A control circuit for a stepper motor

Abstract

The utility model discloses a control circuit of stepping motor, including controller, motor drive chip and inverter, the controller, optional two timer IO mouth all with motor drive chip one group's input and inverter's input electricity is connected, and sends the positive control signal to motor drive chip one group's input and inverter's input, the inverter, its output and motor drive chip another group's input electricity are connected, by input receiving controller's positive control signal from output to motor drive chip sends the reverse control signal, motor drive chip, its two groups of input respectively receive controller's positive control signal and inverter's reverse control signal, by output and stepping motor electricity are connected and can reduce controller IO mouth occupied number, reduce the design cost of enterprise and according to the positive control signal and reverse control signal output drive stepping motor and drive the functional assembly of stage lamp, can.

Description

Technical Field

[0001] This utility model relates to the field of stepper motor circuits, and in particular to a control circuit for a stepper motor. Background Technology

[0002] In today's rapidly evolving stage lighting industry, stage lighting fixtures are mainly divided into two categories: moving head lights and non-moving head lights. One indispensable component in moving head stage lights is the stepper motor. The functional components of moving head stage lights, such as CMY components, pattern components, cutting components, and focus adjustment components, all rely on stepper motors. Therefore, the use of stepper motors in stage lighting is extremely important. With the continuous development of the stage lighting industry, consumers have increasingly higher demands for the functions included in these components. Taking focus adjustment components as an example, consumers have shifted from requiring a single prism, single row of mirrors, and a single fogging plate to requiring double prisms, double row of mirrors, and double fogging plates. The increase in the functionality of functional components means an increase in the number of stepper motors used within them, posing a significant challenge to the motor control circuitry.

[0003] In existing stepper motor control circuits, controlling one stepper motor requires four I / O ports: two timer I / O ports and two general-purpose I / O ports. Due to the increased functionality of stage lighting components, the number of stepper motors required also increases, necessitating an increase in the number of I / O ports for the controller. For example, controlling five stepper motors requires twenty I / O ports, and controlling ten stepper motors requires forty. Furthermore, stepper motors often require magnetic sensors, each of which occupies one I / O port. In addition, other functions also require I / O ports. Therefore, to achieve the desired functionality, controlling five stepper motors requires a 64-pin controller, and controlling ten stepper motors requires a 100-pin controller, resulting in higher design costs. Utility Model Content

[0004] The purpose of this invention is to provide a control circuit for a stepper motor that can reduce the number of controller I / O ports occupied, thereby reducing design costs.

[0005] The control circuit for the stepper motor described in this utility model includes a controller, a motor driver chip, and an inverter.

[0006] The controller can optionally connect two timer I / O ports to the input terminals of one set of motor drive chips and the input terminal of the inverter, and send positive control signals to the input terminals of one set of motor drive chips and the input terminal of the inverter.

[0007] The inverter's output terminal is electrically connected to the input terminal of another group of motor drive chips. The input terminal receives the positive control signal from the controller and sends the reverse control signal to the motor drive chips from the output terminal.

[0008] The motor driver chip has two sets of input terminals that receive the positive control signal from the controller and the reverse control signal from the inverter, respectively. Its output terminal is electrically connected to the stepper motor and outputs a functional component that drives the stepper motor to drive the stage lights according to the positive and reverse control signals.

[0009] In a preferred embodiment of this utility model, the reset / restart pin of the motor drive chip is electrically connected to the control pin of the controller. When the motor drive chip malfunctions, the controller pulls it low to force the motor drive chip to reset and restart.

[0010] As a preferred embodiment of this utility model, the reset / restart pin of the motor drive chip is provided with a current-limiting resistor. One end of the current-limiting resistor is electrically connected to the reset / restart pin of the motor drive chip, and the other end is electrically connected to the control pin of the controller.

[0011] As a preferred embodiment of this utility model, the motor drive chip is provided with an adjustment resistor for adjusting the output current of the motor drive chip. One end of the adjustment resistor is electrically connected to the adjustment pin of the motor drive chip, and the other end is grounded.

[0012] As a preferred embodiment of this utility model, there are two adjustable resistors.

[0013] As a preferred embodiment of this utility model, a relay that dampens the stepper motor is connected to the output terminal of the motor driver chip, and the relay has reserved an open-circuit pin.

[0014] As a preferred embodiment of this utility model, the relay is connected to a resistor that short-circuits one phase of the four-phase power supply at the output of the motor drive chip together.

