Motor driver adopting gradient driving mechanism

Abstract

The invention discloses a motor driver adopting a gradual change type driving mechanism. The motor driver includes a gradient drive setting circuit, a gradient waveform construction circuit, and a motor driving circuit. The gradual change driving setting circuit outputs a gradual change driving setting signal which gradually changes along with time. The gradual change driving setting signal is provided with a plurality of different gradual change driving setting voltages which are respectively set at a plurality of setting time points. The gradient waveform construction circuit sets a plurality of waveforms of a gradient waveform signal according to a plurality of gradient drive setting voltages. A plurality of duty ratios of a plurality of waveforms of the gradient waveform signal are different from each other. The motor driving circuit drives the motor according to the gradient waveform signal.

Description

Technical Field

[0001] This invention relates to electric motors, and more particularly to an electric motor driver employing a gradual drive mechanism. Background Technology

[0002] Electronic products generate heat during operation, especially in enclosed housings or other confined spaces. The heat generated by each circuit component circulates within the housing, heating other components and potentially causing overheating and damage. Therefore, electronic products must be equipped with fans to cool the circuit components. During cooling, once the circuit components have cooled below a critical temperature, the motor speed can be appropriately reduced.

[0003] Multiple fans are often installed inside electronic devices such as servers to cool processors and other heat-generating components. When these fans operate, hot air is blown outwards from the electronic device, thereby reducing its internal temperature. However, when a fan is removed due to damage or replacement, the airflow reverses direction, flowing back into the space where the fan was originally located. This causes a new fan to reverse direction when it is installed, often at a very high speed, requiring a strong braking method to prevent this. Traditional motor drives, however, fail to effectively and precisely control the motor braking of the fans.

[0004] However, when using a traditional electric motor for braking, the conventional braking method of fully opening the lower bridge switch and fully closing the upper bridge switch sometimes fails to completely stop the motor due to insufficient braking force. Conversely, if one upper bridge switch is kept open for an extended period to increase braking force, it can sometimes cause excessive braking current flowing through the motor, leading to overcurrent damage. For example, when the return air around the motor is low, the back electromotive force of the motor is small, and keeping one upper bridge switch open for an extended period will result in excessive current; conversely, when the return air around the motor is high, not keeping one upper bridge switch open for an extended period will result in insufficient braking force to stop the motor. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a motor driver employing a gradual drive mechanism. The motor driver of this invention includes a gradual drive setting circuit, a gradual waveform construction circuit, and a motor drive circuit. The gradual drive setting circuit is configured to output a gradual drive setting signal that varies over time. The gradual drive setting signal has multiple different gradual drive setting voltages set at multiple set time points. The gradual waveform construction circuit is connected to the gradual drive setting circuit. The gradual waveform construction circuit is configured to set multiple waveforms of a gradual waveform signal based on the multiple gradual drive setting voltages at the multiple set time points in the gradual drive setting signal. The multiple duty cycles of the multiple waveforms of the gradual waveform signal are different from each other. The motor drive circuit is connected to the gradual waveform construction circuit and a motor. The motor drive circuit is configured to output a gradual drive signal to the motor based on the gradual waveform signal.

[0006] According to the present invention, the motor driver employing a gradual drive mechanism brakes the motor and gradually changes the braking speed of the motor over time.

[0007] According to the present invention, the motor driver employing a gradual drive mechanism includes a gradual waveform construction circuit comprising a comparison circuit configured to compare a gradual drive setting voltage set at each set time point with an oscillating voltage to output a gradual waveform signal.

[0008] According to the present invention, the motor driver employing a gradual drive mechanism further includes: an oscillation circuit connected to a gradual waveform construction circuit, configured to output an oscillation waveform signal having multiple oscillation waveforms; wherein, the gradual waveform construction circuit uses multiple voltages on the multiple oscillation waveforms as multiple oscillation voltages, and compares the gradual drive setting voltages set at multiple set time points with the multiple oscillation voltages to set multiple duty cycles of the multiple waveforms of the gradual waveform signal.

[0009] According to the present invention, the motor driver employing a gradual drive mechanism includes multiple oscillation waveforms of the oscillation waveform signal, which include multiple triangular wave waveforms, multiple sawtooth wave waveforms, or combinations thereof.

