KR102271805B1 - Apparatus for driving step motor - Google Patents

Abstract

The present invention relates to a stepper motor driving device capable of reducing the number of ports required for controlling the stepper motor. A step motor driving device according to an embodiment of the present invention is a step motor comprising a stator in which a coil corresponding to each of four phases is wound, and a rotor disposed in the stator and rotated by a magnetic field generated in the coil ( step motor), a driving circuit that operates according to each driving pulse provided through four input terminals to supply current to each coil wound on the stator, and first and second control pulses having different high sections through two output terminals and a controller that outputs each of the , and controls a relay selectively connecting the two output terminals and any two input terminals of the driving circuit to provide each of the driving pulses to the driving circuit.

Description

Step motor driving device {APPARATUS FOR DRIVING STEP MOTOR}

The present invention relates to a stepper motor driving device capable of reducing the number of ports required for controlling the stepper motor.

A stepper motor is a motor in which a rotor rotates step by step as much as a specific angle, accurate position control, and relatively low cost compared to other motors, and thus is widely used in various fields.

A stepper motor is composed of a stator with coils wound and a rotor rotating in the stator. Depending on the number of coils wound on the stator (number of poles), single-phase, one-phase, two-phase, three-phase motors are used. Phase, Phase 4, … divided into, etc.

For example, the most widely used four-phase stepper motor includes a stator in which a coil corresponding to each of four phases is wound, and a rotor that rotates according to a magnetic field generated in the coil in the stator.

Hereinafter, a step motor driving apparatus for driving the above-described step motor will be described in detail with reference to FIGS. 1 and 2 .

Referring to FIG. 1 , the conventional step motor driving apparatus 10 includes a micro controller unit (MCU) 11 , a driving circuit 12 , a step motor 13 , and a power supply 14 .

The driving circuit 12 drives the step motor 13 by selectively connecting the power source 14 and each of the four coils provided in the step motor 13 according to the control signals S1 to S4 of the MCU 11 . do.

More specifically, the driving circuit 12 connects the power source 14 and the first coil of the stepper motor 13 according to the first control signal S1 provided from the MCU 11 to supply the current ia to the first coil. ) to flow, and according to the second control signal S2 provided from the MCU 11, the power source 14 and the second coil of the stepper motor 13 are connected to allow the current ib to flow in the second coil. control so as to

Similarly, the driving circuit 12 connects the power source 14 and the third coil of the step motor 13 according to the third control signal S3 provided from the MCU 11 so that a current ic flows through the third coil. and control the current (id) to flow through the fourth coil by connecting the power source 14 and the fourth coil of the stepper motor 13 according to the fourth control signal S4 provided from the MCU 11 .

Referring to FIG. 2 , the MCU 11 outputs first to fourth control signals S1 to S4 each having a sequentially continuous pulse shape, and the driving circuit 12 includes the first to fourth control signals ( S1 to S4 ). Currents ia, ib, ic, and id are supplied to each coil of the stepper motor 13 by sequentially performing the above-described operations according to S1 to S4).

The first to fourth coils form a magnetic field in a clockwise or counterclockwise direction by the sequentially supplied currents ia, ib, ic, and id, and the rotor rotates clockwise or counterclockwise according to the magnetic field.

According to the operation of the step motor driving device 10 described above, the MCU 11 having a limited number of ports must drive the step motor 13 using a total of four ports (or pins).

Meanwhile, the MCU 11 performs various processing and control operations in addition to driving the step motor 13 described above. When four ports are used for driving the step motor 13 , additional operations other than driving the step motor 13 are used. A problem of insufficient ports for operation may occur, and in order to prevent this, when the MCU 11 having an increased number of ports is applied, there is a problem in that the production cost of the stepper motor driving device 10 increases.

An object of the present invention is to provide a stepper motor driving apparatus capable of reducing the number of ports required for controlling the stepper motor through relay control.

Another object of the present invention is to provide a stepper motor driving device capable of driving the stepper motor in a 1-2 phase excitation method through two control signals.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

The step motor driving apparatus of the present invention includes a controller that outputs a control pulse through two ports and selectively provides a control pulse to a driving circuit by controlling a relay through one port, so that the number of ports required for controlling the step motor can reduce

In addition, the step motor driving apparatus of the present invention includes a capacitor for maintaining the voltage of the control pulse at the input terminal of the driving circuit to which the control pulse having a relatively small duty ratio is provided, thereby excitation of the step motor through two ports in 1-2 phases. method can be driven.

