Motor controller
Patent Information
- Application Number
- TW114109815
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2026-10-01
- Estimated Expiration
- 2045-03-16
AI Technical Summary
Existing motor controllers face issues with excessive braking current leading to transistor or motor coil burnout due to fully conductive transistor systems, and inability to control or adjust generated braking current.
A motor controller with a switching circuit and control circuit that uses transistors in partial conductivity modes and adjusts braking current through varying on-resistance, preventing overvoltage conditions.
The solution allows for controlled and adjustable braking current, preventing transistor and motor coil damage by maintaining transistors within safe operating ranges.
Smart Images
Figure TWG2TA001077464_001 
Figure TWG2TA001077464_002
Abstract
Description
Technical Field
[0001] This invention relates to a motor controller, and more particularly to a motor controller applicable to a single-phase motor or a three-phase motor. The motor controller may be a fan motor controller. Prior Technology
[0002] Traditionally, motor controllers can have a braking function to stop a motor. However, when the motor controller enters braking mode, the transistor system in the full-bridge circuit is driven in a fully conductive manner. At this time, the on-resistance of the transistors may be too small, resulting in excessive braking current, which may burn out the transistors or motor coils. In addition, when the transistor system is driven in a fully conductive manner, the motor controller will be unable to control and adjust the generated braking current.
[0003] Therefore, a new technology is needed to solve the above problems. Summary of the Invention
[0004] In view of the aforementioned problems, the object of the present invention is to provide a motor controller that can control and adjust a braking current.
[0005] According to the present invention, a motor controller is provided. According to one embodiment of the present invention, the motor controller has a switching circuit and a control circuit. The switching circuit may have a first transistor, a second transistor, a third transistor, a fourth transistor, a first terminal, a second terminal, a third terminal, and a fourth terminal. The switching circuit is coupled to a motor coil. The first transistor is coupled to the first terminal and the third terminal, and the second transistor is coupled to the second terminal and the third terminal. The third transistor is coupled to the first terminal and the fourth terminal, and the fourth transistor is coupled to the second terminal and the fourth terminal. The control circuit generates a first control signal, a second control signal, a third control signal, and a fourth control signal to control the first transistor, the second transistor, the third transistor, and the fourth transistor, respectively.
[0006] When the motor controller enters a braking mode, an induced electromotive force causes a braking current to flow through the motor coil. At this time, the control circuit can partially conduct the first transistor. The control circuit can also partially conduct the second transistor. The control circuit can operate the first transistor in a first linear region. The control circuit can operate the second transistor in a second linear region. Furthermore, the control circuit can deactivate the third and fourth transistors to prevent the braking current from flowing back to the fourth terminal and causing an overvoltage condition. When the motor controller enters the braking mode, the control circuit can adjust the braking current to an adjustable value by varying the first on-resistance of the first transistor or the second on-resistance of the second transistor. For example, when the motor controller enters the braking mode, the control circuit can gradually change the first control signal from a first low voltage to a first high voltage, making the braking current a controllable value to avoid burning out the first transistor, the second transistor, or the motor coil. When the motor controller enters the braking mode, the control circuit can also gradually change the second control signal from a second low voltage to a second high voltage, wherein the first low voltage can be equal to the second low voltage and the first high voltage can be equal to the second high voltage. Finally, by making the braking current the adjustable value, the control circuit can achieve a power control effect, ensuring that both the first transistor and the second transistor operate within a safe range.
[0007] This motor controller can be applied to a single-phase motor, a three-phase motor, a DC motor, or a brushless motor. Additionally, it can be used as a fan motor controller. Simple Explanation of the Diagram
[0008] Figure 1 is a schematic diagram of a motor controller according to an embodiment of the present invention. Implementation
[0009] The objects, features, and advantages of the invention will become more apparent from the following description. Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings.