[0010] According to the present invention, the motor driver employing a gradual drive mechanism connects the gradual drive setting voltage of each of a plurality of setting time points with the gradual drive setting voltage of the next setting time point in a gradual drive setting image segment. The plurality of gradual drive setting image segments between the plurality of setting time points are connected to each other to generate a gradual drive setting image. The gradual drive setting circuit outputs a gradual drive setting signal according to the gradual drive setting image.

[0011] According to the present invention, the motor driver employing a gradual drive mechanism compares the gradual drive setting voltage set at each set time point on the gradual drive setting image with an oscillation voltage to set multiple duty cycles of multiple waveforms of the gradual waveform signal.

[0012] According to the present invention, the motor driver employing a gradual drive mechanism compares multiple voltages at multiple non-set time points on the gradual drive setting image with multiple oscillating voltages to set multiple duty cycles of multiple waveforms of the gradual waveform signal.

[0013] According to the present invention, the motor driver employing a gradual drive mechanism sets the slope of the gradual drive setting image based on a drive demand information.

[0014] According to the present invention, the motor driver employing a gradual drive mechanism sets multiple slopes of multiple gradual drive setting image segments based on multiple drive demand information within multiple time intervals.

[0015] According to the present invention, the motor driver employing a gradual drive mechanism constructs a ladder-shaped waveform image in the gradual drive setting signal. The ladder-shaped waveform image has multiple ladder segments, the height of each ladder segment is the gradual drive setting voltage, and the multiple widths of the multiple ladder segments are multiple time lengths.

[0016] According to the present invention, the motor driver employing a gradual drive mechanism further includes: a speed detection circuit connected to the motor drive circuit, configured to detect the gradual drive signal, and to infer the motor speed based on the detected gradual drive signal to output a motor speed detection signal.

[0017] According to the present invention, the motor driver employing a gradual drive mechanism modulates the output of a gradual drive signal to the motor based on the motor speed detection signal.

[0018] According to the present invention, when the motor speed is not less than a certain speed threshold, the motor drive circuit brakes the motor.

[0019] According to the present invention, when the motor speed is less than the speed threshold, the motor drive circuit stops and brakes the motor.

[0020] According to the present invention, the electric motor driver employing a gradual drive mechanism has a critical speed value of zero.

[0021] According to the present invention, the electric motor driver employing a gradual drive mechanism is a three-phase electric motor or a single-phase electric motor.

[0022] As described above, the present invention provides a motor driver employing a gradual driving mechanism. The motor driver of the present invention uses a gradual driving mechanism to provide progressive braking force to the motor, appropriately controlling the current flowing through the motor, particularly when braking the motor, to prevent damage to the motor due to overcurrent. For example, when the return air around the motor is strong, the motor driver of the present invention increases the braking current flowing through the motor to achieve complete braking; conversely, when the return air around the motor is weak, the motor driver of the present invention reduces the braking current flowing through the motor to achieve braking while preventing damage to the motor due to overcurrent.

[0023] To further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings. However, the drawings provided are for illustrative purposes only and are not intended to limit the scope of the invention. Attached Figure Description

[0024] Figure 1 This is a block diagram of a motor driver employing a gradual drive mechanism according to the first embodiment of the present invention.

[0025] Figure 2 This is a block diagram of a motor driver employing a gradual drive mechanism according to a second embodiment of the present invention.

[0026] Figure 3 This is a block diagram of a motor driver employing a gradual drive mechanism according to a third embodiment of the present invention.

[0027] Figure 4 This is a circuit diagram of the comparison circuit included in the gradual waveform construction circuit of the motor driver employing a gradual drive mechanism according to the fourth embodiment of the present invention.

[0028] Figure 5 The waveform diagram shows the signal of the motor driver employing a gradual drive mechanism according to the fifth embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram of the duty cycle versus time curve of the gradually changing waveform signal of the motor driver employing a gradually changing drive mechanism according to the sixth embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram of multiple curves of the duty cycle versus time of the gradually changing waveform signal of the motor driver employing a gradually changing drive mechanism according to the seventh embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of the motor speed versus time curve detected by the motor driver employing a gradual drive mechanism according to the eighth embodiment of the present invention.

[0032] Figure 9 The waveform diagram shows the signal of the motor driver employing a gradual drive mechanism according to the ninth embodiment of the present invention.