The present invention can save one or more ports compared to the prior art by reducing the number of ports required to control the stepper motor through relay control, thereby reducing cost and additional functions in the PCB (Printed Circuit Board) design of the stepper motor driving device It has the advantage that it can be mounted.

In addition, the present invention has the advantage of efficiently driving the stepper motor while saving ports by driving the stepper motor in a 1-2 phase excitation method through two control signals.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 is a view for explaining a conventional step motor driving method.
FIG. 2 is a diagram illustrating a control pulse output from the MCU shown in FIG. 1; FIG.
3 is a view showing a stepper motor driving device according to an embodiment of the present invention.
4 is a view showing an example of the step motor shown in FIG.
5 is a view showing an example of the driving circuit shown in FIG.
6 and 7 are views showing examples of driving pulses provided to a driving circuit.
8 is a view showing an example of a switching pulse provided to the relay shown in FIG.
9A and 9B are diagrams for explaining the operation of the relay according to the switching pulse shown in FIG.
10 is a waveform diagram illustrating two control pulses and a switching pulse that do not overlap a high section, and a driving pulse generated based thereon;
11 is a waveform diagram illustrating two control pulses in which a high section partially overlaps;
12 is a diagram illustrating a state in which a capacitor is provided at an input terminal of a driving circuit to which any one control pulse is provided.
13 is a waveform diagram illustrating two control pulses and a switching pulse in which a high section partially overlaps, and a driving pulse generated based thereon;

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same or similar components.

Hereinafter, when it is described that a component is “connected”, “coupled” or “connected” to another component, the components may be directly connected or connected to each other, but other components may be interposed between each component. It should be understood that each component may be “interposed” or “connected,” “coupled,” or “connected” through another component.

The present invention relates to a stepper motor driving device capable of reducing the number of ports required for controlling the stepper motor. Hereinafter, a step motor driving apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 to 13 .

3 is a view showing a stepper motor driving apparatus according to an embodiment of the present invention. FIG. 4 is a view showing an example of the step motor shown in FIG. 3 , and FIG. 5 is a view showing an example of the driving circuit shown in FIG. 3 .

6 and 7 are diagrams illustrating examples of driving pulses provided to a driving circuit. 8 is a diagram illustrating an example of a switching pulse provided to the relay illustrated in FIG. 3 , and FIGS. 9A and 9B are diagrams for explaining an operation of the relay according to the switching pulse illustrated in FIG. 8 .

10 is a waveform diagram illustrating two control pulses and a switching pulse that do not overlap a high section, and a driving pulse generated based thereon.

11 is a waveform diagram illustrating two control pulses in which a high section partially overlaps.

12 is a diagram illustrating a state in which a capacitor is provided at an input terminal of a driving circuit to which one control pulse is provided. Also, FIG. 13 is a waveform diagram illustrating two control pulses and a switching pulse in which a high section partially overlaps, and a driving pulse generated based thereon.

Referring to FIG. 3 , the step motor driving apparatus 100 according to an embodiment of the present invention may include a controller 110 , a driving circuit 120 , a step motor 130 , and a driving power source 140 . The step motor driving device 100 shown in FIG. 3 is according to an embodiment, and its components are not limited to the embodiment shown in FIG. 3 , and some components may be added, changed or deleted as necessary. can

The step motor 130 is a motor in which the rotor 132 rotates step by step by a specific angle, accurate position control is possible, and has the advantage of being relatively inexpensive compared to other motors, so it is widely used in various fields. .

The step motor 130 may include a stator 131 in which a coil is wound, and a rotor 132 rotating in the stator 131 . This stepper motor 130 is single-phase, 1-phase, 2-phase, 3-phase, 4-phase, ... depending on the number of coils wound on the stator 131 (the number of poles). and the like, and the rotation angle (hereinafter, step angle) of the rotor 132 in a single step may vary according to the number of coils (the number of poles).

