A PWM control power conversion circuit for a DC brush motor

Abstract

The application provides a DC brush motor PWM control power conversion circuit, characterized in that the conversion circuit comprises current-limiting resistors R1 and R2, a first pair of switching elements Q1 and Q2, power resistors R3 and R4, a first pair of voltage division resistors R5 and R6, a second pair of voltage division resistors R7 and R8, a first pair of anti-reverse diodes D3 and D4, a second pair of anti-reverse diodes D1 and D2, an anti-reverse diode D5, a filter capacitor C1, voltage stabilizing diodes Z1 and Z2, and a second pair of switching elements T1 and T2. The circuit can convert PWM wave input into power output, and can realize positive and negative rotation control and speed regulation of the motor through the on-off cooperation of the two pairs of switching elements, and has a simple and practical structure.

Description

Technical Field

[0001] This invention belongs to the field of servo control technology, specifically relating to a DC brushed motor PWM control power conversion circuit. Background Technology

[0002] A brushed DC motor is a type of DC motor widely used due to its simple structure, stable performance, fast response, and high starting torque. The stator of a brushed DC motor has fixed main magnetic poles and brushes, while the rotor has armature windings and a commutator. Electrical energy from a DC power supply enters the armature windings through the brushes and commutator, generating armature current. The magnetic field generated by this armature current interacts with the main magnetic field to produce electromagnetic torque, causing the motor to rotate and drive the load.

[0003] The forward / reverse control of a brushed DC motor is achieved through two sets of triggering devices. The forward and reverse rotation is controlled by changing the positive and negative voltages applied to the motor terminals. Speed ​​regulation of a brushed DC motor typically uses voltage regulation. Traditional speed control methods generally employ only a single switching element such as a MOSFET, directly chopping the motor power supply via a PWM wave to adjust the speed, thus altering the effective value of the voltage applied to the brushed DC motor. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a PWM power conversion circuit and driving method, thereby amplifying the power of the PWM control signal and solving the problems of reliable forward / reverse control and speed regulation of DC brushed motors.

[0005] The present invention aims to provide a PWM control power conversion circuit for a DC brushed motor. The conversion circuit includes: current-limiting resistors R1 and R2, a first pair of switching elements Q1 and Q2, power resistors R3 and R4, a first pair of voltage divider resistors R5 and R6, a second pair of voltage divider resistors R7 and R8, a first pair of anti-reverse diodes D3 and D4, a second pair of anti-reverse diodes D1 and D2, an anti-reverse diode D5, a filter capacitor C1, Zener diodes Z1 and Z2, and a second pair of switching elements T1 and T2.

[0006] In this configuration, the common terminal of current-limiting resistors R1 and R2 is connected to the positive terminal of the 28V power supply and the first terminal of filter capacitor C1. The second terminal of filter capacitor C1 is connected to the base of the first pair of switching elements Q1 and Q2, respectively.

[0007] The first pair of switching elements Q1 and Q2 are connected in series. The emitters of the first pair of switching elements Q1 and Q2 are connected to the positive terminal of a 28V power supply, and their bases respectively receive the ground / on logic signal Uin. The ground / on logic signals received by the bases of the first pair of switching elements Q1 and Q2 are mutually exclusive.

[0008] The first terminals of the power resistors R3 and R4 are connected to the first terminals of the first pair of voltage divider resistors R5 and R6, and the second terminals of the power resistors R3 and R4 are connected to the positive terminals of the second pair of anti-reverse diodes D1 and D2.

[0009] The first terminals of the first pair of voltage divider resistors R5 and R6 are also connected to the collectors of the first pair of switching elements Q1 and Q2, and the second terminals of the first pair of voltage divider resistors R5 and R6 are connected to the positive terminals of the first pair of anti-reverse diodes D3 and D4.

[0010] The first terminals of the second pair of voltage divider resistors R7 and R8 are connected to the cathodes of the first pair of anti-reverse diodes D3 and D4, as well as the cathodes of the Zener diodes Z1 and Z2. The second terminals of the second pair of voltage divider resistors R7 and R8 are connected to the anode of the anti-reverse diode D5.

[0011] The positive terminals of the second pair of anti-reverse diodes D1 and D2 are connected to the second terminals of power resistors R3 and R4, and the negative terminals of the second pair of anti-reverse diodes D1 and D2 are connected to the gates of the second pair of switching elements T1 and T2.