[0033] Figure 10 The waveform diagram shows the signal of the motor driver employing a gradual drive mechanism according to the tenth embodiment of the present invention. Detailed Implementation

[0034] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" as used herein may, depending on the actual situation, include any combination of any one or more of the associated listed items.

[0035] Please see Figure 1 This is a block diagram of a motor driver employing a gradual drive mechanism according to the first embodiment of the present invention.

[0036] like Figure 1 As shown, in the first embodiment, the motor driver of the present invention includes a gradual drive setting circuit 10, a gradual waveform construction circuit 20, and a motor drive circuit 30. The gradual waveform construction circuit 20 is connected to the gradual drive setting circuit 10 and the motor drive circuit 30. The motor drive circuit 30 is connected to a motor MT. The motor MT described herein may be a motor of a fan or other electronic device. The motor MT described herein may be a three-phase motor or a single-phase motor.

[0037] First, the gradual drive setting circuit 10 outputs a gradual drive setting signal that varies with time, such as gradually increasing or decreasing as the time length increases. This gradual drive setting signal has multiple different gradual drive setting voltages set at multiple setting time points.

[0038] Next, the gradient waveform construction circuit 20 sets the duty cycle of multiple waveforms of a gradient waveform signal DTS based on multiple gradient drive setting voltages in a gradient drive setting signal WBS received from the gradient drive setting circuit 10, wherein the duty cycle of the waveform generated later is larger or smaller. That is, the duty cycle of the multiple waveforms of the gradient waveform signal DTS constructed by the gradient waveform construction circuit 20 gradually changes over time.

[0039] Finally, the motor drive circuit 30 sets one or more gradual drive signals DRS to be output to the motor MT based on a gradual waveform signal DTS received from the gradual waveform construction circuit 20, thereby driving the motor MT in a gradual manner while controlling the current flowing through the motor MT to be less than a current threshold. In particular, when the motor drive circuit 30 brakes the motor MT, it gradually increases or decreases the braking speed of the motor MT while controlling the reverse current (including the braking current) flowing through the motor MT to be less than a current threshold.

[0040] For example, when the duty cycle of the later-generated waveform among the multiple waveforms of a gradient waveform signal DTS output by the gradient waveform construction circuit 20 is larger, the motor drive circuit 30 brakes the motor MT faster. Conversely, when the duty cycle of the later-generated waveform among the multiple waveforms of a gradient waveform signal DTS output by the gradient waveform construction circuit 20 is smaller, the motor drive circuit 30 brakes the motor MT slower.

[0041] In other words, the motor driver of the present invention sets the duty cycle of multiple waveforms of a gradually changing waveform signal DTS to gradually change over time, thereby driving the motor MT in a gradually changing driving mode, gradually changing the speed of the motor MT, and in particular, the motor drive circuit 30 gradually changes (e.g., increases or decreases) the braking speed of the motor MT over time to prevent the motor MT from being damaged by overcurrent.

[0042] Please see Figure 2 This is a block diagram of a motor driver employing a gradual drive mechanism according to the second embodiment of the present invention. The similarities between the second embodiment and the first embodiment are not repeated herein.

[0043] The difference between the second embodiment of the present invention and the first embodiment is that the motor driver of the second embodiment of the present invention further includes an oscillation circuit 40.

[0044] The oscillation circuit 40 is connected to the gradual waveform construction circuit 20. The oscillation circuit 40 may include an oscillator. The oscillation circuit 40 can output an oscillating waveform signal WOS.

[0045] The gradient waveform construction circuit 20 uses multiple waveforms of an oscillation waveform signal WOS received from the oscillation circuit 40 as multiple oscillation waveforms, and uses multiple voltages on the multiple oscillation waveforms of the oscillation waveform signal WOS as multiple oscillation voltages.

[0046] On the other hand, the gradual drive setting circuit 10 outputs a gradual drive setting signal WBS based on multiple different gradual drive setting voltages set at multiple setting time points.

[0047] The gradient waveform construction circuit 20 compares the different gradient drive setting voltages set at multiple setting time points in a gradient drive setting signal WBS with the multiple oscillation voltages on multiple oscillation waveforms of an oscillation waveform signal WOS, so as to set the duty cycle of multiple waveforms of a gradient waveform signal DTS.