The step motor 130 of the present invention to be described later is a four-phase step motor 130, a stator 131 in which coils corresponding to each of the four phases are wound, and a magnetic field generated in each coil disposed in the stator 131. It may include a rotor 132 that rotates by.

The stepper motor 130 may have various shapes depending on the winding method of the coil and the method of supplying current to the coil. However, hereinafter, for convenience of description, it is assumed that the step motor 130 of the present invention is a step motor 130 of a four-phase permanent magnet type (PM).

Referring to FIG. 4 , the stepper motor 130 may include a stator 131 having four teeth 131a to 131d. Coils corresponding to the two phases may be wound on the two teeth disposed opposite to each other. For example, coils (A-A', C-C') corresponding to phases A and C may be wound on two teeth disposed oppositely in the y-axis direction in FIG. 4 , and are disposed oppositely in the x-axis direction. Coils (B-B', D-D') corresponding to phase B and phase D may be wound on the two teeth.

At this time, the coil A-A' corresponding to the A phase and the coil C-C' corresponding to the C phase may be wound in opposite directions, and the coil corresponding to the B phase (B-B') and the coils D-D' corresponding to the phase D may also be wound in opposite directions.

When a current flows in the coil corresponding to each phase, a magnetic field may be generated in the teeth of the stator 131 in which the coil is wound. The magnetic rotor 132 is disposed in the stator 131 and can be rotated by a magnetic field generated from the teeth of the stator 131 .

In order to generate a magnetic field in the stator 131 , the driving circuit 120 may supply a current to a coil corresponding to each phase. More specifically, the driving circuit 120 may supply current to each coil wound around the stator 131 by operating according to each driving pulse D1 to D4 provided through four input terminals.

As shown in FIG. 3 , the driving circuit 120 may include four input terminals #1' to #4', and transmit driving pulses D1 to D4 for each coil to the four input terminals #1. It can be provided through '~#4'). The driving circuit 120 may operate according to each driving pulse D1 to D4 to supply current output from the driving power source 140 to each coil.

To this end, the driving circuit 120 may include a driving transistor that switches according to the driving pulses D1 to D4 and supplies the current supplied from the driving power 140 to each coil.

Referring to FIG. 5 , the driving circuit 120 is a unipolar circuit, and coils A-A', B-B', C-C' corresponding to phases A, B, C, and D, respectively. , D-D′), a diode limiting the direction of current flowing in the coil, and a driving transistor selectively connecting the driving power source 140 and the coil.

The driving transistor may include first to fourth driving transistors Tr1 to Tr4 corresponding to phases A, B, C, and D, respectively. In this case, the first to fourth driving transistors Tr1 to Tr4 may operate according to the driving pulses D1 to D4 for the A, B, C, and D phases, respectively.

More specifically, the driving pulses D1 to D4 provided to the driving circuit 120 are applied to the gate terminals of the driving transistors Tr1 to Tr4, and the driving transistor has a high section HR of the driving pulses D1 to D4. may connect the driving power source 140 and the coil.

The driving pulses D1 to D4 may have a high value exceeding the threshold voltage of the driving transistor or a low value less than the threshold voltage of the driving transistor. In this case, a section in which a high value is maintained in the driving pulses D1 to D4 may be defined as a high section HR.

In the high period HR, since a high value is applied to the gate terminal of the driving transistor, the driving transistor is turned on to connect the driving power 140 and the coil. On the other hand, since the low value is applied to the gate terminal of the driving transistor in a section other than the high section HR, the driving transistor is turned off to cut off the connection between the driving power source 140 and the coil.

Only when the driving power source 140 and the coil are connected, the current output from the driving power source 140 may flow through the coil. When a current flows in the coil, a magnetic field may be generated in the teeth of the stator 131 on which the coil is wound, and the rotor 132 may rotate in the stator 131 according to a location of the magnetic field.

In order to rotate the rotor 132 in a predetermined direction and torque, the driving circuit 120 operates according to each driving pulse D1 to D4 sequentially having the high section HR of the same interval to apply a current to each coil. can supply

Hereinafter, the driving pulse corresponding to the A phase is the first driving pulse D1, the driving pulse corresponding to the B phase is the second driving pulse D2, and the driving pulse corresponding to the C phase is the third driving pulse (D1). With reference to D3), a driving pulse corresponding to the D phase will be described as a fourth driving pulse D4.

