TWI533585B - Motor drive - Google Patents

Description

Motor drive

The present invention relates to a driving device, and more particularly to a motor driving device.

In a general motor drive device, since the motor uses a large current or a high voltage operation, the electrical connection switch and the entire current path need to use components that can withstand higher power, and thus, the relative volume or area of the product is relatively high. Big.

Accordingly, it is an object of the present invention to provide a motor drive that reduces the volume of a product.

Therefore, the motor driving device of the present invention is suitable for driving a motor of a power tool, the motor driving device comprising a driving circuit, a first switch, a control circuit, and a power circuit.

The drive circuit is adapted to electrically connect the motor, receive an external supply of power and be controlled to drive the motor forward and reverse.

The first switch includes a first end for receiving the externally supplied power, and a second end, and is controlled to be switched between conducting and non-conducting.

The control circuit is electrically connected to the driving circuit and the first switch The second end controls the driving circuit according to the conduction state of the first switch. When the first switch is turned on, the driving circuit is controlled to drive the motor to rotate forward. When the first switch is not conducting, the driving circuit is controlled to drive the driving circuit. The motor is reversed.

The power circuit is electrically connected to the first end and the second end of the first switch and the control circuit, receives the externally supplied power, and selectively outputs an internal power associated with the externally supplied power according to the conductive state of the first switch Power is supplied to the control circuit to output the internal power during the first switch being turned on and immediately after a predetermined period of time.

Thereby, after the first switch is not turned on, the motor is stopped after being reversed for the predetermined time.

The effect of the present invention is that the power circuit can be separated from the motor by providing the power circuit at the front end of the control circuit and using the control circuit to control the drive circuit to rotate the motor forward and reverse. Outside the current path, the first switch and the power supply circuit can be implemented using low power components, thereby reducing the volume of the product.

2‧‧‧Drive circuit

21‧‧‧Switching elements

3‧‧‧First switch

31‧‧‧ first end

32‧‧‧second end

4‧‧‧Control circuit

41‧‧‧Filter module

42‧‧‧Microprocessor

5‧‧‧Power circuit

51‧‧‧Second switch

511‧‧‧ first end

512‧‧‧ second end

52‧‧‧Control unit

521‧‧‧RC delay module

522‧‧‧Time Module

53‧‧‧Stabilizer

6‧‧‧Detection unit

61‧‧‧ Current detection circuit

611‧‧‧resistance

62‧‧‧ Temperature detection circuit

621‧‧‧ Temperature detecting element

7‧‧‧Voltage input circuit

71‧‧‧Variable resistor

9‧‧‧Motor

Vs‧‧‧ internal power

Vcc‧‧‧ externally supplied electricity

Other features and advantages of the present invention will be apparent from the embodiments of the present invention. FIG. 1 is a schematic diagram of a first preferred embodiment of the motor driving device of the present invention; FIG. 2 is the first FIG. 3 is a schematic circuit diagram of a second preferred embodiment of a motor driving device of the present invention; and FIG. 4 is a circuit diagram of a third preferred embodiment of the motor driving device of the present invention; schematic diagram.

Referring to FIG. 1 and FIG. 2, a first preferred embodiment of the motor driving device of the present invention is suitable for driving a motor 9 of a power tool (not shown). The motor driving device includes a driving circuit 2, including a first The first switch 3 of the one end 31 and the second end 32, a control circuit 4, a power supply circuit 5, and a detecting unit 6.

The driving circuit 2 is adapted to electrically connect the motor 9, receives an externally supplied electric power Vcc and is controlled to drive the motor 9 to rotate forward and reverse. In the present embodiment, the driving circuit 2 is provided with four switching elements 21. In the H-bridge circuit, two and two of the switching elements 21 are respectively connected in series between the first end 31 of the first switch 3 and the ground, and the switching elements 21 use a relay (RELAY), a transistor Equal power components are implemented, but are not limited thereto.

Since the operation mode of the driving circuit 2 is familiar to the industry, it will not be described here.

