Coordination circuit and drive circuit for driving bipolar stepper motor

Abstract

The present invention relates to a matching circuit and a driving circuit for driving a bipolar stepping motor, comprising four transistors Q1, Q2, Q3 and Q4, four resistors R1, R2, R3 and R4, and four terminals AOUT1, AOUT2, BOUT1 and BOUT2 for connecting to lead wires of the bipolar stepping motor; the base of the transistor Q1 is connected to one end of the resistor R1, and the other end of the resistor R1 and the collector of the transistor Q2 are connected to the terminal AOUT2; the base of the transistor Q2 is connected to one end of the resistor R2, and the other end of the resistor R2 and the collector of the transistor Q1 are connected to the terminal AOUT1; the base of the transistor Q3 is connected to one end of the resistor R3, and the other end of the resistor R3 and the collector of the transistor Q4 are connected to the terminal BOUT2; the base of the transistor Q4 is connected to one end of the resistor R4, and the other end of the resistor R4 and the collector of the transistor Q3 are connected to the terminal BOUT1. The present invention can utilize a unipolar stepping motor driver to drive a bipolar stepping motor, thereby greatly reducing the difficulty of change.

Description

Technical Field

[0001] The present invention relates to a stepping motor driving circuit, and in particular to a matching circuit and a driving circuit for driving a bipolar stepping motor. Background Art

[0002] The drive control of a bipolar stepper motor generally requires a bipolar stepper motor dedicated driver to connect to the Darlington transistor. The Darlington transistor receives input signals from a programmable device such as an MCU, inputs level pulses to the bipolar stepper motor dedicated driver, and then the bipolar stepper motor dedicated driver outputs voltage to control the bipolar stepper motor. For specific connections, please refer to the attached Figure 1 The drive of unipolar stepper motor is relatively simple, and it can be directly connected to the unipolar stepper motor through Darlington tube. For details, please refer to the attached Figure 2 .

[0003] There are numerous devices on the market that use unipolar stepper motor drivers to control unipolar stepper motors. However, unipolar motors generally have low torque and speed. With technological advancements, improvements to these devices are needed. A common requirement is to replace unipolar stepper motors with bipolar stepper motors, which can increase both torque and speed. However, upgrading bipolar stepper motors requires a dedicated bipolar stepper motor driver. Furthermore, because unipolar stepper motor drivers are typically integrated onto the customer's motherboard, modifying them is difficult and increases costs. Summary of the Invention

[0004] The first purpose of the present invention is to provide a matching circuit for driving a bipolar stepper motor, so that a driving board that has integrated a unipolar stepper motor driver can be directly used to drive a bipolar stepper motor through simple modification, greatly reducing the difficulty of modification and reducing the modification cost.

[0005] The technical solution for achieving the first object of the present invention is as follows: the matching circuit for driving a bipolar stepping motor of the present invention includes four transistors Q1, Q2, Q3 and Q4, four resistors R1, R2, R3 and R4, and four terminals AOUT1, AOUT2, BOUT1 and BOUT2 for connecting to lead wires of the bipolar stepping motor; the base of the transistor Q1 is connected to one end of the resistor R1, and the other end of the resistor R1 and the collector of the transistor Q2 are connected to the terminal AOUT2; the base of the transistor Q2 is connected to one end of the resistor R2, and the other end of the resistor R2 and the collector of the transistor Q1 are connected to the terminal AOUT1;

[0006] The base of transistor Q3 is connected to one end of resistor R3, and the other end of resistor R3 and the collector of transistor Q4 are connected to terminal BOUT2; the base of transistor Q4 is connected to one end of resistor R4, and the other end of resistor R4 and the collector of transistor Q3 are connected to terminal BOUT1.

[0007] Furthermore, a diode D1 is connected in series to the connection line between the resistor R1 and the terminal AOUT2; a diode D2 is connected in series to the connection line between the resistor R2 and the terminal AOUT1; a diode D3 is connected in series to the connection line between the resistor R3 and the terminal BOUT2; and a diode D4 is connected in series to the connection line between the resistor R4 and the terminal BOUT1.

[0008] Furthermore, the transistors Q1, Q2, Q3 and Q4 are all SOT-23 type.

[0009] A second object of the present invention is to provide a driving circuit for driving a bipolar stepping motor.

[0010] The technical solution for achieving the second object of the present invention is: the driving circuit for driving a bipolar stepping motor in the present invention includes a Darlington transistor for driving a unipolar stepping motor, the above-mentioned matching circuit for driving a bipolar stepping motor, and a bipolar stepping motor;

[0011] Pins 1C, 2C, 3C, and 4C of the Darlington transistor are connected to terminals AOUT1, AOUT2, BOUT1, and BOUT2, respectively; the common terminal of the clamping diode of the Darlington transistor is connected to the emitter of the transistor Q1;

[0012] The connection terminals AOUT1, AOUT2, BOUT1 and BOUT2 are connected to the lead wires of the bipolar stepping motor.

[0013] Furthermore, the model of the Darlington tube is ULN2003A.

[0014] The present invention has positive effects: (1) Without changing the original unipolar stepper motor control circuit, the present invention only needs to add a matching circuit to directly drive a bipolar stepper motor, which greatly reduces the difficulty of transformation and reduces the transformation cost.

[0015] (2) The present invention is based on a coordinated circuit. Compared with the traditional H-bridge upper and lower bridge control scheme, there is no risk of short-circuiting the circuit. This is also the key to directly driving a bipolar stepper motor through the coordinated circuit.

[0016] (3) The circuit of the present invention utilizes four transistors Q1, Q2, Q3, and Q4 to make the VBE conduction voltage very low (typically 0.5V, much lower than the MOS tube conduction voltage), thereby enabling the circuit to operate at a very low voltage.