Referring to FIG. 6 , the first to fourth driving pulses D1 to D4 may have high sections HR at the same intervals that are sequentially continuous. In other words, a falling edge of the first driving pulse D1 and a rising edge of the second driving pulse D2 may occur at the same time point, and a falling edge of the second driving pulse D2 may occur at the same time. and the rising edge of the third driving pulse D3 may occur at the same time. Similarly, the falling edge of the third driving pulse D3 and the rising edge of the fourth driving pulse D4 may also occur at the same time. In addition, since the step motor 130 of the present invention is the four-phase step motor 130 , the falling edge of the fourth driving pulse D4 and the rising edge of the first driving pulse D1 may occur at the same time.

In this case, the driving circuit 120 may drive the step motor 130 in a one-phase excitation method in which a current flows only in a coil corresponding to one phase.

Hereinafter, an operation process of the step motor 130 driven according to the one-phase excitation method will be described in time series with reference to FIGS. 4 to 6 together. Meanwhile, in the following description, the teeth of the stator 131 are divided into first to fourth teeth 131a to 131d according to their positions.

In the first step, the first driving transistor Tr1 is turned on according to the first driving pulse D1 , and the A-phase current ia may flow through the coils A-A′ corresponding to the A-phase. Accordingly, the first teeth (131a) and the third teeth (131c) may have an S pole and an N pole, respectively, and the N pole and the S pole of the rotor 132 are respectively the first teeth (131a) and It can rotate to be adjacent to the third tooth (131c).

In the second step, the second driving transistor Tr2 is turned on according to the second driving pulse D2 , and the B-phase current ib may flow through the coils B-B′ corresponding to the B-phase. Accordingly, the second teeth (131b) and the fourth teeth (131d) may have an S pole and an N pole, respectively, and the N pole and the S pole of the rotor 132 are respectively the second teeth (131b) and It can rotate to be adjacent to the fourth tooth (131d).

In the third step, the third driving transistor Tr3 is turned on according to the third driving pulse D3 and the C-phase current ic may flow through the coils C-C′ corresponding to the C-phase. Accordingly, the first teeth (131a) and the third teeth (131c) may have an N pole and an S pole, respectively, and the N pole and the S pole of the rotor 132 are the third teeth 131c and It can rotate to be adjacent to the first tooth (131a).

In the last step, the fourth driving transistor Tr4 is turned on according to the fourth driving pulse D4 and the D-phase current id may flow through the coils D-D′ corresponding to the D-phase. Accordingly, the second teeth (131b) and the fourth teeth (131d) may have an N pole and an S pole, respectively, and the N pole and the S pole of the rotor 132 are respectively a fourth tooth (131d) and It can rotate to be adjacent to the second tooth (131b).

According to each of the steps described above, the rotor 132 may rotate at intervals of 90 degrees inside the stator 131 , and by repeating the above four steps, the rotor 132 may continuously rotate.

Meanwhile, referring to FIG. 7 , the first to fourth driving pulses D1 to D4 may have high sections HR at the same interval that are sequentially overlapped. In other words, the first to fourth driving pulses D1 to D4 sequentially have a high section HR, and a rising edge of the second driving pulse D2 in the high section HR of the first driving pulse D1. may occur, and a rising edge of the third driving pulse D3 may occur in the high period HR of the second driving pulse D2 . Similarly, a rising edge of the fourth driving pulse D4 may occur in the high period HR of the third driving pulse D3 . In addition, since the step motor 130 of the present invention is the four-phase step motor 130 , a rising edge of the first driving pulse D1 may occur in the high section HR of the fourth driving pulse D4 .

In this case, the driving circuit 120 sequentially flows currents in a coil corresponding to a specific phase and two coils corresponding to a specific phase and a phase adjacent to the specific phase, respectively, in a 1-2 phase excitation method for the step motor 130 ) can be driven.

Hereinafter, an operation process of the step motor 130 driven according to the 1-2 phase excitation method will be described in time series with reference to FIGS. 4, 5 and 7 together.