[0048] For example, the multiple oscillation waveforms of the oscillation waveform signal WOS include multiple triangular wave waveforms, multiple sawtooth wave waveforms, or combinations thereof. This is only an example and is not intended to limit the invention.

[0049] The motor drive circuit 30 sets one or more gradual drive signals based on the duty cycles of multiple waveforms of a gradual waveform signal received from the gradual waveform construction circuit 20, and outputs these one or more gradual drive signals to the motor MT, thereby driving the motor MT in a gradual drive mode.

[0050] Please see Figure 3 This is a block diagram of a motor driver employing a gradual drive mechanism according to the third embodiment of the present invention. The third embodiment of the present invention is similar to the first and second embodiments, and will not be described again herein.

[0051] The difference between the third embodiment and the second embodiment of the present invention is that the motor driver of the third embodiment further includes a speed detection circuit 50. The speed detection circuit 50 is connected to the gradual waveform construction circuit 20.

[0052] The gradual drive setting circuit 10, the gradual waveform construction circuit 20, the motor drive circuit 30, the oscillation circuit 40, and the speed detection circuit 50 described herein may each include one or more circuit components, but the present invention is not limited to the type and configuration of the circuit components.

[0053] The speed detection circuit 50 detects a gradual drive signal DRS output by the motor drive circuit 30 to the motor MT, and further infers the speed of the motor MT based on the detected gradual drive signal DRS to output a motor speed detection signal RPMS.

[0054] Next, the gradual waveform construction circuit 20 modulates the duty cycle of a gradual waveform signal DTS output to the motor drive circuit 30 based on a motor speed detection signal RPMS received from the speed detection circuit 50.

[0055] When the speed detection circuit 50 detects that the speed of the motor MT is not less than a speed threshold (e.g., zero), the gradual waveform construction circuit 20 can continuously and gradually increase the duty cycle of a gradual waveform signal DTS to strengthen the braking force of the motor drive circuit 30 on the motor MT.

[0056] Conversely, when the speed detection circuit 50 detects that the speed of the motor MT is less than a speed threshold (e.g., zero), the motor drive circuit 30 can stop gradually increasing the speed and maintain the duty cycle of a gradually increasing waveform signal DTS output to the motor drive circuit 30 to reduce the braking force on the motor MT, or stop outputting a gradually increasing waveform signal DTS to the motor drive circuit 30 to stop braking. In this way, braking can be stopped or the braking force reduced when the motor MT reaches the target speed or when the difference between the target speed and the target speed is less than a speed difference threshold, avoiding blindly increasing the braking force and current indefinitely.

[0057] Please see Figure 4 This is a circuit diagram of the comparison circuit included in the gradual waveform construction circuit of the motor driver employing a gradual drive mechanism according to the fourth embodiment of the present invention.

[0058] like Figure 2 or Figure 3 The gradient waveform construction circuit 20 shown may include a comparator circuit, which may include, for example: Figure 4 The comparator CMP is shown.

[0059] like Figure 4 The first input terminal of the comparator CMP shown is, for example, the non-inverting input terminal connected as follows: Figure 2 or Figure 3 The gradient drive setting circuit 10 shown is used to adjust the gradient from the given value. Figure 2 or Figure 3 The gradient drive setting circuit 10 shown receives a gradient drive setting signal WBS.

[0060] like Figure 4 The second input terminal of the comparator CMP shown is, for example, the inverting input terminal connected as follows: Figure 2 or Figure 3 The oscillating circuit 40 shown is used to oscillate from, as Figure 2 or Figure 3 The oscillation circuit 40 shown receives an oscillation waveform signal WOS.

[0061] like Figure 4The comparator CMP shown compares a gradual drive setting voltage set at each set time point in a gradual drive setting signal WBS with an oscillation voltage in an oscillation waveform signal WOS to set the logic level of a gradual waveform signal DTS, and outputs this gradual waveform signal DTS to... Figure 2 or Figure 3 The motor drive circuit 30 shown is shown.

[0062] The motor drive circuit 30 sets a gradual drive signal based on a gradual waveform signal DTS received from the comparator CMP and outputs this gradual drive signal to the motor MT, thereby driving the motor MT in a gradual manner, for example, gradually braking the motor MT.

