CN101997476A - Motor drive device and drive method thereof - Google Patents

Abstract

A motor driving device comprises a control unit and an output unit, wherein the control unit is connected with a control signal and sends the control signal to the output unit after processing the control signal, and the motor driving device is characterized in that: the control unit comprises a noise filtering device, the noise filtering device enables the control unit to enter a restarting state according to a second set time, and enables the control unit to send a control signal to the output unit according to a third set time so as to drive a motor.

Description

Motor drive device and drive method thereof

technical field

The present invention relates to a drive device for a single-phase motor, in particular to a drive device capable of preventing erroneous start caused by noise. A noise filter circuit controls the start signal of the motor to prevent erroneous start caused by noise. drive unit.

Background technique

In recent years, with the rapid development of personal computers (Personal Computer, PC), portable computers (Portable Computer/Note-Boob, NB) or workstations (Work Station), the operation speed of computing chips has increased rapidly, such as: central Processing unit (Central Processor Unit, CPU), digital signal processor (Digital Signal Processor, DSP). Therefore, as the operating speed of the chip increases, the frequency also increases, causing the chip to generate a large amount of heat. However, high heat can cause the following problems: cause the chip to operate abnormally, or have an impact on surrounding circuits. Therefore, the cooling function of the chip becomes an extremely important technology.

Generally speaking, as the cooling method for this type of computing chip, a mature fan (Fan) is used for cooling. For example, the speed of the fan is controlled to send cool air to the surface of the chip to remove heat. However, when the motor that drives the fan to dissipate heat is rotating, there will be the following two situations that cause the motor to stop rotating; During normal rotation (so-called deadlock-locked), excessive current will flow through the motor coil and semiconductor components, which may damage the motor. In order to deal with the above problems, the US Publication No. 20080315808 patent application discloses a lock protection circuit 32 to monitor the hysteresis output state of the Hall component, so that after the motor deadlock is determined, the power supply to the motor coil can be stopped immediately, As shown in Figure 1. On the other hand, another reason that will cause the motor to stop is that the system (for example: the central processing unit of a portable computer) provides a control signal (V _cnt ) that requires "motor to stop", for example: the control signal that controls the motor to rotate The PWM signal becomes a low potential signal (Low), that is, the control output stage 24 immediately stops energizing the motor coil; the purpose of this method is to save energy consumption. Therefore, when the lock protection circuit detects that the PWM signal is a low-level signal and keeps it for a period of time, there may be external noise in the control signal (V _cnt ) provided by the system to control the "motor stops rotating", causing the chip to generate The wrong action causes the motor to rotate again, making the system unable to achieve the purpose of saving energy.

Contents of the invention

The object of the present invention is to provide a motor driving device and method to solve the defects in the known technology.

In order to achieve the above object, the motor drive device provided by the present invention includes a control unit and an output unit, and the control unit is connected to a control signal and processed to send the control signal to the output unit, wherein the motor drive device is characterized in that: The control unit includes a noise filter device, the noise filter device makes the control unit enter the restart state according to a second set time, and then makes the control unit send the control signal to the output unit according to a third set time, Used to drive a motor.

The motor driving method provided by the present invention, wherein: provide a control signal to a motor driving device, the control signal is a PWM signal; provide an oscillating device, the oscillating device is configured in the motor driving device to generate an initial time and a Noise judgment time; provide a noise filtering device to receive the control signal and judge whether the duration of the low potential of the PWM signal is greater than the initial time; initialize a control device, when the duration of the low potential of the PWM signal is greater than the initial time, control The device enters a waiting state according to the output signal of the noise filter device; judging the state of a start signal, the pulse cycle of the start signal is judged by the noise filter device, and when the pulse cycle of the start signal is greater than the noise judgment time, the start signal will be output to an output unit.

The motor drive device equipped with noise filtering function provided by the present invention is used to judge whether the control signal is noise, so as to solve the problem in the prior art that the chip causes erroneous actions due to noise.

In the motor drive chip equipped with a noise filtering device provided by the present invention, the noise filtering device judges whether the control signal is noise, so as to reduce erroneous actions of the chip.

The motor drive chip equipped with a noise filtering device provided by the present invention is used to achieve the purpose of saving energy.

The motor drive chip configured with the noise filtering device provided by the present invention enables the motor drive chip to stop driving the motor according to the instruction of the control signal.