[0010] Figure 1 is a schematic diagram of a motor controller 10 according to an embodiment of the present invention. The motor controller 10 has a switching circuit 100 and a control circuit 110. The switching circuit 100 may have a first transistor 101, a second transistor 102, a third transistor 103, a fourth transistor 104, a first terminal O1, a second terminal O2, a third terminal GND, and a fourth terminal VCC. The switching circuit 100 is coupled to a motor coil L to drive a motor. The first transistor 101 is coupled to the first terminal O1 and the third terminal GND, while the second transistor 102 is coupled to the second terminal O2 and the third terminal GND. The third transistor 103 is coupled to the first terminal O1 and the fourth terminal VCC, while the fourth transistor 104 is coupled to the second terminal O2 and the fourth terminal VCC. The first transistor 101 and the second transistor 102 may each be an N-type metal-oxide-semiconductor (MOSFET). The third transistor 103 and the fourth transistor 104 may each be a P-type MOSFET. The first transistor 101 and the second transistor 102 can each be a lower bridge switch. The third transistor 103 and the fourth transistor 104 can each be an upper bridge switch. The control circuit 110 generates a first control signal C1, a second control signal C2, a third control signal C3, and a fourth control signal C4 to control the first transistor 101, the second transistor 102, the third transistor 103, and the fourth transistor 104, respectively. Furthermore, the fourth terminal VCC can have an input voltage, which can be a power supply voltage. The third terminal GND can have a ground voltage. The system can provide an input voltage to the motor controller 10 via the fourth terminal VCC, enabling the motor controller 10 to operate normally. For example, the input voltage can be 12 volts and the ground voltage can be 0 volts. Therefore, the motor controller 10 can be applied in a high-voltage configuration.
[0011] When the motor controller 10 enters a braking mode, an induced electromotive force Vbemf is generated, causing a braking current Ibr to flow through the motor coil L. At this time, the control circuit 110 can make both the first transistor 101 and the second transistor 102 partially conductive. That is, the control circuit 110 can make the first transistor 101 operate in a first linear region and the second transistor 102 operate in a second linear region. Of course, the designer can also design that only one of the first transistor 101 and the second transistor 102 is partially conductive; this invention does not require that both the first transistor 101 and the second transistor 102 be partially conductive. That is, the designer can also design that only one of the first transistor 101 and the second transistor 102 operates in a linear region. In addition, the control circuit 110 can make both the third transistor 103 and the fourth transistor 104 non-conductive to prevent the braking current Ibr from flowing back to the fourth terminal VCC and causing an overvoltage condition. When the motor controller 10 enters braking mode, the control circuit 110 can adjust the braking current Ibr to an adjustable value by modulating the first on-resistance of the first transistor 101 or the second on-resistance of the second transistor 102. For example, when the motor controller 10 enters braking mode, the control circuit 110 can gradually change the first control signal C1 from a first low voltage to a first high voltage, making the braking current Ibr a controllable value to avoid burning out the first transistor 101, the second transistor 102, or the motor coil L. When the motor controller 10 enters braking mode, the control circuit 110 can also gradually change the second control signal C2 from a second low voltage to a second high voltage, where the first low voltage can be equal to the second low voltage and the first high voltage can be equal to the second high voltage. Finally, by making the braking current Ibr an adjustable value, the control circuit 110 can achieve a power control effect, ensuring that both the first transistor 101 and the second transistor 102 operate within a safe range.
[0012] The control circuit 110 may include a digital-to-analog converter 111, which provides a first DC voltage to a first control signal C1 and a second DC voltage to a second control signal C2. The digital-to-analog converter 111 may be an N-bit digital-to-analog converter, where N is a positive integer and N is greater than or equal to 2. For example, N may be equal to 6. The larger one of the values in the digital-to-analog converter 111, the larger the first DC voltage or the second DC voltage can be. The first DC voltage may be between a first low voltage and a first high voltage. The second DC voltage may also be between a second low voltage and a second high voltage. That is, the control circuit 110 may modulate the first control signal C1 and the second control signal C2 via the digital-to-analog converter 111 to make the braking current Ibr adjustable. Furthermore, the designer may design other circuits to replace the function of the digital-to-analog converter 111. Therefore, the digital-to-analog converter 111 is not an essential feature of this invention.
[0013] The motor controller 10 can be applied to a single-phase motor, a three-phase motor, a DC motor, or a brushless motor. Furthermore, the motor controller 10 can be a fan motor controller to drive a fan motor. According to the disclosed technology, when the motor controller 10 enters braking mode, the control circuit 110 can make the braking current Ibr adjustable.