[0063] Please see Figure 5 This is a waveform diagram of the signal of the motor driver using a gradual drive mechanism according to the fifth embodiment of the present invention.

[0064] like Figure 2 and Figure 3 The oscillation waveform signal WOS output by the oscillation circuit 40 shown can be the same as that shown. Figure 5 The oscillating waveform signal WOS1 shown has multiple triangular wave waveforms.

[0065] like Figure 2 and Figure 3 The gradual drive setting circuit 10 shown outputs a gradual drive setting signal WBS based on multiple gradual drive setting voltages set at multiple setting time points, which can be the same as... Figure 5 The gradient drive setting signal WBS1 shown has a gradient drive setting image, such as, but not limited to, an arrow image, a line image, or a curve image.

[0066] Specifically, after setting multiple gradient drive setting voltages at multiple set time points, the gradient drive setting circuit 10 can connect each set gradient drive setting voltage at the multiple set time points with a set gradient drive setting voltage at the next set time point (on a graph) as a gradient drive setting image segment. This allows setting multiple voltages at other non-set time points. Multiple gradient drive setting image segments between multiple set time points are connected to each other to generate a gradient drive setting image. For example... Figure 5 The gradient-driven setting image shown is a linearly changing line, but the present invention is not limited thereto.

[0067] The gradual drive setting circuit 10 can set a slope of a gradual drive setting image based on a drive demand information (such as, but not limited to, a braking speed demand information, including a return air volume, a return air intensity value, a return air speed value or any combination thereof around the motor MT) and other demand information.

[0068] Alternatively, the gradual drive setting circuit 10 can set multiple slopes of multiple gradual drive setting image segments based on multiple drive demand information (such as, but not limited to, braking speed demand information, including multiple return air volume, multiple return air intensity values, multiple return air speed values ​​or any combination thereof) in multiple time intervals.

[0069] The faster the braking speed indicated by the braking speed demand information, the greater the slope of the gradual drive setting image that the gradual drive setting circuit 10 can set. Conversely, the slower the braking speed indicated by the braking speed demand information, the smaller the slope of the gradual drive setting image that the gradual drive setting circuit 10 can set.

[0070] The gradient drive setting circuit 10 outputs a gradient drive setting signal WBS1 based on a gradient drive setting image.

[0071] The gradient waveform construction circuit 20 can, for example, Figure 5 The multiple gradual drive setting voltages set at multiple setting time points in the gradual drive setting signal WBS1 shown are respectively related to, as... Figure 5 The multiple oscillation voltages on multiple oscillation waveforms of the oscillation waveform signal WOS1 shown are compared to set, as follows: Figure 2 and Figure 3 The duty cycles of multiple waveforms in a gradually changing waveform signal DTS are shown.

[0072] Alternatively or alternatively, the gradient waveform construction circuit 20 can, for example, Figure 5 The voltages at multiple non-set time points on a gradual drive setting image of a gradual drive setting signal WBS1 are compared with multiple oscillation voltages on multiple oscillation waveforms of an oscillation waveform signal WOS1 to set the voltages as shown. Figure 2 and Figure 3 The duty cycles of multiple waveforms in a gradually changing waveform signal DTS are shown.

[0073] like Figure 2 and Figure 3 As shown, the motor drive circuit 30 can output a gradual drive signal DRS to the motor MT based on a gradual waveform signal DTS received from the gradual waveform construction circuit 20, thereby driving the motor MT in a gradual manner, for example, gradually changing the braking speed of the motor MT during braking.

[0074] For example, when the return air in the environment around the motor MT is low, the motor drive circuit 30 controls the braking current IBKS flowing through the motor MT to be less than the first reverse current threshold, so as to prevent the braking current of the motor MT from overcurrent and causing damage to the motor MT.

[0075] Conversely, when the return air in the environment around the motor MT is large, the motor drive circuit 30 controls a braking current IBKS flowing through the motor MT to be greater than the first reverse current threshold but less than the second reverse current threshold, so that the motor MT can be completely stopped without overcurrent.

[0076] In other words, in the fifth embodiment of the present invention, by appropriately setting a slope of a gradient drive setting image, multiple slopes of multiple gradient drive setting image segments, or a combination thereof, by the gradient drive setting circuit 10, the motor drive circuit 30 can drive the motor MT, for example, during the braking process of the motor MT, prevent the current flowing through the motor MT from becoming overcurrent and causing damage to the motor MT.