The first switch 3 is controlled to be switched between conduction and non-conduction, and the first end 31 is configured to receive the externally supplied power Vcc.

The control circuit 4 is electrically connected to the driving circuit 2, the second end 32 of the first switch 3, and the driving circuit 2 is controlled according to the conduction state of the first switch 3. When the first switch 3 is turned on, the driving circuit is controlled. 2, the motor 9 is driven to rotate forward, and when the first switch 3 is not turned on, the drive circuit 2 is controlled to drive the motor 9 to reverse.

The power circuit 5 is electrically connected to the first end 31 of the first switch 3 And the second terminal 32 and the control circuit 4 receive the external power supply Vcc, and selectively output an internal power Vs associated with the external power supply Vcc according to the conduction state of the first switch 3 to supply power to the control circuit 4. The internal power Vs is output during the first switch 3 being turned on and immediately after a predetermined period of time.

The power circuit 5 includes a second switch 51 and a control unit 52.

The second switch 51 includes a first end 511 electrically connected to the first end 31 of the first switch 3 and receiving the external supply power Vcc, and a second end 512 electrically connected to the control circuit 4, controlled to be turned on. And switch between non-conducting.

The control unit 52 is electrically connected to the second end 32 of the first switch 3 and the second switch 51, and controls the second switch 51 to be turned on during the conduction of the first switch 3 and the subsequent predetermined period of time. The second end 512 of the second switch 51 outputs the external power Vcc as the internal power Vs, and the control unit 52 includes an RC delay module 521 for determining the predetermined length of time.

The detecting unit 6 includes a current detecting circuit 61 electrically connected to the control circuit 4, and the current detecting circuit 61 is electrically connected to one of the switching elements 21 of the driving circuit 2, and outputs a voltage associated with the switching element 21 A poor current detection signal is sent to the control circuit 4.

For example, when the applied power tool is a device for squeezing a viscous material, when the user wants to squeeze out the viscous material, the first switch 3 (generally a trigger on the power tool) can be operated to make the first Switch 3 is turned on, The control unit 52 controls the second switch 51 to be turned on, and outputs the internal power Vs to the control circuit 4 at the second end 512 of the second switch 51. The control circuit 4 controls the drive circuit 2 to make the motor 9 The forward rotation causes the viscous material to be extruded.

After the user operates the first switch 3 to make the first switch 3 non-conducting, by setting the RC delay module 521, the control unit 52 delays the predetermined period of time to control the second switch 51 to be non-conductive to stop. The internal power Vs is output, and the control circuit 4 controls the drive circuit 2 to invert the motor 9 for a predetermined period of time, and stops operating after the power circuit 5 stops outputting the internal power Vs to stop the motor 9 from running. In this way, after the first switch 3 is not turned on, the motor 9 can be stopped after the predetermined time is reversed, so that the viscous material is slightly recovered without causing inconvenience in use.

Through the above description, the advantages of this embodiment can be summarized as follows:

1. The power supply circuit 5 can be separated from the front end of the control circuit 4 and used in conjunction with the control circuit 4 to control the drive circuit 2 to rotate the motor 9 forward and reverse. The current path of the motor 9 is outside, so the first switch 3, the second switch 51 and the control unit 52 can be implemented using low power components, since the volume of the low power component is smaller than the volume of the high power component, Conventional techniques can reduce the volume or area of the product.

2. By setting the power circuit 5 to the front end of the control circuit 4, the first switch 3 can be stopped after the predetermined period of time after the non-conduction is turned on. The internal power Vs output is stopped, so that the power loss during the standby of the control circuit 4 can be completely terminated, and the energy saving effect can be achieved.

3. By using the conduction and non-conduction states of the first switch 3 as the basis for determining the control circuit 4, the effect of controlling the drive circuit 2 to rotate the motor 9 forward or reverse can be achieved using a simple architecture.