The motor drive chip configured with the noise filtering device provided by the present invention can drive the motor according to the instruction of the control signal, so that the fan rotates to achieve the purpose of heat dissipation.

Description of drawings

Fig. 1 is a schematic circuit block diagram of a chemical technology;

Fig. 2 is a schematic circuit block diagram of a preferred embodiment of the present invention;

Fig. 3 is the waveform diagram of each node in Fig. 2 of the present invention;

Fig. 4 is a schematic diagram of the restart waveform of the present invention.

Explanation of main component symbols in the drawings

Motor drive device 10; control unit 100; Hall bias voltage 110; hysteresis device 120; control device 130; anti-deadlock judging device 140; counting device 150; ; output unit 200 ; output circuit 210 / 220 ; Hall element 20 ; resistor 21 / 22 ; control signal (V _cnt ) 30 ; motor 40 .

Detailed ways

The present invention discloses a motor drive chip equipped with a noise filter device and its driving method, especially the motor drive chip is equipped with a noise filter device, and the noise filter device judges whether the control signal is noise, so as to reduce chip malfunction. However, since the motor output unit circuit mentioned in the present invention is the same as that used in the known technology, the detailed circuit of the motor output unit is not shown in the figure. In addition, the drawings in the following texts are not completely drawn according to the actual relevant dimensions, and their function is only to express the schematic diagrams related to the features of the present invention.

First please refer to FIG. 2 , which is a schematic diagram of the motor driving device of the present invention. As shown in Figure 2, the motor drive device 10 includes a control unit 100 and an output unit 200; wherein the control unit 100 is composed of a Hall bias 110, a hysteresis device 120, a control device 130, an anti-deadlock judgment Device 140, a counting device 150, an oscillating device 160 and a noise filtering device 170. When the control signal 30 provides a high-potential PWM driving signal, the high-potential PWM driving signal will pass through the control device 130 in the control unit 100 to send the PWM driving signal to the output unit 200, and the slave PWM driving signal The output drive voltage is used to control the coil current in the output unit 200 (i.e., to pass current) to control the motor 40 to start rotating; then, the Hall element 20 on the motor 40 will send the commutation signal of the motor 40 to the hysteresis device 120 and the output unit 200 are used to determine whether the motor 40 is continuously rotating. It should be noted here that the motor 40 of the present invention can be a single-phase full-wave motor, but it can also be a three-phase motor; when the motor 40 of the present invention is a three-phase motor, the 2 is only a schematic diagram of one phase of a three-phase motor.

Next, the operation process of the motor driving device of the present invention will be described in detail according to FIG. 2 and FIG. 3 .

First, please refer to Figure 2 and Figure 3 at the same time. When the control signal (V _cnt ) 30 provides a PWM driving signal; the PWM driving signal is formed by alternating pulse waves between high level and low level, as shown by V _cnt in FIG. 3 ; then the PWM driving signal will pass through the control device 130 in the control unit 100 to send the PWM driving signal to the output unit 200, and the output unit 200 is controlled to output current to the motor 40 by the high level voltage output from the PWM driving signal The middle coil (not shown in the figure) is used to control the motor 40 to start rotating. Next, the first terminal of the Hall element 20 is connected to the power supply line to which the Hall bias voltage 110 is applied via the resistor 21 , and the second terminal thereof is grounded via the resistor 22 . The Hall component 20 can output the Hall signal V _H1 from the first output end and the Hall signal V _H2 from the second output end, and the levels of the two output signals change with the position of the rotor of the motor 40 . When the motor 40 rotates, the Hall signal V _H1 and the Hall signal V _H2 are out of phase with each other and the period follows the rotation speed of the motor 40 to form a sine wave; and when this sine wave passes through the hysteresis device 120, it will form Rectangular wave, for example, when the hysteresis device 120 compares the Hall signal V _H1 output from the Hall component 20 with the Hall signal V _H2 line, when V _H1 > V _H2 , the hysteresis device 120 outputs a high-level rectangular wave signal, when V _H1 <V _H2 , the output of the hysteresis device 120 is a low-level rectangular wave signal.

