التفاصيل البيبلوغرافية
| العنوان: |
MANAGEMENT APPARATUS OF A ROTATING MOTOR AND AN ANNEXED LOAD DURING POWER LOSS |
| Document Number: |
20120161678 |
| تاريخ النشر: |
June 28, 2012 |
| Appl. No: |
13/330410 |
| Application Filed: |
December 19, 2011 |
| مستخلص: |
A management apparatus is described of a rotating motor and a load during power loss; the apparatus comprises a first switching circuit coupled with the rotating motor and a controller of said first switching circuit. The controller is configured to drive the first switching circuit so as to convert a back-electromotive force voltage developed in the rotating motor into a power supply voltage for the load. The first switching circuit is driven in accordance with a first duty cycle. The apparatus comprises a second switching circuit coupled with the load and driven in accordance with a second duty cycle. The controller is configured to vary said first and said second duty cycles to keep the power supply voltage for the load above or equal to a threshold voltage. |
| Inventors: |
Maiocchi, Giuseppe (Capiago Intimiano, IT); Galbiati, Ezio (Agnadello, IT) |
| Assignees: |
STMicroelectronics S.r.l. (Agrate Brianza, IT) |
| Claim: |
1. A management apparatus for controlling a rotating motor and a load during power loss, said apparatus comprising: a first switching circuit configured to be coupled with the rotating motor; a second switching circuit configured to be coupled with the load; and a controller configured to control said first and second switching circuits, cause said first switching circuit to convert a back-electromotive force voltage of the rotating motor into a power supply voltage for the load, drive said first switching circuit in accordance with a first duty cycle and drive the second switching circuit in accordance with a second duty cycle, and vary said first and said second duty cycles to keep said power supply voltage for the load above or equal to a threshold voltage. |
| Claim: |
2. An apparatus according to claim 1, wherein said controller is configured to control the first and the second switching circuits and to perform a synchronous rectification of said back-electromotive force voltage. |
| Claim: |
3. An apparatus according to claim 1, wherein said controller is configured to: force the first duty cycle equal to one at an initial instant of power loss, said compare said power supply voltage with said threshold voltage; decrease, by a prefixed value, said first duty cycle each time the power supply voltage decreases below the threshold voltage; and set the second duty cycle as a function of the first duty cycle. |
| Claim: |
4. An apparatus according to claim 3, wherein said controller is configured to set the second duty cycle as a function of the first duty cycle in accordance with the following equation: [mathematical expression included] where D1 is the first duty cycle, Vbemf indicates the back-electromotive force voltage of the rotating motor, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D2 is the second duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
5. An apparatus according to claim 1, wherein said controller includes a comparator configured to compare said power supply voltage with said threshold voltage and the controller is configured to: force the first duty cycle and the second duty cycle equal to 1 at an initial instant of power loss; decrease, by a prefixed value, said first duty cycle each time the power supply voltage decreases below the threshold value until arriving at a first duty cycle value; after arriving at the first duty cycle value, decrease, by a prefixed value, said second duty cycle each time the power supply voltage decreases below the threshold voltage until a minimum value of the second duty cycle is achieved; and set the first duty cycle as a function of the second duty cycle. |
| Claim: |
6. An apparatus according to claim 5, wherein said controller is configured to set the first duty cycle as a function of the second duty cycle in accordance with the following relation: [mathematical expression included] where D2 is the second duty cycle, Vbemf indicates the back-electromotive force voltage of the rotating motor, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D1 is the first duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
7. An apparatus according to claim 5, wherein said first duty cycle value is given by: [mathematical expression included] where Vbemf indicates the back-electromotive force voltage, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D1opt is the first duty cycle value, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
8. An apparatus according to claim 1, wherein: said first switching circuit includes a first half-bridge that includes first and second transistors coupled between a power supply voltage terminal, configured to receive said power supply voltage, and ground ; and said second switching circuit includes: a second half-bridge that includes third and fourth transistors coupled between the power supply terminal and ground; and a third half-bridge that includes fifth and sixth transistors coupled between the power supply terminal and ground, the fifth transistor being configured to be always turned off, the sixth transistor being configured to be always turned on, the second and the third half-bridges having respective center points configured to be coupled to the load. |
| Claim: |
9. A system, comprising: a rotatable motor a first switching circuit coupled to the rotatable motor; a second switching circuit configured to be coupled with a load; and a controller configured to control said first and second switching circuits in accordance with first and second duty cycles, respectively, cause said first switching circuit to convert a back-electromotive force voltage in the rotatable motor into a power supply voltage for the load, and vary said first and said second duty cycles to keep said power supply voltage for the load above or equal to a threshold voltage. |
| Claim: |
10. A system according to claim 9, wherein said controller is configured to control the first and the second switching circuits and to perform a synchronous rectification of said back-electromotive force voltage. |
| Claim: |
11. A system according to claim 9, wherein said controller is configured to: force the first duty cycle equal to one at an initial instant of power loss, said compare said power supply voltage with said threshold voltage; decrease, by a prefixed value, said first duty cycle each time the power supply voltage decreases below the threshold voltage; and set the second duty cycle as a function of the first duty cycle. |