4. By setting the current detecting circuit 61 and feeding back the current detecting signal to the control circuit 4, the control circuit 4 can determine the current current state of the motor 9 to provide power-off protection in case of overcurrent. .

Referring to FIG. 3, a second preferred embodiment of the motor driving device of the present invention is similar to the first preferred embodiment, the second preferred embodiment and the first preferred embodiment. The difference between the embodiments is that two of the switching elements 21 are connected in series between the first end 31 of the first switch 3 and the ground, and the other two are connected in series to the second end 32 of the first switch 3 and Between the ground terminals.

The control circuit 4 includes a filter module 41 and a microprocessor 42.

The filter module 41 is electrically connected to the second end 32 of the first switch 3, and filters the voltage of the second end 32 of the first switch 3 to generate a filtered voltage.

The microprocessor 42 is electrically connected to the filter module 41 and the driving circuit 2, and controls the driving circuit 2 according to the filtering voltage outputted by the filtering module 41. When the first switch 3 is turned on, the driving circuit 2 is controlled. The motor 9 is driven to rotate forward, and when the first switch 3 is not turned on, the drive circuit 2 is controlled to drive the motor 9 to reverse.

The power supply circuit 5 further includes a voltage stabilizing unit 53. The control unit 52 controls the second switch 51 to be turned on during the first period of the first switch 3 and the predetermined period of time, for the second switch 51. The two terminals 512 output the externally supplied power Vcc.

The voltage stabilizing unit 53 is electrically connected between the second end 512 of the second switch 51 and the control circuit 4, receives the external power supply Vcc outputted by the second end 512 of the second switch 51, and is regulated to generate The internal power Vs, wherein the voltage stabilizing unit 53 is one of a voltage stabilizing IC circuit, a transistor voltage stabilizing circuit, and a diode voltage stabilizing circuit.

The detecting unit 6 further includes a temperature detecting circuit 62 electrically connected to the control circuit 4.

The current detecting circuit 61 includes a resistor 611 connected in series with the driving circuit 2, and outputs a current detecting signal associated with a voltage difference across the resistor 611 to the control circuit 4.

The temperature detecting circuit 62 is disposed corresponding to the motor 9, and includes a temperature detecting component 621 for detecting the temperature of the motor 9, and outputs a corresponding temperature detecting signal to the control circuit 4, wherein the temperature detecting is performed. The component 621 is one of a thermistor, a temperature switch, a platinum induction resistor, and a temperature sensing IC.

The embodiment further includes a voltage input circuit 7 electrically connected to the control circuit 4. The voltage input circuit 7 is controlled to output a voltage control signal to the control circuit 4, and includes a variable resistor 71. The variable resistor 71 Controlled to output different potential signals as the voltage control signal, wherein the potential signal of the voltage input circuit 7 is supplied to the control circuit 4 through the drive The dynamic circuit 2 controls an operation mode of the motor 9, and the potential signal is associated with at least one of a motor rotation speed, a motor temperature setting value, a motor maximum current setting value, and a motor running time setting value.

Thus, the second preferred embodiment has the following effects in addition to the same purpose and effect as the first preferred embodiment described above:

1. In this embodiment, the second switch 51 and the control unit 52 can be implemented using low power components, which can reduce the volume or area of the product compared to the prior art.

2. By adding the temperature detecting circuit 62 and feeding back the temperature detecting signal to the control circuit 4, the control circuit 4 can determine the current temperature state of the motor 9 to be overheated when the motor 9 is over temperature. Provide power failure protection.

3. By providing the voltage input circuit 7, the user can adjust the output of the voltage control signal to control the operation mode of the motor 9 via the control circuit 4 and the drive circuit 2, thereby increasing the convenience of use. Sex.

Referring to FIG. 4, a third preferred embodiment of the motor driving device of the present invention is similar to the first preferred embodiment, the third preferred embodiment and the first preferred embodiment. The difference between the embodiments is that the control unit 52 includes a timing module 522 for determining the predetermined length of time, and the timing module 522 is a timer chip.