[0077] Please see Figure 6 This is a schematic diagram of the duty cycle versus time curve of the waveform of the gradually changing waveform signal of the motor driver employing a gradually changing drive mechanism according to the sixth embodiment of the present invention.

[0078] like Figures 1 to 3 The illustrated gradient waveform construction circuit 20 can modulate a gradient waveform signal DTS over time. This gradient waveform signal DTS can have the same characteristics as... Figure 6 The multiple waveforms shown indicate that the duty cycle of this gradually changing waveform signal DTS increases with time, causing the braking force of the motor MT to increase with time.

[0079] like Figure 6 The duty cycle time variation curve BKS1 shown is a curve of the duty cycle of a gradient waveform signal DTS changing with time. The duty cycle of this gradient waveform signal DTS increases with time, linearly increasing from the duty cycle "12.5%" corresponding to code 9D32 to the duty cycle "100%" corresponding to code 9D255. This is only an example and is not intended to limit the invention.

[0080] like Figure 3 The speed detection circuit 50 shown can be used in, for example Figure 6 The gradually changing waveform signal DTS shown represents a high level, a low level, or both time points. It detects a gradually changing drive signal DRS output by the motor drive circuit 30 to the motor MT.

[0081] Please see Figure 7This is a schematic diagram of multiple curves of the duty cycle versus time of the waveform of the gradually changing waveform signal of the motor driver employing a gradually changing drive mechanism according to the seventh embodiment of the present invention.

[0082] like Figures 1 to 3 The gradient waveform construction circuit 20 shown can modulate the slope of a curve showing the duty cycle of a gradient waveform signal DTS changing over time, for example, but not limited to, such as... Figure 7 The figure shows any one of the multiple duty cycle time variation curves BKS1, BKS2, and BKS3. These multiple duty cycle time variation curves BKS1, BKS2, and BKS3 have different slopes.

[0083] In other words, the gradient waveform construction circuit 20 can set and modulate the slope of a curve in which the duty cycle of a gradient waveform signal DTS changes over time, and the slope of this curve is a variable value.

[0084] The motor drive circuit 30 may include multiple upper bridge switches and multiple lower bridge switches. Each upper bridge switch has a first terminal, a second terminal, and a control terminal. Each lower bridge switch has a first terminal, a second terminal, and a control terminal. The first terminal of each upper bridge switch is coupled to a common voltage, and the second terminals of the multiple upper bridge switches are respectively connected to the first terminals of the multiple lower bridge switches, and respectively connected to multiple terminals of the motor MT.

[0085] To brake the motor MT faster, the gradient waveform construction circuit 20 outputs a gradient waveform signal DTS with a large slope to the motor drive circuit 30, so that the duty cycle of the conduction time signal of each or any upper bridge switch included in the motor drive circuit 30 is large, thereby making the braking current of the motor MT larger.

[0086] Unlike traditional drivers that fully open the lower bridge switch and fully close the upper bridge switch to brake the motor, the motor driver of this invention outputs a gradually changing waveform signal DTS with a duty cycle that varies over time. This gradually switches the upper and lower bridge switches from fully open to fully closed or from fully closed to fully open, providing a gradually increasing braking force to the motor MT, thus enabling more effective braking of the motor MT.

[0087] Please see Figure 8 This is a schematic diagram of the motor speed versus time curve detected by the motor driver using a gradual drive mechanism according to the eighth embodiment of the present invention.

[0088] like Figure 3As shown, the speed detection circuit 50 detects a gradual drive signal DRS output from the motor drive circuit 30 to the motor MT, and further infers the speed of the motor MT based on the detected gradual drive signal DRS to output a motor speed detection signal RPMS. The motor drive circuit 30 modulates the gradual drive signal DRS output to the motor MT based on the motor speed detection signal RPMS.

[0089] like Figure 3 The motor speed detection signal RPMS shown can be the same as... Figure 8 The motor speed detection signal RPMS1 shown indicates that the speed of motor MT decreases as time increases, at which point the motor driver of this invention brakes motor MT. During the braking process of motor MT, as... Figure 8 The braking current IBKS shown flows through the motor MT.

