in ascending order.

9. Non-transitory computer-readable medium storing instructions that, when executed by a processor, causes said processor to:

receive an indication of a voltage present at a node, said indication representing a desired motor rotation direction, and said indication received from an analog-to-digital converter (ADC) positioned between said node said processor;

determine whether said indication of the voltage falls outside a predetermined range; and

issue a motor stop signal if said indication of the voltage falls outside the predetermined range, wherein the processor is coupled to a first input terminal of a logical OR gate which has a second input terminal coupled to a pulse width modulation (PWM) logic and an output coupled to a motor controller.

10. The medium of claim 9, wherein said voltage at the node is configured to range between 0 and 5 Volts, and wherein said indication of the voltage at the node is a digital bit value selected from a range between 0000 and 1111, inclusive.

11. The medium of claim 10, wherein each digital bit value in said range of digital bit values is assigned to a corresponding analog voltage group, and wherein each analog voltage group falls within a range of possible voltages at the node.

12. The medium of claim 9, wherein said predetermined range is the middle 75% of a defined set of possible values of said indication.

13. The medium of claim 9, wherein the motor controller is a car seat cooling fan motor controller.

14. A method for controlling a motor, comprising:

obtaining an indication of a voltage present at a node, said indication received from an analog-to-digital converter (ADC) positioned between said node a control logic;

determining whether said indication of the voltage falls outside of a predetermined range;

issuing a motor stop signal if said indication of the voltage falls outside of the predetermined range, wherein said motor stop signal is provided to a first input terminal of a logical OR gate which has a second input terminal coupled to pulse width modulation (PWM) logic and an output terminal coupled to a motor controller; and

stopping a motor via the motor controller based on the motor stop signal.

15. The method of claim 14, further comprising quantizing said voltage present at the node to obtain said indication.

16. The method of claim 14, wherein said predetermined range corresponds to the middle 90% of a defined set of digital bit values.

17. The method of claim 14, further comprising rotating said motor in a direction determined using said indication.

18. The method of claim 14, wherein said motor is a car seat cooling fan motor.

19. The method of claim 14, wherein said indication is selected from a group of sixteen digital bit values.