TWI767735B - Motor control circuit - Google Patents

Abstract

A motor control circuit is provided to solve the problem that the conventional motor control circuit is susceptible to power fluctuations and results in operation stability reduced. It comprises: a switching unit, with a power connection terminal for electrically connecting a power source, and two motor connection terminals for electrically connecting a motor coil. The switching unit also has a control voltage unit for controlling the time of current output to the motor coil; and a control module with an input terminal electrically connecting the power connection terminal, a voltage regulator assembly electrically connects the input terminal and an output terminal, the voltage regulator assembly maintains the voltage of the output terminal at a target voltage, and the output terminal electrically connects the control voltage unit.

Description

motor control circuit

The present invention relates to a circuit structure, especially a motor control circuit.

A general single-phase DC brushless motor drives a rotor to rotate with a magnetic field change by energizing the motor coil. Please refer to FIG. 1, which is a conventional motor control circuit 9. The motor control circuit 9 usually has a drive circuit 91 formed by four transistors and a motor coil M electrically connected. The drive circuit 91 It is electrically connected to a power source E through a power source connection terminal 92 so that the motor coil M is driven by a current. The motor control circuit 9 further has a pulse width modulation circuit 93 , and the pulse width modulation circuit 93 can be used to generate a pulse width modulation signal, and the pulse width modulation signal can control the conduction of the transistor of the driving circuit 91 or cut-off state, and then control the time when the current is input to the motor coil M, thereby making the motor coil M change the magnetic pole and push the rotor of the motor to rotate. The motor control circuit 9 also has a voltage divider circuit 94, the voltage divider circuit 94 is electrically connected to the power source E, the voltage divider circuit 94 has a resistor R1 to divide the voltage of the power source E, and the resistor R1 divides the voltage of the power source E. The divided voltage of the power supply E is a control voltage V. After the control voltage V is input to the pulse width modulation circuit 93 through a voltage connection terminal 95, the pulse width modulation signal can be formed. The driving circuit 91 can generate the pulse width modulation signal according to the pulse width. The modulation signal outputs current to the motor coil M.

Please refer to FIG. 2 , which is a comparison diagram of the control voltage V and a pulse width modulation signal C. FIG. The pulse width modulation circuit 93 has a reference voltage S inside, the reference voltage S is input to the non-inverting (+) terminal of a comparator P (as shown in FIG. 1 ), and the reference voltage S is For a fixed period triangular wave, the control voltage V is compared with the reference voltage S, and the pulse width modulation circuit 93 outputs the pulse width modulation signal C at an output terminal 96 (as shown in FIG. 1 ). In a cycle of the reference voltage S, when the control voltage V is greater than the reference voltage S, the PWM signal C enters a high-level duty cycle D; when the control voltage V is less than the reference voltage S, The PWM signal C enters a low-level rest period, so that the PWM signal C forms a square wave. It can be seen from the figure that a larger control voltage V can make the PWM signal C have a longer duty cycle D, that is, a longer time for the current to output the motor coil M. Referring to FIG. 1 again, since the control voltage V is the voltage divided by the resistor R1 of the voltage dividing circuit 94 to the power supply E, the control voltage V varies with the power supply E.

In the above-mentioned conventional motor control circuit 9, since the control voltage V can be changed by the influence of the power source E, the duty cycle D of the PWM signal C is easily changed due to the instability of the power source E, that is, the change The time for the current to be output to the motor coil M is shortened, thereby reducing the stability of the motor operation.

In view of this, it is still necessary to improve the conventional motor control circuit.

In order to solve the above problems, the purpose of the present invention is to provide a motor control circuit in which the pulse width modulation signal can be changed without being affected by the power supply.

The use of the quantifier "a" or "an" for the elements and components described throughout the present invention is only for convenience and provides a general meaning of the scope of the present invention; in the present invention, it should be construed as including one or at least one, and a single The concept of also includes the plural case unless it is obvious that it means otherwise.

The motor control circuit of the present invention includes: a switching unit having a power connection end for electrically connecting a power source, and two motor connection ends for electrically connecting a motor coil, the two motor The connection end is electrically connected to the power connection end, the switching unit also has a control voltage unit for controlling the time when the current is output to the motor coil; and a control module, which has an input end electrically connected to the power connection end , the input end is connected in parallel with an energy storage element, a voltage stabilization component is electrically connected to the input end and an output end, the voltage stabilization component stabilizes the voltage of the output end at a target voltage, and the output end is electrically connected to the control voltage unit .