[0090] As time increases, the duty cycle of the duty cycle curve BKS1 gradually increases, causing the braking current IBKS flowing through the motor MT to increase the braking force of the motor MT. Figure 8 As shown, the downward slope of a curve for a motor speed detection signal RPMS1 increases with time.

[0091] Please see Figure 9 This is a waveform diagram of the signal of the motor driver using a gradual drive mechanism according to the ninth embodiment of the present invention.

[0092] like Figure 3 The speed detection circuit 50 shown can be used in, for example Figure 9 The detection time indication signal DES1 shown is a gradually changing drive signal DRS output by the motor drive circuit 30 to the motor MT during a high-level time period. Based on the detected gradually changing drive signal DRS, the rotational speed of the motor MT is inferred and output as shown. Figure 3 A motor speed detection signal RPMS, this motor speed detection signal RPMS can be the same as such Figure 9 The image shows a motor speed detection signal RPS1.

[0093] like Figure 3 The gradient waveform signal DTS output by the gradient waveform construction circuit 20 shown can be the same as... Figure 9 The waveform signal DTS1 shown is a gradually changing waveform.

[0094] The motor drive circuit 30 can set or modulate a gradual drive signal DRS based on a motor speed detection signal RPS1 and a gradual waveform signal DTS1, so that a current signal IMS1 of the motor MT is set as follows: Figure 9 As shown.

[0095] Please see Figure 10 This is a waveform diagram of the signal of the motor driver using a gradual drive mechanism according to the tenth embodiment of the present invention.

[0096] like Figure 3 The speed detection circuit 50 shown can be used in, for example Figure 10 The detection time indication signal DES2 shown is a gradually changing drive signal DRS output by the motor drive circuit 30 to the motor MT during a high-level time period. Based on the detected gradually changing drive signal DRS, the rotational speed of the motor MT is inferred and output as shown. Figure 3 A motor speed detection signal RPMS, this motor speed detection signal RPMS can be the same as such Figure 10 The image shows a motor speed detection signal RPS2.

[0097] like Figure 3 The gradient waveform signal DTS output by the gradient waveform construction circuit 20 shown can be the same as... Figure 10 The waveform signal DTS2 shown is a gradually changing waveform.

[0098] The motor drive circuit 30 can set or modulate a gradual drive signal DRS based on a motor speed detection signal RPS1 and a gradual waveform signal DTS2, so that a current signal IMS2 of the motor MT is set as follows: Figure 10 As shown.

[0099] The gradual drive setting circuit 10 sets a gradual drive setting signal WBS with different slopes, which will cause the speed detection circuit 50 to output a different gradual waveform signal DTS based on the gradual drive setting signal WBS. For example... Figure 10 The duty cycle of the gradually changing waveform signal DTS2 shown is different from that of... Figure 9 The operating cycle of the gradually changing waveform signal DTS1 is shown. Therefore, the motor drive circuit 30 operates according to... Figure 10 The current signal IMS2 of the motor MT driven by the gradually changing waveform signal DTS2 shown is different from that shown in the figure. Figure 9 The current signal IMS1 of the motor MT driven by the gradually changing waveform signal DTS1 is shown.

[0100] In other words, the motor driver of the present invention can appropriately control and change the current flowing through the motor MT by appropriately modulating the slope of a gradual drive setting signal WBS, including changing the current of the motor (including reverse current, such as the braking current described herein) in terms of current quantity and rate of change per unit time, so as to prevent the motor MT from being damaged due to overcurrent.

[0101] In summary, this invention provides a motor driver employing a gradual driving mechanism. The motor driver of this invention uses a gradual driving mechanism to provide progressive braking force to the motor, appropriately controlling the current flowing through the motor, especially when braking the motor, to prevent damage to the motor due to overcurrent. For example, when the return air around the motor is strong, the motor driver of this invention increases the braking current flowing through the motor to achieve complete braking; conversely, when the return air around the motor is weak, the motor driver of this invention reduces the braking current flowing through the motor to achieve braking while preventing damage to the motor due to overcurrent.