[0012] The positive terminal of the anti-reverse diode D5 is also connected to the second terminal of the filter capacitor C1, the positive terminals of the Zener diodes Z1 and Z2, and the drain of the second pair of switching elements T1 and T2.

[0013] The gates of the second pair of switching elements T1 and T2 are connected to the positive terminals of Zener diodes Z1 and Z2, respectively, and the source is also connected to the first terminal of a DC brushed motor.

[0014] The DC brushed motor PWM control power conversion circuit provided by the present invention also has the following feature: the first pair of switching elements Q1 and Q2 are PNP transistors.

[0015] The DC brushed motor PWM control power conversion circuit provided by the present invention also has the following feature: the second pair of switching elements T1 and T2 are N-type MOS transistors.

[0016] Beneficial effects:

[0017] The DC brushed motor PWM control power conversion circuit provided by this invention can convert PWM wave input into power output. Through the switching of two pairs of switching elements, the forward and reverse rotation control and speed regulation of the motor can be realized. The structure is simple and practical. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the DC brushed motor PWM control power conversion circuit provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments, in conjunction with the accompanying drawings, provide a detailed description of the DC brushed motor PWM control power conversion circuit provided by this invention.

[0021] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0022] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0024] like Figure 1 As shown, a DC brushed motor PWM control power conversion circuit is provided. The conversion circuit includes: current-limiting resistors R1 and R2, a first pair of switching elements Q1 and Q2, power resistors R3 and R4, a first pair of voltage divider resistors R5 and R6, a second pair of voltage divider resistors R7 and R8, a first pair of reverse protection diodes D3 and D4, a second pair of reverse protection diodes D1 and D2, a reverse protection diode D5, a filter capacitor C1, Zener diodes Z1 and Z2, and a second pair of switching elements T1 and T2.

[0025] In this configuration, the common terminal of current-limiting resistors R1 and R2 is connected to the positive terminal of the 28V power supply and the first terminal of filter capacitor C1. The second terminal of filter capacitor C1 is connected to the base of the first pair of switching elements Q1 and Q2, respectively.

[0026] The first pair of switching elements Q1 and Q2 are connected in series. The emitters of the first pair of switching elements Q1 and Q2 are connected to the positive terminal of a 28V power supply, and their bases respectively receive the ground / open logic signal Uin. The ground / open logic signals received by the bases of the first pair of switching elements Q1 and Q2 are mutually exclusive, that is, when the base of Q1 is in "ground" logic, the base of Q2 is in "open" logic, and vice versa.

[0027] The first terminals of the power resistors R3 and R4 are connected to the first terminals of the first pair of voltage divider resistors R5 and R6, and the second terminals of the power resistors R3 and R4 are connected to the positive terminals of the second pair of anti-reverse diodes D1 and D2.

[0028] The first terminals of the first pair of voltage divider resistors R5 and R6 are also connected to the collectors of the first pair of switching elements Q1 and Q2, and the second terminals of the first pair of voltage divider resistors R5 and R6 are connected to the positive terminals of the first pair of anti-reverse diodes D3 and D4.

[0029] The first terminals of the second pair of voltage divider resistors R7 and R8 are connected to the cathodes of the first pair of anti-reverse diodes D3 and D4, as well as the cathodes of the Zener diodes Z1 and Z2. The second terminals of the second pair of voltage divider resistors R7 and R8 are connected to the anode of the anti-reverse diode D5.

[0030] The positive terminals of the second pair of anti-reverse diodes D1 and D2 are connected to the second terminals of power resistors R3 and R4, and the negative terminals of the second pair of anti-reverse diodes D1 and D2 are connected to the gates of the second pair of switching elements T1 and T2.

[0031] The positive terminal of the anti-reverse diode D5 described in 110 is also connected to the second terminal of the filter capacitor C1, the positive terminals of the Zener diodes Z1 and Z2, and the drain of the second pair of switching elements T1 and T2.

[0032] The gates of the second pair of switching elements T1 and T2 are connected to the positive terminals of Zener diodes Z1 and Z2, respectively, and the source is also connected to the first terminal of a DC brushed motor.