In the first step, the first driving transistor Tr1 is turned on according to the first driving pulse D1 , and the A-phase current ia may flow through the coils A-A′ corresponding to the A-phase. Accordingly, the first teeth (131a) and the third teeth (131c) may have an S pole and an N pole, respectively, and the N pole and the S pole of the rotor 132 are respectively the first teeth (131a) and It can rotate to be adjacent to the third tooth (131c).

In the second step, when the first driving transistor Tr1 is in the turned-on state, the second driving transistor Tr2 is turned on according to the second driving pulse D2 and the coils B-B' corresponding to the phase B are turned on. ), a B-phase current (ib) may flow. Accordingly, the first and second teeth 131a and 131b may exhibit S-pole magnetism, and the third and fourth teeth 131c and 131d may exhibit N-pole magnetism. The N and S poles of the rotor 132 may rotate 45 degrees clockwise for the first step.

In the third step, when the second driving transistor Tr2 is turned on, the first driving transistor Tr1 is turned off so that current can flow only through the coils B-B′ corresponding to the B-phase. Accordingly, the second teeth (131b) and the fourth teeth (131d) may have an S pole and an N pole, respectively, and the N pole and the S pole of the rotor 132 are respectively the second teeth (131b) and It can rotate to be adjacent to the fourth tooth (131d).

In the fourth step, when the second driving transistor Tr2 is in the turned-on state, the third driving transistor Tr3 is turned on according to the third driving pulse D3 and the coil C-C' corresponding to the C phase ), a C-phase current (ic) may flow. Accordingly, the second and third teeth 131b and 131c may exhibit S-pole magnetism, and the first and fourth teeth 131a and 131d may exhibit N-pole magnetism. The N and S poles of the rotor 132 may rotate 45 degrees clockwise for the third step.

That is, the teeth of the stator 131 having an S pole in the 1-2 phase excitation method are first teeth 131a, first and second teeth 131a and 131b, second teeth 131b, second and second teeth. 3 teeth (131b, 131c), 3rd teeth (131c), 3rd and 4th teeth (131c, 131d), 4th teeth (131d), 4th and 1st teeth (131d, 131a) in eight steps By sequentially switching accordingly, the rotor 132 can rotate 45 degrees clockwise in each step, and by repeating these eight steps, the rotor 132 can continuously rotate.

In this 1-2-phase excitation method, since the step angle of the rotor 132 is smaller than the above-described 1-phase excitation method, over shoot and under shoot are reduced when the rotor 132 is stopped. It is relatively small, and the transient characteristic is improved.

Meanwhile, the controller 110 outputs the first and second control pulses S1 and S2 having different high sections HR through the two output terminals #1 and #2, respectively, and the two output terminals #1 , #2) and the relay 150 selectively connecting any two input terminals of the driving circuit 120 may be controlled to provide each driving pulse D1 to D4 to the driving circuit 120 .

The controller 110 may be a microcontroller unit (MCU) that outputs a signal through a plurality of output terminals (eg, a port, a pin, etc.). The controller 110 of the present invention may include at least three output terminals #1 to #3, and transmits the first and second control pulses S1 and S2 through the two output terminals #1 and #2. output, and the relay 150 may be controlled through one output terminal #3.

The relay 150 includes any two input terminals of the four input terminals #1 ' to #4' of the driving circuit 120 and two output terminals #1 of the controller 110 according to the control of the controller 110 . #2) can be optionally connected. For example, the relay 150 connects the two output terminals #1 and #2 of the controller 110 to any two input terminals among the four input terminals #1' to #4' of the driving circuit 120 according to its operation state. can be connected with or with the other two inputs.

More specifically, the controller 110 provides the relay 150 with a switching pulse Sp having a high value (H) or a low value (L), and the relay 150 causes the switching pulse Sp to a high value ( H) when the two output terminals #1 and #2 of the controller 110 and any two input terminals of the driving circuit 120 are connected, and when the switching pulse Sp has a low value L, the controller ( The two output terminals #1 and #2 of 110 and the other two input terminals #1' to #4' of the driving circuit 120 may be connected.

Referring to FIG. 8 , the switching pulse Sp output from the controller 110 may have a rectangular shape having a high value (H) or a low value (L). The relay 150 may change a state according to the magnitude of the applied voltage, thereby connecting the output terminals #1 and #2 of the controller 110 and the input terminal of the driving circuit 120 .