[0102] The above-disclosed content is only a preferred and feasible embodiment of the present invention and is not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A motor driver employing a gradual drive mechanism, characterized in that, The motor driver employing a gradual drive mechanism includes: A gradual drive setting circuit is configured to output a gradual drive setting signal that varies with time, the gradual drive setting signal having multiple different gradual drive setting voltages set at multiple set time points respectively. A gradient waveform construction circuit is connected to the gradient drive setting circuit. The gradient waveform construction circuit is configured to set multiple waveforms of a gradient waveform signal based on multiple gradient drive setting voltages at multiple setting time points in the gradient drive setting signal. The multiple duty cycles of the multiple waveforms of the gradient waveform signal are different from each other. as well as A motor drive circuit is connected to the gradient waveform construction circuit and the motor. The motor drive circuit is configured to output a gradient drive signal to the motor based on the gradient waveform signal.

2. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The motor drive circuit brakes the motor and gradually changes the braking speed of the motor over time.

3. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The gradient waveform construction circuit includes a comparison circuit configured to compare the gradient drive setting voltage set at each of the set time points with an oscillation voltage to output the gradient waveform signal.

4. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The motor driver employing a gradual drive mechanism further includes: An oscillating circuit, connected to the gradient waveform construction circuit, is configured to output an oscillating waveform signal having multiple oscillating waveforms; The gradual waveform construction circuit uses multiple voltages on multiple oscillating waveforms as multiple oscillating voltages, and compares the gradual drive setting voltages set at multiple set time points with the multiple oscillating voltages to set multiple duty cycles of the multiple waveforms of the gradual waveform signal.

5. The motor driver employing a gradual drive mechanism according to claim 4, characterized in that, The oscillating waveform signal includes multiple triangular wave waveforms, multiple sawtooth wave waveforms, or combinations thereof.

6. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The gradient drive setting circuit connects the gradient drive setting voltage of each of the plurality of setting time points with the gradient drive setting voltage of the next setting time point in a gradient drive setting image segment. The plurality of gradient drive setting image segments between the plurality of setting time points are connected to each other to generate a gradient drive setting image. The gradient drive setting circuit outputs the gradient drive setting signal according to the gradient drive setting image.

7. The motor driver employing a gradual drive mechanism according to claim 6, characterized in that, The gradient waveform construction circuit compares the gradient drive setting voltage set at each of the set time points on the gradient drive setting image with an oscillation voltage to set multiple duty cycles of multiple waveforms of the gradient waveform signal.

8. The motor driver employing a gradual drive mechanism according to claim 7, characterized in that, The gradient waveform construction circuit compares multiple voltages at multiple non-set time points on the gradient drive setting image with multiple oscillation voltages to set multiple duty cycles of multiple waveforms of the gradient waveform signal.

9. The motor driver employing a gradual drive mechanism according to claim 6, characterized in that, The gradient drive setting circuit sets the slope of the gradient drive setting image based on a drive requirement information.

10. The motor driver employing a gradual drive mechanism according to claim 6, characterized in that, The gradient drive setting circuit sets multiple slopes for multiple gradient drive setting image segments based on multiple drive demand information within multiple time intervals.

11. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The gradient drive setting circuit constructs a ladder-shaped waveform image in the gradient drive setting signal. The ladder-shaped waveform image has multiple ladder segments, the height of each ladder segment is the gradient drive setting voltage, and the multiple widths of the multiple ladder segments are multiple time lengths.

12. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The motor driver employing a gradual drive mechanism further includes: A speed detection circuit is connected to the motor drive circuit and configured to detect the gradual drive signal, infer the speed of the motor based on the detected gradual drive signal, and output a motor speed detection signal.

13. The motor driver employing a gradual drive mechanism according to claim 12, characterized in that, The motor drive circuit modulates and outputs the gradual drive signal to the motor based on the motor speed detection signal.

14. The motor driver employing a gradual drive mechanism according to claim 12, characterized in that, When the speed of the motor is not less than a certain speed threshold, the motor drive circuit will brake the motor.

15. The motor driver employing a gradual drive mechanism according to claim 14, characterized in that, When the speed of the motor is less than the speed threshold, the motor drive circuit stops braking the motor.

16. The motor driver employing a gradual drive mechanism according to claim 14, characterized in that, The critical value for the rotational speed is zero.

17. The motor driver employing a gradual drive mechanism according to claim 1, characterized in that, The motor is either a three-phase motor or a single-phase motor.

Images