[0015] The stepper motor control circuit described in this utility model allows for the selection of any two timer I / O ports in the controller. An inverter converts the controller's positive control signal into a negative control signal, which is then transmitted to the motor driver chip. The motor driver chip drives the stepper motor to power the stage light components based on the controller's positive control signal and the inverter's negative control signal. This reduces the number of controller I / O ports required and lowers the company's design costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the control circuit for the stepper motor of this utility model;

[0017] Figure 2 This is the circuit diagram for the controller;

[0018] Figure 3 A schematic diagram of the controller's timer I / O ports;

[0019] Figure 4 This is the circuit diagram for an inverter;

[0020] Figure 5 This is the circuit diagram of the motor driver chip;

[0021] Figure 6 This is the circuit diagram for a relay. Detailed Implementation

[0022] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] This embodiment provides a control circuit for a stepper motor, such as... Figure 1 As shown, the system includes a controller (MCU), a motor driver chip (IC1), and an inverter (IC2). The controller has two timer I / O ports that are electrically connected to one set of inputs of the motor driver chip and the inverter, respectively, and sends positive control signals to both inputs. The inverter's output is electrically connected to the other set of inputs of the motor driver chip, receiving the positive control signal from the controller and sending a reverse control signal to the motor driver chip from its output. The motor driver chip has two sets of inputs that receive the positive control signal from the controller and the reverse control signal from the inverter, respectively. Its output is electrically connected to a stepper motor and outputs a functional component that drives the stepper motor to power the stage lights, based on the positive and reverse control signals.

[0024] like Figure 2 As shown, in this embodiment, the controller MCU selected is an STM32G474RBT3 controller MCU, which has twenty-eight timer I / O ports, as shown in the figure. Figure 3 As shown, taking the control of a stepper motor as an example, two PC0 and PC3 pins can be selected from the twenty-eight timer I / O ports. The PC0 pin is labeled U2-B2, and the PC3 pin is labeled U2-A2. The controller MCU is electrically connected to the motor driver chip IC1 and the inverter IC2 through the PC0 pin U2-B2 and the PC3 pin U2-A2. The PB2 control pin of the controller MCU, Motorreset, is electrically connected to the reset / restart pin of the motor driver chip IC1.

[0025] like Figure 4As shown, the 1IN pin U2-A2 and 2IN pin U2-B2 of inverter IC2 serve as the input terminals of inverter IC2 and are electrically connected to the controller MCU via the PC0 pin U2-B2 and PC3 pin U2-A2. The 1OUT pin U2-A1 and 2OUT pin U2-B1 of inverter IC2 serve as the output terminals of inverter IC2 and are electrically connected to one set of input terminals of motor driver chip IC1. The 1IN pin U2-A2 and 2IN pin U2-B2 of inverter IC2 receive the positive control signal sent by the controller MCU via the PC0 pin U2-B2 and PC3 pin U2-A2, and send the reverse control signal from the output pins 1OUT pin U2-A1 and 2OUT pin U2-B1 to one set of input terminals of motor driver chip IC1. In this embodiment, inverter IC2 is a 74LVC2G14 inverter.

[0026] like Figure 5 As shown, in this embodiment, the motor driver chip IC1 is an SS8841 model. Pins BIN2 (U2-A2) and AIN2 (U2-B2) of the motor driver chip IC1 are connected as one set of input terminals to pins PC0 (U2-B2) and PC3 (U2-A2) of the controller MCU to receive the positive control signal from the controller MCU. Pins BIN1 (U2-A1) and AIN1 (U2-B1) of the motor driver chip IC1 are connected as the other set of input terminals to pins 1OUT (U2-A1) and 2OUT (U2-B1) of the inverter IC2 to receive the inverted control signal from the inverter IC2. Pins AOUT1 (M7-A1), AOUT2 (M7-A2), BOUT1 (M7-B1), and BOUT2 (M7-B2) of the motor driver chip IC1 are connected as output terminals to the stepper motor, thereby controlling the stepper motor and driving the functional components of the stage lights. This reduces the number of controller I / O ports required, significantly reducing the enterprise's design costs.

[0027] The nRESET reset pin of the motor driver chip IC1 is electrically connected to the PB2 control pin of the controller MCU via a current-limiting resistor R6, which has a resistance of 4K 7Ω. When the motor driver chip IC1 malfunctions, the controller MCU can force a reset and restart by pulling the PB2 control pin (Motor reset) low, preventing the motor driver chip IC1 from operating in an abnormal state for an extended period, thus avoiding permanent internal damage.