Next, connect the rectangular wave signal (shown as NODE A in FIG. 3 ) output by the hysteresis device 120 to the counting device 150, so that the counting device 150 counts the switching states of the high level and low level of the rectangular wave signal. When the counting device 150 has a high-level and low-level conversion within a first set time (for example, 500us-500ms), it means that the motor 40 is in a state of normal operation; A signal of a low level is sent to the anti-deadlock judging device 140 , so that the anti-deadlock judging device 140 also sends a low-level signal to the control device 130 . At this time, the control device 130 will send the high-level PWM driving signal to the output unit 200, and the output circuit 210 and the output circuit 220 are controlled by the high-level driving voltage output from the PWM driving signal to provide current to the coil on the motor 40. To drive the motor 40 to rotate.

In addition, when the counting device 150 can only count to a high level or a low level within the first set time (that is, it means that the rectangular wave signal output by the hysteresis device 120 is a high level or a low level), it means that the motor 40 The phase of OUT1 and OUT2 does not change, as shown in the period from "motor deadlock" to "deadlock detection" of OUT1 and OUT2 in Figure 3. Obviously, at this moment, the motor 40 is in a state of stopping rotation. At this time, the counting device 150 will send a signal of this state (such as sending a high-level signal) to the anti-deadlock judging device 140, so that the anti-deadlock judging device 140 also sends a high-level signal to the control device 130; Then, the control device 130 will send a low-level signal to the output unit 200, so that the output circuit 210 and the output circuit 220 are closed, so no current will be provided to the coil on the motor 40, so the motor can be stopped immediately to prevent the motor from 40 In the deadlock state, the output circuit 210 and the output circuit 220 still pass too much current, which causes an irrecoverable failure of the motor.

After processing by the system, if the counting device 150 can count the change of the level within the first set time, it means that the motor 40 is already in the state of normal operation, and the control device 130 will turn the high-potential PWM The driving signal is sent to the output unit 200 to drive the motor 40 to continue rotating.

Next, if the system wants to save energy, it can choose to change the PWM signal provided by the control signal (V _cnt ) 30 to a low voltage, as shown in the waveform diagram of V _cnt in FIG. 4 . Therefore, the control device 130 will also send a low-level signal to the output unit 200, so that the output circuit 210 and the output circuit 220 are closed, so no current is provided to the coil on the motor 40, so the motor 40 stops rotating immediately.

Then, the motor 40 will keep in the state of stopping rotation until the system selectively changes the PWM signal provided by the control signal (V _cnt ) 30 to a high potential. At this time, the high potential PWM signal will provide current to the coil on the motor 40 to make the motor 40 rotate again. After the motor 40 rotates again, the counting device 150 judges that the motor 40 is in the state of normal operation within the first set time; to the anti-deadlock judging device 140 , so that the anti-deadlock judging device 140 also sends a low-level signal to the control device 130 . Then, the control device 130 will send the high-level PWM driving signal to the output unit 200, and the output circuit 210 and the output circuit 220 are controlled by the high-level driving voltage output from the PWM driving signal to provide current to the coil on the motor 40, so that The motor 40 is controlled to rotate.

Similarly, if the counting device 150 can only count to the high level or the low level within the first set time after a period of time after the motor is restarted, it means that the phase of the motor 40 has not changed, and then, it will be as In the foregoing process, the anti-deadlock judging device 140 sends a high-level signal to the control device 130; and the control device 130 sends a low-level signal to the output unit 200, so that the output circuit 210 and the output circuit 220 are closed, Therefore, no current will be provided to the coils on the motor 40, so the motor can be stopped immediately, so as to prevent the motor 40 from being in a deadlock state, the output circuit 210 and the output circuit 220 still pass too much current, causing the motor to generate irrecoverable damage. Fault.

Obviously, in the above process, the PWM driving signal provided by the control signal (V _cnt ) 30 is the main signal for controlling the rotation or stopping of the motor 40; when the PWM driving signal provided by the control signal (V _cnt ) 30 is When the potential is high (that is, it is actually formed by a pulse wave alternately transformed between a high level and a low level, such as V _cnt in FIG. 3 ), the control device 130 will send a high potential PWM driving signal to the output unit 200. The high-level driving voltage output by the PWM driving signal controls the output circuit 210 and the output circuit 220 to provide current to the coil on the motor 40 to control the rotation of the motor 40 . And when the PWM driving signal provided by the control signal (V _cnt ) 30 is changed to a low potential (such as V _cnt in FIG. 4 ), the control device 130 will close the output circuit 210 and the output circuit 220 in the output unit 200, so No current is supplied to the coils on the motor 40, so the motor 40 remains in a state of stopping rotation. When the PWM driving signal provided by the control signal (V _cnt ) 30 changes to a high potential again, the control device 130 will send the high potential PWM driving signal to the output unit 200 so that current can flow through the coil on the motor 40 , to restart the motor 40 to rotate again.