The motor control circuit of the present invention includes: a switching unit having a power connection end for electrically connecting a power source, and two motor connection ends for electrically connecting a motor coil, the two motor connection ends are electrically connected to the power source a connection end, the switching unit also has a control voltage unit for controlling the time when the current is output to the motor coil; and a control module, which has an input end electrically connected to the power supply connection end, and a voltage stabilizing component electrically connected The input end and an output end, the output end is connected in parallel with an energy storage element, the voltage stabilization component stabilizes the voltage of the output end at a target voltage, and the output end is electrically connected to the control voltage unit.

The motor control circuit of the present invention includes: a switching unit having a power connection end for electrically connecting a power source, and two motor connection ends for electrically connecting a motor coil, the two motor connection ends are electrically connected to the power source a connection end, the switching unit also has a control voltage unit for controlling the time when the current is output to the motor coil; and a control module, which has an input end electrically connected to the power supply connection end, and a voltage stabilizing component electrically connected The input end and an output end, the voltage stabilization component includes a resistor, a transistor and a sensor diode, the voltage stabilization component stabilizes the voltage of the output end at a target voltage, and the output end is electrically connected to the control voltage unit.

Accordingly, the motor control circuit of the present invention has the voltage-stabilizing component, and the voltage-stabilizing component can make the output end of the control module provide a stable voltage to the control voltage unit, thereby enabling the current to be output to the motor coil. The time is fixed, which can improve the stability of the motor operation.

Wherein, the switching unit may be an integrated circuit element. In this way, the occupied space of the switching unit can be reduced, which has the effect of miniaturizing the motor control circuit.

Wherein, the voltage-stabilizing component can be a diode. In this way, the function of voltage regulation can be achieved with simple components, which has the effect of simplifying the circuit structure of the control module.

Wherein, the voltage stabilization component is an integrated circuit element. In this way, the integrated circuit device can not only increase the output current, but also reduce the occupied space, which has the effect of miniaturizing the motor control circuit.

Wherein, the voltage regulator component is a low dropout voltage regulator. In this way, the control module can stabilize the output end at the target voltage by using a lower input voltage, which has the effect of reducing the power consumption of the circuit.

〔this invention〕

1: Switch unit

11: Power connector

12: Motor connection end

13: Control voltage unit

2: Control module

21: Input terminal

22: Voltage Stabilizer Components

23: output terminal

24: Energy storage element

C: Control signal

D: duty cycle

E: Power

G1, G2: Curve

M: motor coil

Q: Transistor

R: resistance

S: reference voltage

U1, U2: Integrated circuit components

U3: Low dropout regulator

Z: Ziner diode

(accustomed)

9: Motor control circuit

91: Drive circuit

92: Power connector

93: Pulse width modulation circuit

94: Voltage divider circuit

95: Control voltage connection terminal

96: output terminal

C: PWM signal

D: duty cycle

E: Power

M: motor coil

P: Comparator

R1: Resistor

S: reference voltage

V: Control voltage

[Fig. 1] A circuit diagram of a conventional motor control circuit.

[Fig. 2] A comparison diagram of the control voltage of the conventional motor control circuit and the waveform of the PWM signal.

[FIG. 3] A circuit diagram of the first embodiment of the present invention.

[FIG. 4] A comparison diagram of the output terminal voltage and the control signal waveform according to the first embodiment of the present invention.

[FIG. 5] A circuit diagram of a second embodiment of the present invention.

[FIG. 6] A circuit diagram of a third embodiment of the present invention.

[FIG. 7] A circuit diagram of a fourth embodiment of the present invention.

In order to make the above-mentioned and other objects, features and advantages of the present invention more obvious and easy to understand, the preferred embodiments of the present invention are given below, and the accompanying drawings are described in detail as follows: please refer to Figure 3, It is the first embodiment of the motor control circuit of the present invention, It includes a switch unit 1 and a control module 2 , and the control module 2 is electrically connected to the switch unit 1 .

The switching unit 1 has a power connection end 11 and two motor connection ends 12. The power connection end 11 is used for connecting a power source E, the power source E is a DC power supply source, and the two motor connection ends 12 are electrically connected to the power source E. The power supply connection terminal 11 is used to guide the current provided by the power supply E. A motor coil M is electrically connected between the two motor connection ends 12 , so that the current of the power source E passes through the motor coil M. The switching unit 1 also has a control voltage unit 13 , and the control voltage unit 13 is used for generating a control signal, and the control signal can be used to control the time when the current is outputted to the motor coil M.