| Claim: |
12. A system according to claim 11, wherein said controller is configured to set the second duty cycle as a function of the first duty cycle in accordance with the following equation: [mathematical expression included] where D1 is the first duty cycle, Vbemf indicates the back-electromotive force voltage of the rotating motor, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D2 is the second duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
13. A system according to claim 9, wherein said controller includes a comparator configured to compare said power supply voltage with said threshold voltage and the controller is configured to: force the first duty cycle and the second duty cycle equal to 1 at an initial instant of power loss; decrease, by a prefixed value, said first duty cycle each time the power supply voltage decreases below the threshold value until arriving at a first duty cycle value; after arriving at the first duty cycle value, decrease, by a prefixed value, said second duty cycle each time the power supply voltage decreases below the threshold voltage until a minimum value of the second duty cycle is achieved; and set the first duty cycle as a function of the second duty cycle. |
| Claim: |
14. A system according to claim 13, wherein said controller is configured to set the first duty cycle as a function of the second duty cycle in accordance with the following relation: [mathematical expression included] where D2 is the second duty cycle, Vbemf indicates the back-electromotive force voltage of the rotating motor, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D1 is the first duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
15. A system according to claim 13, wherein said first duty cycle value is given by: [mathematical expression included] where Vbemf indicates the back-electromotive force voltage, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D1opt is the first duty cycle value, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
16. A system according to claim 9, wherein: said first switching circuit includes a first half-bridge that includes first and second transistors coupled between a power supply voltage terminal, configured to receive said power supply voltage, and ground ; and said second switching circuit includes: a second half-bridge that includes third and fourth transistors coupled between the power supply terminal and ground; and a third half-bridge that includes fifth and sixth transistors coupled between the power supply terminal and ground, the fifth transistor being configured to be always turned off, the sixth transistor being configured to be always turned on, the second and the third half-bridges having respective center points configured to be coupled to the load. |
| Claim: |
17. A system according to claim 9, wherein said motor is a hard disk spindle motor and said load is a voice coil motor. |
| Claim: |
18. A management method for controlling a rotating motor and a load during power loss, said method comprising: converting a back-electromotive force voltage of the rotating motor into a power supply voltage for the load; driving a first switching circuit, coupled with the rotating motor, in accordance with a first duty cycle; driving a second switching circuit, coupled to the load, in accordance with a second duty cycle; and keeping said power supply voltage for the load above or equal to a threshold voltage by varying said first and second duty cycles. |
| Claim: |
19. A method according to claim 18, wherein driving the first switching circuit and driving the second switching circuit include performing a synchronous rectification of said back-electromotive force voltage. |
| Claim: |
20. A method according to claim 18, comprising: forcing the first duty cycle equal to one and making the second duty cycle be a function of the first duty cycle at an initial instant of power loss; successively comparing said power supply voltage with said threshold voltage; successively decreasing, by a prefixed value, said first duty cycle each time the power supply voltage decreases below the threshold voltage; and setting the second duty cycle again as a function of the first duty cycle until a minimum value of the first duty cycle is achieved or the power off ends. |
| Claim: |
21. A method according to claim 20, wherein setting the second duty cycle as a function of the value of the first duty cycle includes setting the second duty cycle in accordance with the following equation: [mathematical expression included] where D1 is the first duty cycle, Vbemf indicates the back-electromotive force voltage, R1 and R2 are equivalent resistances of the rotating motor and the load, respectively, D2 is the second duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
22. A method according to claim 18, comprising, in succession: forcing the first and the second duty cycles equal to 1 at an initial instant of power loss; comparing said power supply voltage with said threshold voltage; decreasing, by a prefixed value, said first duty cycle each time the power supply voltage decreases below the threshold value until a first duty cycle value is obtained; after obtaining the first duty cycle value, decreasing, by a prefixed value, said second duty cycle each time the power supply voltage decreases below the threshold voltage; and setting the first duty cycle as a function of the second duty cycle until a minimum value of the second duty cycle is achieved or the power loss ends. |
| Claim: |
23. A method according to claim 22, wherein setting the first duty cycle as a function of the second duty cycle occurs in accordance with the following relation: [mathematical expression included] where D2 is the second duty cycle, Vbemf indicates the back-electromotive force voltage, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D1 is the first duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
24. A method according to claim 22, wherein said first duty cycle value is given by: [mathematical expression included] where Vbemf indicates the back-electromotive force voltage, R1 and R2 are equivalent resistances of the rotating motor and of the load, respectively, D1opt is the first duty cycle, and Invc is a current indicating current dissipated by further electronic devices connected to the load. |
| Claim: |
25. A method according to claim 18, wherein said rotating motor is a hard disk spindle motor and said load is a voice coil motor. |
| Current U.S. Class: |
318/150 |
| Current International Class: |
02 |
| رقم الانضمام: |
edspap.20120161678 |
| قاعدة البيانات: |
USPTO Patent Applications |