[0014] While the invention has been described by way of example with reference to preferred embodiments, it should be understood that the invention is not limited to the embodiments disclosed herein. Rather, the invention is intended to cover various modifications and similar configurations that will be apparent to those skilled in the art. Therefore, the scope of the claim should be interpreted in the broadest sense to include all such modifications and similar configurations. The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent application of the present invention shall be covered by the present invention.
[0015] 10: Motor controller 100: Switching circuit 101: First Transistor 102: Second transistor 103: Third transistor 104: Fourth Transistor 110: Control Circuit 111: Digital-to-Analog Conversion Circuit O1: First endpoint O2: Second endpoint GND: Third Endpoint VCC: Fourth Endpoint C1: First control signal C2: Second control signal C3: Third control signal C4: Fourth control signal L: Motor coil Vbemf: Induced electromotive force Ibr: Braking current
Claims
1. A motor controller comprising: a switching circuit coupled to a motor coil, wherein the switching circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a first terminal, a second terminal, a third terminal, and a fourth terminal, the first transistor being coupled to the first terminal and the third terminal, the second transistor being coupled to the second terminal and the third terminal, the third transistor being coupled to the first terminal and the fourth terminal, and the fourth transistor being coupled to the second terminal and the fourth terminal; and a control circuit generating a first control signal, a second control signal, a third control signal, and a fourth control signal for controlling the first transistor, the second transistor, the third transistor, and the fourth transistor, respectively, wherein when the motor controller enters a braking mode, the control circuit modulates a first on-resistance of the first transistor or a second on-resistance of the second transistor to make a braking current an adjustable value.
2. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes the first transistor to be partially turned on.
3. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes the second transistor to be partially turned on.
4. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes the first transistor to operate in a first linear region.
5. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes the second transistor to operate in a second linear region.
6. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes both the third transistor and the fourth transistor to be de-conducting.
7. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes the first control signal to gradually change from a first low voltage to a first high voltage.
8. The motor controller as described in claim 1, wherein when the motor controller enters the braking mode, the control circuit causes the second control signal to gradually change from a second low voltage to a second high voltage.
9. The motor controller as described in claim 1, wherein the control circuit achieves a power control effect by making the braking current the adjustable value, thereby ensuring that both the first transistor and the second transistor operate within a safe range.
10. The motor controller as described in claim 1, wherein the control circuit includes a digital-to-analog converter circuit for providing a first DC voltage to the first control signal and providing a second DC voltage to the second control signal.
11. The motor controller as described in claim 10, wherein the digital-to-analog conversion circuit is an N-bit digital-to-analog converter, where N is a positive integer and N is greater than or equal to 2.
12. The motor controller as described in claim 1, wherein the control circuit includes a digital-to-analog converter circuit, the control circuit modulating the first control signal and the second control signal via the digital-to-analog converter circuit so that the braking current is the adjustable value.
13. The motor controller as described in claim 12, wherein the digital-to-analog conversion circuit is an N-bit digital-to-analog converter, where N is a positive integer and N is greater than or equal to 2.
14. The motor controller as described in claim 1, wherein the first transistor and the second transistor are each an N-type metal-oxide-semiconductor.
15. The motor controller as described in claim 1, wherein the third transistor and the fourth transistor are each a P-type metal-oxide-semiconductor.
16. The motor controller as described in claim 1, wherein the first transistor and the second transistor are each a lower bridge switch.
17. The motor controller as described in claim 1, wherein the third transistor and the fourth transistor are each an upper bridge switch.
18. The motor controller as described in claim 1, wherein the motor controller is applied to a high-voltage configuration.
19. The motor controller as described in claim 1, wherein the motor controller is applied to a single-phase motor.
20. The motor controller as described in claim 1, wherein the motor controller is applied to a three-phase motor.
21. The motor controller as described in claim 1, wherein the motor controller is applied to a DC motor.
22. The motor controller as described in claim 1, wherein the motor controller is applied to a brushless motor.
23. The motor controller as described in claim 1, wherein the motor controller is a fan motor controller.