[0017] (4) The four resistors R1, R2, R3, and R4 in the present invention are current-limiting resistors, which reduce the risk of burning of the transistor.

[0018] (5) Since the transistor will have a certain voltage drop under high current conditions, the present invention uses four diodes D1, D2, D3, and D4 to ensure that the circuit operates normally when the voltage drop is no greater than the forward voltage drop of the diode (about 0.7V). BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein

[0020] Figure 1 A driving circuit for an existing bipolar stepping motor;

[0021] Figure 2 A driving circuit for an existing unipolar stepping motor;

[0022] Figure 3 A matching circuit for driving a bipolar stepping motor in the present invention;

[0023] Figure 4 This is a driving circuit for driving a bipolar stepping motor in the present invention. DETAILED DESCRIPTION

[0024] See Figure 3 The coordinated circuit for driving a bipolar stepping motor of the present invention includes four transistors Q1, Q2, Q3, and Q4, four diodes D1, D2, D3, and D4, four resistors R1, R2, R3, and R4, and four terminals AOUT1, AOUT2, BOUT1, and BOUT2 for connecting to lead wires of the bipolar stepping motor; the base of the transistor Q1 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the collector of the transistor Q2 at the terminal AOUT2; the base of the transistor Q2 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the collector of the transistor Q1 at the terminal AOUT1;

[0025] The base of transistor Q1 is connected to one end of resistor R1, the other end of resistor R1 is connected to the anode of diode D1, and the cathode of diode D1 and the collector of transistor Q2 are connected to terminal AOUT2. The base of transistor Q2 is connected to one end of resistor R2, the other end of resistor R2 is connected to the anode of diode D2, and the cathode of diode D2 and the collector of transistor Q1 are connected to terminal AOUT1.

[0026] The base of transistor Q3 is connected to one end of resistor R3, the other end of resistor R3 is connected to the anode of diode D3, and the cathode of diode D3 and the collector of transistor Q4 are connected to terminal BOUT2; the base of transistor Q4 is connected to one end of resistor R4, the other end of resistor R4 is connected to the anode of diode D4, and the cathode of diode D4 and the collector of transistor Q3 are connected to terminal BOUT1.

[0027] The transistors Q1, Q2, Q3 and Q4 are all SOT-23 type.

[0028] See Figure 4 The driving circuit for driving a bipolar stepping motor of the present invention includes a Darlington transistor for driving a unipolar stepping motor, the above-mentioned matching circuit for driving a bipolar stepping motor, and a bipolar stepping motor;

[0029] Pins 1C, 2C, 3C, and 4C of the Darlington transistor are connected to terminals AOUT1, AOUT2, BOUT1, and BOUT2, respectively; the common terminal of the clamping diode of the Darlington transistor is connected to the emitter of the transistor Q1;

[0030] The connection terminals AOUT1, AOUT2, BOUT1 and BOUT2 are connected to the lead wires of the bipolar stepping motor.

[0031] Pins 1C, 2C, 3C, and 4C correspond to Figure 4 The pin numbers in the pinout are 16, 15, 14, and 13; the common terminal of the clamping diode of the Darlington tube corresponds to Figure 4 Pin number 9 in .

[0032] The model of the Darlington tube is ULN2003A.

[0033] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A matching circuit for driving a bipolar stepping motor, characterized in that: The device includes four transistors Q1, Q2, Q3, and Q4, four resistors R1, R2, R3, and R4, and four terminals AOUT1, AOUT2, BOUT1, and BOUT2 for connecting to lead wires of a bipolar stepping motor; the base of the transistor Q1 is connected to one end of the resistor R1, and the other end of the resistor R1 and the collector of the transistor Q2 are connected to the terminal AOUT2; the base of the transistor Q2 is connected to one end of the resistor R2, and the other end of the resistor R2 and the collector of the transistor Q1 are connected to the terminal AOUT1; The base of transistor Q3 is connected to one end of resistor R3, and the other end of resistor R3 and the collector of transistor Q4 are connected to terminal BOUT2. The base of transistor Q4 is connected to one end of resistor R4, and the other end of resistor R4 and the collector of transistor Q3 are connected to terminal BOUT1. It also includes a Darlington transistor for driving a unipolar stepper motor; pins 1C, 2C, 3C, and 4C of the Darlington transistor are connected to terminals AOUT1, AOUT2, BOUT1, and BOUT2 respectively; and a common end of the clamping diode of the Darlington transistor is connected to the emitter of the transistor Q1.

2. The coordinated circuit for driving a bipolar stepping motor according to claim 1, characterized in that: A diode D1 is connected in series to the connection line between the resistor R1 and the terminal AOUT2; a diode D2 is connected in series to the connection line between the resistor R2 and the terminal AOUT1; a diode D3 is connected in series to the connection line between the resistor R3 and the terminal BOUT2; and a diode D4 is connected in series to the connection line between the resistor R4 and the terminal BOUT1.

3. The coordinated circuit for driving a bipolar stepping motor according to claim 1, characterized in that: The transistors Q1, Q2, Q3 and Q4 are all SOT-23 type.

4. A driving circuit for driving a bipolar stepping motor, characterized in that: Comprising the matching circuit for driving a bipolar stepping motor and the bipolar stepping motor according to claim 1, 2 or 3; The connection terminals AOUT1, AOUT2, BOUT1 and BOUT2 are connected to the lead wires of the bipolar stepping motor.

5. The driving circuit for driving a bipolar stepping motor according to claim 4, characterized in that: The model of the Darlington tube is ULN2003A.

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