Referring to FIGS. 9A and 9B , the relay 150 is a driving circuit 120 to which the first and second driving pulses D1 and D2 are input when the switching pulse Sp is a low value (L). It may be connected to the first and second input terminals #1' and #2'. Conversely, the relay 150 has the third and fourth input terminals #3' and # of the driving circuit to which the third and fourth driving pulses D3 and D4 are input when the switching pulse Sp is the high value H. 4') can be connected.

More specifically, the relay 150 includes a first relay 151 provided at the first output terminal #1 to which the first control pulse S1 is output, and a second output terminal to which the second control pulse S2 is output. It may be configured by the second relay 152 provided in (#2).

At this time, the first relay 151 may connect the first output terminal #1 and the second input terminal #2' when the switching pulse Sp is the low value L, and the switching pulse Sp At the high value H, the first output terminal #1 and the third input terminal #3' may be connected. In addition, the second relay 152 may connect the second output terminal #2 and the second input terminal #2' when the switching pulse Sp is the low value L, and the switching pulse Sp is the high When the value is H, the second output terminal #2 and the fourth input terminal #4' may be connected.

Meanwhile, according to the operation state of the relay 150 , the two output terminals #1 and #2 of the controller 110 may be connected to any two input terminals of the driving circuit 120 .

The first and second control pulses S1 and S2 may be generated to have different high periods HR and may be output through respective output terminals #1 and #2. Here, the different high sections HR may mean that the high sections HR are formed at different times, not that the high sections HR have different widths. That is, the first and second control pulses S1 and S2 may be generated so that the high period HR is shifted from each other within one period, and may be output through the respective output terminals #1 and #2.

Referring to FIG. 10 , in an example, the first and second control pulses S1 and S2 may have the same pulse period T and duty ratio, and the second control pulse S2 may include the first control pulse S1 . ) may have a rising edge at the falling edge. That is, the first and second control pulses S1 and S2 may be generated to have a duty ratio of 50% in the same pulse period T and to have a high period HR shifted from each other.

At this time, the controller 110 controls the relay 150 at the same period as the pulse period T of the first and second control pulses S1 and S2 to generate the first and second control pulses S1 and S2. It may be provided to the driving circuit 120 through the input terminals #1' to #4'. To this end, the period of the switching pulse Sp may be the same as the pulse period T of the first and second control pulses S1 and S2.

Accordingly, whenever one pulse period T of the first and second control pulses S1 and S2 elapses, the operation state of the relay 150 may be switched, and the first and second control pulses S1 and S2 S2) may be alternately provided to any two input terminals and the other input terminals of the driving circuit 120 .

More specifically, the operation state of the relay 150 may be switched at time points t1, t2, and t3 at which the rising edge of the first control pulse S1 and the falling edge of the second control pulse S2 coincide. That is, the time point at which the value of the switching pulse Sp changes may be the time point ( t1 , t2 , t3 ) at which the rising edge of the first control pulse S1 and the falling edge of the second control pulse S2 coincide.

9A, 9B, and 10 together, when the switching pulse Sp is a low value (L), the first and second control pulses S1 and S2 are the first and second control pulses of the driving circuit 120 . It may be output to the input terminals #1' and #2'. Accordingly, in the first pulse period T, the first and second driving pulses D1 and D2 may be the same as the first and second control pulses S1 and S2, respectively. In this case, the control pulse may not be provided to the third and fourth input terminals #3' and #4' in the open state.

Subsequently, when the switching pulse Sp is switched to the high value H, the first and second control pulses S1 and S2 are applied to the third and fourth input terminals #3' and #4' of the driving circuit 120 . can be output as Accordingly, in the second pulse period T, the third and fourth driving pulses D3 and D4 may be the same as the first and second control pulses S1 and S2, respectively. In this case, the control pulse may not be provided to the first and second input terminals #1' and #2' in the open state.

