MOTOR CONTROL METHOD

• US 20120086377A1
• Filed: 12/19/2011
• Published: 04/12/2012
• Est. Priority Date: 05/23/2008
• Status: Active Grant

• Current Assignee: Chung-Hung Tang, Chun-Lung Chiu, Ming-Shi Tsai, Po-Tsun Kuo
• Original Assignee: Chung-Hung Tang, Chun-Lung Chiu, Ming-Shi Tsai, Po-Tsun Kuo
• Inventors: CHIU, Chun-Lung, Tsai, Ming-Shi, Kuo, Po-Tsun, Tang, Chung-Hung
• Granted Patent: US 8,415,907 B2
• Time in Patent Office: Days
• US Class Current: 318/461
• CPC Class Codes: H02P 23/02 specially adapted for optimising the efficiency at low load

Abstract

A motor control apparatus and a motor control method determine whether the motor is in a back-pressure area so as to provide different rotation-speed control signals. When the fan is in the low duty cycle, a first circuit loop is switched on, so that the fan has more accurate rotation speed. When the fan is in the high duty cycle, a second circuit loop is switched on, so that the rotation speed of fan does not be limited to a constant rotation-speed as the fan enters the back-pressure area. Thus, the fan has larger airflow quantity and higher airflow pressure.

Claims

1. A motor control method, comprising steps of:

retrieving a rotation-speed sensing signal;

receiving a first rotation-speed control signal;

comparing the first rotation-speed control signal and a preset duty cycle value; and

when the first rotation-speed control signal is higher than the preset duty cycle value, generating a second rotation-speed control signal after calculating the first rotation-speed control signal and the rotation-speed sensing signal, wherein the second rotation-speed control signal is then outputted to drive a motor to generate magnetization so as to rotate a rotor of the motor.

2. The method according to claim 1, further comprising a step of:

when the first rotation-speed control signal is lower than the preset duty cycle value, outputting the first rotation-speed control signal to drive the motor to generate magnetization so as to rotate the rotor of the motor.

3. The method according to claim 1, wherein the preset duty cycle value is a duty cycle threshold value of a fan entering a back-pressure area.

4. The method according to claim 1, wherein the first rotation-speed control signal and the second rotation-speed control signal are both duty cycle signals.

5. The method according to claim 1, wherein the rotation-speed sensing signal is inputted from an outside of an motor control apparatus.

6. The method according to claim 1, wherein the rotation-speed sensing signal is retrieved by a sensing unit when a sensing unit detects the rotor of the motor.

7. The method according to claim 1, wherein the step of comparing the first rotation-speed control signal and the preset duty cycle value is performed by a judging unit or a speed control unit.

8. The method according to claim 1, wherein the step of generating the second rotation-speed control signal after calculating the first rotation-speed control signal and the rotation-speed sensing signal is performed by a rotation-speed weighting unit or a speed control unit.

9. The method according to claim 1, wherein the second rotation-speed control signal is a rotation speed of the rotor entering a back-pressure area, or the second rotation-speed control signal is generated according to equations of:

T₂=T₁+S

S=(S₁/S_Full)*k

wherein S_Full is a full speed of the motor;

S₁ represents the rotation-speed sensing signal;

S is a weighted rotation speed;

T₁ represents the first rotation-speed control signal;

T₂ represents the second rotation-speed control signal; and

k is a constant.