Next, please refer to FIG. 4 , when the PWM driving signal transmitted by the control signal (V _cnt ) 30 remains at a low level for more than a specific time, for example: a second set time (T _ini ), the control signal ( The PWM driving signal transmitted by V _cnt ) 30 enters the noise filter device 170 . When the PWM drive signal transmitted by the control signal (V _cnt ) 30 enters the noise filter device 170, the noise filter device 170 will judge whether the PWM drive signal is a high potential or a low potential according to the second set time (for example, 0.05 seconds); The second set time may also be referred to as an initial time (T _ini ). Next, when the PWM driving signal provided by the control signal (V _cnt ) 30 is continuously at a low potential, it is obvious that the noise filter device 170 does not count the high level and the low level of the high potential within the initial time (T _ini ). If the pulse wave is quasi-interchangeable, the noise filtering device 170 will determine that the PWM drive signal is a low-level signal; in other words, when the time exceeds the initial time (T _ini ) and there is still no high-level signal, the motor at this moment has stopped turn. At this time, the system will initialize the control device 130 . The so-called initialization means that the control device 130 is preset in a state of waiting for restart. The timing diagram after the control device 130 enters the initial state is shown in Figure 4, the power supply (V _cc ) will be at a high potential, and the Hall bias (HB) will be charged to a preset potential at the same time, and the system will wait for the PWM drive After the signal becomes a high potential, the motor 40 is restarted immediately.

When the PWM driving signal provided by the control signal (V _cnt ) 30 changes from a low potential to a high potential, the high potential signal will be sent to the noise filter device 170 at the same time. At this time, the noise filtering device 170 will enter another counting time (or called the third setting time), and the third setting time can be selected to be less than the pulse width of each high level or low level of the PWM driving signal (for example: 20us), and the noise filtering device 170 will judge whether the incoming high potential signal is noise or a PWM driving signal according to the third set time. When the pulse width of the high-potential signal entering the noise filter device 170 is less than the third set time, the noise filter device 170 will judge it as a noise and filter it out; when the pulse width of the high-potential signal entering the noise filter device 170 is greater than During the third setting time, the noise filtering device 170 will judge that it is a PWM driving signal, and therefore will output a signal (for example, send a low-level signal) to the control device 130 immediately. At this time, the control device 130 will send the high-potential PWM driving signal to the output unit 200 according to the aforementioned operation method, and the output circuit 210 and the output circuit 220 will be controlled by the driving voltage output from the PWM driving signal to provide current to the motor 40. The coil to control the motor 40 to start again. It should be emphasized here that when the system enters the restart state, it is obvious that the noise filter device 170 will first judge whether the incoming high potential signal is noise, and will send out the signal after judging that the PWM driving signal is high potential to the control device 130; therefore, after the system enters the initialization state and enters the state of waiting for restart, when the high potential signal enters the noise filter device 170, the control device 130 will delay a third set time before restarting The motor 40 is shown as OUT1/OUT2 in FIG. 4 . This function of firstly judging whether the high potential is noise by the noise filter device 170 can effectively prevent the control signal (V _cnt ) 30 from being disturbed by abnormal noise and start the motor 40 by mistake. The noise interference may be caused by external factors or too long wires used for control signals.

As shown in FIG. 4 again, when the PWM driving signal provided by the control signal (V _cnt ) 30 changes from a high potential to a low potential, and when the low potential time exceeds the initial time (T _ini ) of the second set time , the system will initialize the control device 130 again to wait for restart.

In addition, it will be explained again that the counting device 150 and the noise filtering device 170 in FIG. . Therefore, the oscillator 160 can provide the above-mentioned first set time, second set time and third set time.

In addition, the motor drive device 10 of the present invention may further include a thermal shutdown (Thermal Shut Down; TSD) circuit 180; or an over-current (over-current) circuit 180, so that the motor drive chip 10 has better protection function. Since the thermal shutdown (TSD) circuit and the over-current circuit are known technologies, they will not be described again.