[0033] In some embodiments, the first pair of switching elements Q1 and Q2 are PNP transistors. In some embodiments, the second pair of switching elements T1 and T2 are N-type MOSFETs.

[0034] In any of the foregoing embodiments, the first pair of switching elements can be turned on or off respectively to achieve ground / on signal conversion; the bases of the first pair of switching elements Q1 and Q2 respectively receive the ground / on logic signals of Uin, and the ground / on logic signals received by the bases of Q1 and Q2 are mutually exclusive, that is, the base of Q1 is "ground".

[0035] In the logical state, the base of Q2 is "open circuit," and vice versa; therefore, in the operating state, only one of the first 120 pairs of switching elements Q1 and Q2 is conducting. When the base of Q1 is "grounded," the base of Q2 is "open circuit," Q1 is on, and Q2 is off. At this time, T1 in the second pair of switching elements is off, and T2 is on. The first terminal of the motor is connected to a high voltage through Q1, and the second terminal of the motor is grounded through T2, thus realizing the operation of the motor. The ground / open state of Uin received by the bases of the first pair of switching elements Q1 and Q2 is switched.

[0036] Logic signals can be used to control the forward and reverse rotation of the motor. By changing the 125-second duty cycle of the PWM wave input at the Uin terminal, the motor speed can be controlled.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention.

[0038] It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention 130, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A PWM controlled power conversion circuit for a DC brushed motor, characterized in that, The conversion circuit comprises: current-limiting resistors R1 and R2, a first pair of switching elements Q1 and Q2, power resistors R3 and R4, a first pair of voltage-dividing resistors R5 and R6, a second pair of voltage-dividing resistors R7 and R8, a first pair of anti-reverse diodes D3 and D4, a second pair of anti-reverse diodes D1 and D2, an anti-reverse diode D5, a filter capacitor C1, voltage stabilizing diodes Z1 and Z2, and a second pair of switching elements T1 and T2, wherein the common end of the current-limiting resistors R1 and R2 is connected to the positive pole of a 28V power supply and the first end of the filter capacitor C1, and the second end of the filter capacitor C1 is connected to the base of the first pair of switching elements Q1 and Q2, the first pair of switching elements Q1 and Q2 are connected in series, the emitter of the first pair of switching elements Q1 and Q2 is connected to the positive pole of the 28V power supply, the base of the first pair of switching elements Q1 and Q2 receives a ground / on logic signal, and the ground / on logic signals received by the bases of the first pair of switching elements Q1 and Q2 are mutually exclusive, the first ends of the power resistors R3 and R4 are connected to the first ends of the first pair of voltage-dividing resistors R5 and R6, and the second ends of the power resistors R3 and R4 are connected to the positive poles of the second pair of anti-reverse diodes D1 and D2, the first ends of the first pair of voltage-dividing resistors R5 and R6 are also connected to the collectors of the first pair of switching elements Q1 and Q2, and the second ends of the first pair of voltage-dividing resistors R5 and R6 are connected to the positive poles of the first pair of anti-reverse diodes D3 and D4, the first ends of the second pair of voltage-dividing resistors R7 and R8 are connected to the negative poles of the first pair of anti-reverse diodes D3 and D4 and the negative poles of the voltage stabilizing diodes Z1 and Z2, and the second ends of the second pair of voltage-dividing resistors R7 and R8 are connected to the positive pole of the anti-reverse diode D5, the positive poles of the second pair of anti-reverse diodes D1 and D2 are connected to the second ends of the power resistors R3 and R4, and the negative poles of the second pair of anti-reverse diodes D1 and D2 are connected to the gates of the second pair of switching elements T1 and T2, the positive pole of the anti-reverse diode D5 is also connected to the second end of the filter capacitor C1, the positive poles of the voltage stabilizing diodes Z1 and Z2, and the drains of the second pair of switching elements T1 and T2, the gates of the second pair of switching elements T1 and T2 are connected to the positive poles of the voltage stabilizing diodes Z1 and Z2, respectively, and the sources are also connected to the first end of a DC brush motor.

2. The DC brushed motor PWM control power conversion circuit of claim 1, wherein, The first pair of switching elements Q1 and Q2 are PNP triodes.

3. The DC brushed motor PWM control power conversion circuit of claim 1, wherein, The second pair of switching elements T1 and T2 are N-type MOS tubes.

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