Specifically, in this embodiment, the switching unit 1 may have a drive circuit (not shown) composed of transistors, and the drive circuit is electrically connected to the two motor connection terminals 12 , and the control voltage unit 13 may be A pulse width modulation circuit composed of components such as operational amplifiers and oscillators can be used to generate the control signal. The control signal can be a pulse width modulation signal. The control voltage unit 13 outputs the control signal to the control signal. Drive circuit. Preferably, the switching unit 1 can be an integrated circuit element U1, and the above-mentioned driving circuit and the control voltage unit 13 can be integrated into the integrated circuit element U1, thereby reducing the occupied space of the switching unit 1 . The integrated circuit element U1 can be in various conventional packaging forms, which are not limited in the present invention. In this embodiment, the integrated circuit element U1 may have a VDD pin, an M1 pin, an M2 pin and a VC pin, the VDD pin is the power connection terminal 11 ; the M1 pin and The M2 pin is the two motor connection ends 12 ; the VC pin is electrically connected to the control voltage unit 13 . The integrated circuit element U1 also has a VSS pin for electrically connecting to a common terminal. In this embodiment, the common terminal may be a ground terminal. In this way, the integrated circuit element U1 can control the time during which the current is output to the motor coil M by inputting the voltage of the VC pin.

The control module 2 has an input end 21 , and the input end 21 is electrically connected to the power supply E. The control module 2 also has a voltage-stabilizing component 22 , and the voltage-stabilizing component 22 is electrically connected to the input end 21 and an output end 23 , the voltage stabilization component 22 stabilizes the voltage of the output end 23 to a target voltage, and the output end 23 is electrically connected to the control voltage unit 13 .

In this embodiment, the control module 2 may have a resistor R, one end of the resistor R is the input end 21 of the control module 2 , and the other end of the resistor R is electrically connected to the output end of the control module 2 twenty three. The voltage-stabilizing component 22 can be a Zener diode Z, which can achieve the function of voltage-stabilizing with simple components. The specification of the Zener diode Z is not limited in the present invention, and is in the art Those with general knowledge can choose according to the needs of the target voltage. The cathode of the Zener diode Z is electrically connected to the output terminal 23 , and the anode of the Zener diode Z is connected to the ground terminal. Therefore, when the voltage of the power supply E makes the Zener diode Z in a reverse bias collapse state, the voltage of the output terminal 23 can be stabilized at the reverse collapse voltage of the Zener diode Z, and the reverse The breakdown voltage is equal to the set target voltage. Even if the voltage of the power supply E changes, the output terminal 23 can stably provide a fixed voltage to the VC pin of the integrated circuit element U1 . The resistor R can provide a voltage drop effect on the power supply E, thereby preventing the Zener diode Z in a reverse bias breakdown state from being damaged by excessive current.

Referring to Figures 3 and 4, the curve G1 represents the voltage change state of the power supply E, and the curve G2 represents the voltage change state of the output end 23 of the control module 2 (ie the VC input to the integrated circuit element U1). voltage change status of the pin). In this embodiment, the voltage of the power supply E (curve G1 ) is gradually reduced from 24V to 12V, and the voltage of the output end 23 (curve G2 ) is always maintained at 2.7V. It can be seen that the voltage of the output end 23 is It can be stably supplied to the VC pin (the control voltage unit 13 ) of the integrated circuit element U1 without being affected by the variation of the power supply E. Thereby, the control voltage unit 13 can compare an internal reference voltage S with the voltage of the output terminal 23 to generate a control signal C, and the control signal C has a consistent duty cycle D, that is, even if the current is output to The time of the motor coil M is fixed.

Please refer to FIG. 5, which is a second embodiment of the motor control circuit of the present invention. Compared with the first embodiment, in this embodiment, the control module 2 may have a transistor Q, and the voltage regulator component 22 may include the transistor Q and the Zener diode Z, the transistor Q Various conventional transistors can be used, which is not limited in the present invention. The transistor Q can be an NPN bipolar transistor (BJT), the collector of the transistor Q is electrically connected to the input terminal 21, the base of the transistor Q is electrically connected to the cathode of the Zener diode Z, The emitter of the transistor Q is electrically connected to the output terminal 23 instead of the cathode of the Zener diode Z, and the resistor R is connected between the collector and the base of the transistor Q. Therefore, in addition to maintaining a stable voltage, the output terminal 23 can provide a higher output current through the transistor Q. Preferably, the input end 21 and the output end 23 can respectively connect an energy storage element 24 in parallel, and the energy storage element 24 can be a capacitor. In this way, the voltage input to the input terminal 21 and the VC pin can be reduced from noise interference.