Furthermore, the motor driving device 10 of the present invention can be integrated into one chip. However, the motor driving device 10 of the present invention may also be composed of a chip formed by the control unit 100 and a chip formed by the output unit 200 .

Based on the above description, the present invention then provides a motor driving method. First, the system provides a control signal (V _cnt ) 30 to a motor drive device 10. The control signal 30 can be a PWM signal; then, an oscillation device is provided 160. The oscillation device 160 is arranged in the motor drive device 10 and connected to a noise filter device 170 to generate a second set time (or called initial time-T ini ) and a third set time (or called initial time-T _ini ) and a third set time (or called noise judgment time); then, a noise filter device 170 is provided, and the noise filter device 170 is configured in the motor drive device 10 for receiving the control signal (V _cnt ) 30 and judging the PWM signal of the control signal (V _cnt ) 30 Whether the duration of the low potential is greater than the initial time; when the noise filter device 170 judges that the low potential duration of the PWM signal is greater than the initial time, the control device 130 will be initialized so that the control device 130 enters a Waiting for the starting state; then, after the control device 130 enters the starting state, when the PWM signal of the control signal (V _cnt ) 30 changes from a low potential to a high potential, the noise filtering device 170 will judge the pulse cycle of the high potential When the pulse period of the start signal is greater than the noise judgment time, the start signal is output to an output unit 200 to drive the motor 40 to rotate; if the pulse period of the start signal is less than the noise judgment time, the high potential signal is regarded as noise and filtered out.

As mentioned above, the present invention has described the preferred embodiment of the motor driver chip 10 in detail, the main purpose of which is to clarify the embodiment of the present invention so that those skilled in the art can implement it, and it is not intended to limit the precise application form of the present invention . Therefore, it is possible for those skilled in the art to make certain modifications based on the above teachings and suggestions or learning from the embodiments of the present invention. Therefore, the technical idea of the present invention will be determined by the scope of the claims of the application and their equivalents.

Claims (10)

1. A motor drive device, comprising a control unit and an output unit, the control unit is connected with a control signal and processed to send the control signal to the output unit, wherein the motor drive device is characterized in that: The control unit includes a noise filter device, the noise filter device makes the control unit enter the restart state according to a second set time, and then makes the control unit send the control signal to the control unit according to a third set time The output unit is used to drive a motor. 2. The motor driving device as claimed in claim 1, wherein the second set time is after the PWM signal changes from a high potential to a low potential, and then maintains the low potential for a set time. 3. The motor driving device as claimed in claim 1, wherein the third set time is shorter than the pulse period of the control signal. 4. A motor drive device, comprising a control unit and an output unit, the control unit is connected with a control signal and processed to send the control signal to the output unit, and the control unit is composed of a hysteresis device, It consists of a control device, an anti-deadlock judging device, a counting device, an oscillating device and a noise filtering device, wherein the motor drive device is characterized by: The noise filtering device makes the control unit enter the restart state according to a second set time, and then makes the control unit send the control signal to the output unit according to a third set time to drive a motor . 5. The motor driving device as claimed in claim 4, wherein the second set time is after the PWM signal changes from a high potential to a low potential, and then maintains the low potential for a set time. 6. The motor driving device as claimed in claim 4, wherein the third set time is shorter than the pulse period of the control signal. 7. The motor driving device as claimed in claim 4, wherein the counting device is connected with the hysteresis device, and judges the output state of the hysteresis device according to a first set time. 8. The motor driving device as claimed in claim 4, wherein the motor driving device is a chip. 9. The motor driving device as claimed in claim 4, wherein each of the control unit and the output unit is a chip. 10. A motor driving method, characterized in that: Provide a control signal to a motor drive device, the control signal is a PWM signal; provide an oscillating device, the oscillating device is configured in the motor drive device to generate an initial time and a noise judgment time; Provide a noise filter device, the noise filter device is configured in the motor drive device and connected to the oscillation device, for receiving the control signal and judging whether the duration of the low potential of the PWM signal is longer than the initial time; Initialize a control device, the control device is configured in the motor drive device and connected to the noise filter device, when the low potential duration of the PWM signal is longer than the initial time, the control device will be based on the output signal of the noise filter device enter a waiting state; Judging the state of an activation signal, the noise filtering device determines the pulse period of the activation signal, and outputs the activation signal to an output unit when the pulse period of the activation signal is greater than the noise judgment time.

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