Thus, the third preferred embodiment can achieve the same purpose and effect as the first preferred embodiment described above.

In summary, the present invention can not only reduce the volume of the product or The area and the power consumption during standby can be saved, and the power-off protection can be provided in the case of over-temperature or over-current, and the convenience in use can be increased, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

2‧‧‧Drive circuit

21‧‧‧Switching elements

3‧‧‧First switch

31‧‧‧ first end

32‧‧‧second end

4‧‧‧Control circuit

5‧‧‧Power circuit

51‧‧‧Second switch

511‧‧‧ first end

512‧‧‧ second end

52‧‧‧Control unit

521‧‧‧RC delay module

6‧‧‧Detection unit

61‧‧‧ Current detection circuit

9‧‧‧Motor

Vs‧‧‧ internal power

Vcc‧‧‧ externally supplied electricity

Claims (9)

A motor driving device is adapted to drive a motor of a power tool, the motor driving device comprising: a driving circuit adapted to electrically connect the motor, receive an externally supplied power and be controlled to drive the motor to rotate forward and reverse; a first switch includes a first end for receiving the externally supplied power, and a second end, and is controlled to be switched between conducting and non-conducting; a control circuit electrically connecting the driving circuit, the first switch The two ends control the driving circuit according to the conduction state of the first switch, and when the first switch is turned on, controlling the driving circuit to drive the motor to rotate forward, and when the first switch is not conducting, controlling the driving circuit to drive the motor And a power circuit electrically connecting the first end and the second end of the first switch and the control circuit to receive the externally supplied power, and according to the conductive state of the first switch, the selective output is associated with the external Supplying internal power of the power to supply the control circuit, outputting the internal power during the first switch being turned on and immediately after a predetermined period of time, and the power source The circuit includes a second switch including a first end electrically connected to the first end of the first switch and receiving the externally supplied power, and a second end electrically connected to the control circuit, controlled between the conducting and the non-conducting Switching, and a control unit electrically connecting the second end of the first switch and the second switch, and controlling the second switch to be turned on during the first switch being turned on and the next predetermined period of time Second end of the second switch The externally supplied electric power is output as the internal electric power; thereby, after the first switch is not turned on, the motor is reversed for the predetermined time and then stopped. The motor driving device of claim 1, wherein the power supply circuit further comprises: a voltage stabilizing unit electrically connected between the second end of the second switch and the control circuit, and receiving the second end of the second switch The externally supplied power is supplied and regulated to generate the internal power. The motor driving device of claim 1, wherein the control circuit comprises: a filter module electrically connected to the second end of the first switch, and filtering the voltage of the second end of the first switch to generate a filter voltage, and a microprocessor electrically connecting the filter module and the drive circuit, controlling the drive circuit according to the filter voltage output by the filter module, and controlling the drive circuit when the first switch is turned on The motor rotates forward, and when the first switch is not conducting, the drive circuit is controlled to drive the motor to reverse. The motor driving device of claim 1, further comprising a current detecting circuit electrically connected to the control circuit, the current detecting circuit comprising a resistor connected in series with the driving circuit, and outputting a voltage difference associated with the voltage across the resistor A current detection signal is sent to the control circuit. The motor driving device of claim 1, wherein the driving circuit is an H-bridge circuit having four switching elements. The motor driving device of claim 5, further comprising a current detecting circuit electrically connected to the control circuit, the current detecting circuit electrically connecting one of the switching elements of the driving circuit, and outputting the two ends of the switching element A current detection signal of the voltage difference is applied to the control circuit. The motor driving device of claim 5, wherein two or two of the switching elements are respectively connected in series between the first end of the first switch and the ground. The motor driving device of claim 5, wherein two of the switching elements are connected in series between the first end of the first switch and the ground, and the other two are connected in series with the second of the first switch Between the end and the ground. The motor driving device of claim 1, wherein the power circuit comprises one of an RC delay module for determining the predetermined length of time and a timing module for determining the predetermined length of time.