Please refer to FIG. 6, which is a third embodiment of the motor control circuit of the present invention. Compared with the second embodiment, the voltage stabilizing component 22 can be an integrated circuit element U2 with a smaller volume, and the integrated circuit element U2 has the transistor Q, the Zener diode Z and the resistor R. The integrated circuit element U2 can be, for example, a ZXTR2105. The integrated circuit element U2 has a Vout pin, a Vin pin and a GND pin. The Vin pin is electrically connected to the input end 21 ; the Vout pin is electrically connected to the output terminal 23; the GND pin is connected to the ground terminal. In this way, the integrated circuit element U2 can not only increase the output current, but also reduce the occupied space.

Please refer to FIG. 7, which is a fourth embodiment of the motor control circuit of the present invention. In this embodiment, the voltage-stabilizing component 22 can be a low-dropout voltage regulator (LDO) U3, which can still operate under the condition that the voltage of the input terminal 21 and the target voltage have a low dropout voltage. In this way, The input 21 can use a lower voltage. The low dropout voltage regulator U3 has a Vcc pin, an OUT pin and a GND pin. The Vcc pin is electrically connected to the input end 21; the OUT pin is electrically connected to the output end 23; pin is connected to ground. Therefore, the control module 2 can stabilize the output terminal 23 at the target voltage by using a lower input voltage.

To sum up, the motor control circuit of the present invention has the voltage-stabilizing component, and the voltage-stabilizing component can enable the output end of the control module to provide a stable voltage to the control voltage unit, thereby enabling the current to be output to the motor The time of the coil is fixed, which can improve the stability of the motor operation. In addition, the switching unit and the voltage-stabilizing component can be respectively integrated circuit components, so that the switching unit and the voltage-stabilizing component can reduce the occupied space, and have the effect of miniaturizing the motor control circuit.

Although the present invention has been disclosed by the above-mentioned preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications relative to the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the patent application attached hereto.

1: Switch unit

11: Power connector

12: Motor connection end

13: Control voltage unit

2: Control module

21: Input terminal

22: Voltage Stabilizer Components

23: output terminal

E: Power

M: motor coil

R: resistance

U1: Integrated Circuit Components

Z: Ziner diode

Claims (7)

A motor control circuit, comprising: a switching unit having a power connection end for electrically connecting a power supply, and two motor connection ends for electrically connecting a motor coil, the two motor connection ends are electrically connected to the power supply connection end , the switching unit also has a control voltage unit for controlling the time when the current is output to the motor coil; and a control module, which has an input terminal electrically connected to the power connection terminal, the input terminal is connected in parallel with an energy storage element, A voltage stabilization component is electrically connected to the input end and an output end, the voltage stabilization component stabilizes the voltage of the output end at a target voltage, and the output end is electrically connected to the control voltage unit. A motor control circuit, comprising: a switching unit having a power connection end for electrically connecting a power supply, and two motor connection ends for electrically connecting a motor coil, the two motor connection ends are electrically connected to the power supply connection end , the switching unit also has a control voltage unit for controlling the time when the current is output to the motor coil; and a control module with an input terminal electrically connected to the power connection terminal, and a voltage regulator component electrically connected to the input terminal and an output terminal, the output terminal is connected in parallel with an energy storage element, the voltage stabilization component stabilizes the voltage of the output terminal at a target voltage, and the output terminal is electrically connected to the control voltage unit. The motor control circuit of claim 1 or 2, wherein the voltage regulator component is a low dropout voltage regulator. The motor control circuit of claim 1 or 2, wherein the voltage regulator component is a zener diode. A motor control circuit, comprising: a switching unit having a power connection end for electrically connecting a power supply, and two motor connection ends for electrically connecting a motor coil, the two motor connection ends are electrically connected to the power supply connection end , the switching unit also has a control voltage unit, used to control the time when the current is output to the motor coil; and a control module, which has an input terminal electrically connected to the power connection terminal, and a voltage regulator component electrically connected The input end and an output end, the voltage stabilization component includes a resistor, a transistor and a sensor diode, the voltage stabilization component stabilizes the voltage of the output end at a target voltage, and the output end is electrically connected to the control voltage unit. The motor control circuit of claim 5, wherein the voltage regulator component is an integrated circuit element. The motor control circuit of claim 1, 2 or 5, wherein the switching unit is an integrated circuit element.

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