Subsequently, when the switching pulse Sp is switched back to the low value L, the first and second control pulses S1 and S2 are again applied to the first and second input terminals #1' and #2 of the driving circuit 120 . ') can be output. Accordingly, in the third pulse period T, the first and second driving pulses D1 and D2 may be the same as the first and second control pulses S1 and S2, respectively. As described above, the control pulse may not be provided to the third and fourth input terminals #3' and #4' in the open state.

As described above, by alternately providing the first and second control pulses S1 and S2 to any two input terminals of the driving circuit 120 through the relay 150, the first to fourth driving pulses D1 to D4 are As shown in FIG. 6 , it may have a high section HR of the same interval consecutively and continuously, and accordingly, the stepper motor 130 may be driven in the above-described one-phase excitation method.

Referring to FIG. 11 , in another example, the first and second control pulses S1 and S2 have the same pulse period T, but may have different duty ratios, and the high period of the first control pulse S1 is The high period HR2 of the HR1 and the second control pulse S2 may partially overlap. That is, the first and second control pulses S1 and S2 may be generated to have different duty ratios in the same pulse period T, and the respective high sections HR1 and HR2 may be partially shifted.

The duty ratio of the first control pulse S1 and the second control pulse S2 may be arbitrarily set by a user differently according to a control method of the step motor 130 . However, in the following description, it is assumed that the duty ratio of the first control pulse S1 is greater than the duty ratio of the second control pulse S2.

On the other hand, as in the above example, the relay 150 is controlled with the same period as the pulse period T of the first and second control pulses S1 and S2, and the operation state of the relay 150 is the first control pulse S1 ) may be switched at time points t1, t2, and t3 at which the rising edge of the second control pulse S2 coincides with the falling edge of the second control pulse S2.

Accordingly, when the duty ratio of the second control pulse S2 is smaller than the duty ratio of the first control pulse S1 , the second and fourth driving pulses D2 and D4 generated by the second control pulse S2 are may have a duty ratio smaller than that of the first and third driving pulses D1 and D3. Due to such an imbalance in the duty ratio of the driving pulses, an imbalance occurs in the current flowing in the coil corresponding to each phase, and in this case, the torque of the step motor 130 cannot be constantly maintained.

To prevent this, a capacitor for maintaining the voltage of the second control pulse S2 may be further provided at any two input terminals to which the second control pulse S2 is provided among the input terminals of the driving circuit 120 of the present invention.

Referring to FIG. 12 , the second control pulse S2 output through the second output terminal #2 of the controller 110 is the second input terminal # of the driving circuit 120 according to the operation state of the relay 150 . 2') or the fourth input terminal (#4'). In this case, capacitors C1 and C2 for maintaining the voltage of the second control pulse S2 may be provided at the second input terminal #2' and the fourth input terminal #4', respectively.

12 and 13 together, when the switching pulse Sp is a low value (L), the first and second control pulses S1 and S2 are applied to the first and second input terminals # of the driving circuit 120 . 1', #2'). Accordingly, in the first pulse period T, the first and second driving pulses D1 and D2 may be the same as the first and second control pulses S1 and S2, respectively. In this case, the first capacitor C1 provided at the second input terminal #2' may store the voltage of the second control pulse S2. Meanwhile, the control pulse may not be provided to the third and fourth input terminals #3' and #4' in the open state.

Subsequently, when the switching pulse Sp is switched to the high value H, the first and second control pulses S1 and S2 are applied to the third and fourth input terminals #3' and #4' of the driving circuit 120 . can be output as Accordingly, in the second pulse period T, the third and fourth driving pulses D3 and D4 may be the same as the first and second control pulses S1 and S2 . In this case, the second capacitor C2 provided at the fourth input terminal #4' may store the voltage of the second control pulse S2.

Meanwhile, although no control pulse is provided to the first and second input terminals #1' and #2' that are open in the second pulse period T, the first input terminal provided in the second input terminal #2' The capacitor C1 may output the voltage of the second control pulse S2 to the driving circuit 120 for a predetermined discharge time tc even after the switching pulse Sp is converted to the high value H. Accordingly, in the second pulse period T, the second driving pulse D2 may have a constant voltage value during the discharge time tc of the first capacitor C1 .

Subsequently, when the switching pulse Sp is switched back to the low value L, the first and second control pulses S1 and S2 are again applied to the first and second input terminals #1' and #2 of the driving circuit 120 . ') can be output. Accordingly, in the third pulse period T, the first and second driving pulses D1 and D2 may be the same as the first and second control pulses S1 and S2, respectively.