[0028] The motor driver chip IC1 includes adjustable resistors to regulate the output current. One end of each resistor is electrically connected to the adjustment pin of the motor driver chip, and the other end is grounded. There are two adjustable resistors, R22 and R23. One end of R22 is connected to the ISENA pin of the motor driver chip IC1, and the other end is grounded. One end of R23 is connected to the ISENB pin of the motor driver chip IC1, and the other end is grounded. Both resistors R22 and R23 can have a resistance value of 0.33R, in which case the output current of the motor driver chip IC1 is 1.52A. By selecting different resistor values, the maximum output current of the motor driver chip IC1 can reach 2.5A, which is sufficient to power a stepper motor-driven stage light component.

[0029] A relay K1, which acts as a damper for the stepper motor, is connected to the output of the motor driver chip. Figure 6 As shown, pin 6 (M7-A1) of relay K1 is electrically connected to pin AOUT1 (M7-A1) of motor driver chip IC1; pin 7 (M7-A2) of relay K1 is electrically connected to pin AOUT2 (M7-A2) of motor driver chip IC1; pin 2 (M7-B1) of relay K1 is electrically connected to pin BOUT1 (M7-B1) of motor driver chip IC1; and pin 3 (M7-B2) of relay K1 is electrically connected to pin BOUT2 (M7-B2) of motor driver chip IC1. Pins 4 and 5 of relay K1 are open-circuit pins. Pins 3 and 6 of relay K1 contain bidirectional switches. When the stage lights are powered, the bidirectional switch on pin 3 engages with pin 4, and the bidirectional switch on pin 6 engages with pin 5. Since pins 4 and 5 of relay K1 are open-circuit pins, they do not affect the normal operation of the stepper motor. When the stage lighting loses power, the bidirectional switch on pin 3 of relay K1 engages with pin 2, and the bidirectional switch on pin 6 of relay K1 engages with pin 7. This effectively short-circuits all four phases (A, B, C, and D) of the stepper motor, increasing the internal resistance of the stepper motor's coils and creating significant resistance during rotation. This prevents damage to the components caused by the sudden power outage. It also ensures the stability of the components during transport, preventing damage from vibrations.

[0030] The relay is connected to a resistor RJ1 that short-circuits one phase of the four-phase power output of the motor driver chip. When the stepper motor used is a three-phase motor, one end of the resistor RJ1 can be electrically connected to pin 7 M7-A2 of the relay K1, and the other end of the resistor RJ1 can be electrically connected to pin 2 M7-B1 of the relay K1 to achieve the effect of adapting to stepper motors with different phase power.

[0031] The above embodiments are only used to illustrate the detailed solution of this utility model. This utility model is not limited to the above detailed solution, that is, it does not mean that this utility model must rely on the above detailed solution to be implemented. Those skilled in the art should understand that any improvement to this utility model, equivalent substitution of the raw materials of this utility model product, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this utility model.

Claims

1. A control circuit for a stepper motor, characterized in that, This includes the controller MCU, the motor drive chip IC1, and the inverter IC2; The controller can arbitrarily connect two of its timer I / O ports to the input terminals of one set of motor drive chips and the input terminal of the inverter, and send positive control signals to the input terminals of one set of motor drive chips and the input terminal of the inverter. The inverter's output terminal is electrically connected to the input terminal of another group of motor drive chips. The input terminal receives the positive control signal from the controller and sends the reverse control signal to the motor drive chips from the output terminal. The motor driver chip has two sets of input terminals that receive the positive control signal from the controller and the reverse control signal from the inverter, respectively. Its output terminal is electrically connected to the stepper motor and outputs a functional component that drives the stepper motor to drive the stage lights according to the positive and reverse control signals.

2. The control circuit for the stepper motor according to claim 1, characterized in that, The reset / restart pin of the motor drive chip is electrically connected to the control pin of the controller. When the motor drive chip malfunctions, the controller pulls it low to force the motor drive chip to reset and restart.

3. The control circuit for the stepper motor according to claim 2, characterized in that, The reset / restart pin of the motor drive chip is equipped with a current-limiting resistor R6. One end of the current-limiting resistor is electrically connected to the reset / restart pin of the motor drive chip, and the other end is electrically connected to the control pin of the controller.

4. The control circuit for the stepper motor according to claim 1, characterized in that, The motor driver chip is equipped with an adjustment resistor to regulate the output current of the motor driver chip. One end of the adjustment resistor is electrically connected to the adjustment pin of the motor driver chip, and the other end is grounded.

5. The control circuit for the stepper motor according to claim 4, characterized in that, There are two adjustable resistor settings.

6. The control circuit for the stepper motor according to any one of claims 1-5, characterized in that, A relay K1, which acts as a damper for the stepper motor, is connected to the output of the motor driver chip. The relay has an open-circuit pin.

7. The control circuit for the stepper motor according to claim 6, characterized in that, The relay is connected to a resistor RJ1 that short-circuits one phase of the four-phase power supply at the output of the motor drive chip.

Images