On the other hand, although no control pulse is provided to the third and fourth input terminals #3' and #4' that are open in the third pulse period T, the second input terminal provided in the fourth input terminal #4' The capacitor C2 may output the voltage of the second control pulse S2 to the driving circuit 120 for a predetermined discharge time tc even after the switching pulse Sp is converted to the low value L. Accordingly, in the third pulse period T, the fourth driving pulse D4 may have a constant voltage value during the discharge time tc of the second capacitor C2.

In this way, the first and second control pulses S1 and S2 are alternately provided to any two input terminals of the driving circuit 120 through the relay 150 and at the same time, a terminal to which a control pulse having a relatively small duty ratio is input. By providing a capacitor to generate a driving pulse even after the control pulse is blocked, the first to fourth driving pulses D1 to D4 have high sections HR of the same interval that are sequentially overlapped as shown in FIG. 7 . and, accordingly, the stepper motor 130 may be driven in the above-described 1-2 phase excitation method.

As a result, the present invention can save one or more ports compared to the prior art by reducing the number of ports required to control the step motor 130 through the relay 150 control, and accordingly, the printed circuit board (PCB) of the step motor driving device 100 Circuit Board) has the advantage of cost reduction and mounting of additional functions.

In addition, the present invention has the advantage of enabling efficient driving of the step motor 130 while saving ports by driving the step motor 130 in a 1-2 phase excitation method through two control signals.

For those of ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible within the scope of the present invention without departing from the technical spirit of the present invention. is not limited by

Claims (10)

a step motor including a stator in which a coil corresponding to each of four phases is wound, and a rotor disposed in the stator and rotated by a magnetic field generated from the coil;
a driving circuit for supplying current to each coil wound around the stator by operating according to each driving pulse provided through the four input terminals; and
Each of the first and second control pulses having different high sections is output through two output terminals, and a relay selectively connecting the two output terminals and any two input terminals of the driving circuit is controlled to provide the driving circuit with the respective driving a controller for providing a pulse;
The first and second control pulses have the same pulse period and duty ratio, and the second control pulse has a rising edge from a falling edge of the first control pulse.
According to claim 1,
and the driving circuit includes a driving transistor configured to supply a current supplied from a driving power supply to the coil by switching according to the driving pulse.
3. The method of claim 2,
The driving pulse is applied to the gate terminal of the driving transistor,
The driving transistor is a step motor driving device for connecting the driving power and the coil in a high section of the driving pulse.
According to claim 1,
The driving circuit is a step motor driving device for supplying current to each of the coils by operating according to driving pulses for each phase sequentially having a high section of the same interval.
According to claim 1,
the controller provides a switching pulse having a high value or a low value to the relay;
The relay connects the two output terminals of the controller and any two input terminals of the driving circuit when the switching pulse has a high value, and connects the two output terminals of the controller and the driving circuit when the switching pulse has a low value. A stepper motor drive that connects the other two inputs.
According to claim 1,
The operation state of the relay is switched when a rising edge of the first control pulse coincides with a falling edge of the second control pulse.
According to claim 1,
The controller controls the relay with the same period as the pulse period of the first and second control pulses to provide the first and second control pulses to the driving circuit through four input terminals.
delete a step motor including a stator in which a coil corresponding to each of four phases is wound, and a rotor disposed in the stator and rotated by a magnetic field generated from the coil;
a driving circuit for supplying current to each coil wound around the stator by operating according to each driving pulse provided through the four input terminals; and
Each of the first and second control pulses having different high sections is output through two output terminals, and a relay selectively connecting the two output terminals and any two input terminals of the driving circuit is controlled to provide the driving circuit with the respective driving a controller for providing a pulse;
The first and second control pulses have the same pulse period and different duty ratios, and a high section of each of the first and second control pulses partially overlaps.
10. The method of claim 9,
a duty ratio of the first control pulse is greater than a duty ratio of the second control pulse;
A capacitor for maintaining the voltage of the second control pulse is further provided at any two input terminals to which the second control pulse is provided among the input terminals of the driving circuit.

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