Motor driving circuit without program control

Abstract

The utility model discloses a motor driving circuit without program control, comprising a driving module which is connected with a motor and provides driving for the motor; the control module comprises an RC feedback loop, the RC feedback loop is connected with the power supply and the driving module, the RC feedback loop introduces feedback from the output end of the driving module or the motor, the RC feedback loop outputs a control signal to the driving module under the combined action of the power supply and the feedback, and the control signal controls the driving module to drive the motor when the motor is powered on for the first time and runs normally. And after the motor stalls, the control signal controls the driving module to turn off the driving. The motor drive circuit is a pure circuit without programming, the triodes, the NMOS tubes and the RC circuit are used in the circuit, the circuit can detect locked-rotor current and be automatically turned off, the product and labor cost can be effectively reduced, the design period is shortened, and the product quality stability is improved.

Description

Technical Field

[0001] The utility model relates to a motor drive circuit without program control. Background Art

[0002] As the automotive market matures, automakers are tightening their control over product costs and R&D cycles. Existing motor stall shutdown designs rely on a "full-bridge + control chip" approach. This design requires numerous components, resulting in high costs. Furthermore, it requires an MCU and software support, resulting in high design costs and a long development cycle. Utility Model Content

[0003] The utility model provides a motor drive circuit without program control, which can detect the stall current and automatically shut down, can effectively simplify the number of components and reduce costs, and does not require software support, has low design labor costs, and can effectively shorten the design cycle.

[0004] According to one aspect of the embodiment, a motor drive circuit without program control is provided, comprising: a drive module connected to a motor to provide drive to the motor; and a control module including an RC feedback loop, the RC feedback loop being connected to a power supply and the drive module, the RC feedback loop introducing feedback from an output end of the drive module or the motor, the RC feedback loop utilizing the power supply and feedback to output a control signal to the drive module, the control signal controlling the drive module to drive the motor when power is first applied and when the motor is operating normally, and the control signal controlling the drive module to shut down the drive after the motor is stalled.

[0005] In some examples, the control signal is a level signal. When power is first applied and the motor is operating normally, the RC feedback loop utilizes the power supply and feedback to output a high-level signal to control the drive module to drive the motor. After the motor stalls, the RC feedback loop utilizes the power supply and feedback to output a low-level signal to control the drive module to shut down the drive.

[0006] In some examples, the driving module includes an NMOS transistor U1A and an NMOS transistor U1B, and the positive electrode of the power supply, the NMOS transistor U1A, the motor, the NMOS transistor U1B, and the negative electrode of the power supply are connected in sequence.

[0007] In some examples, the RC feedback loop includes a first RC feedback loop for controlling the NMOS transistor U1A and a second RC feedback loop for controlling the NMOS transistor U1B.

[0008] In some examples, the gate of the NMOS tube U1A is connected to the output of the first RC feedback loop, the source is connected to the positive terminal of the power supply, and the drain is connected to the power terminal of the motor through the first sampling resistor as the output of the driving module. A resistor R4 and a Zener diode ZD1 are connected in parallel between the gate and the source.

[0009] In some examples, the gate of the NMOS tube U1B is connected to the output of the second RC feedback loop, the source is connected to the negative electrode of the power supply, and the drain is connected to another power terminal of the motor through the second sampling resistor as the output of the drive module. A resistor R5 and a Zener diode ZD2 are connected in parallel between the gate and the source.

[0010] In some examples, the first RC feedback loop includes a transistor Q1, a resistor R6, a capacitor C1, and a capacitor C2. The emitter of the transistor Q1 is connected to the positive terminal of the power supply, the capacitor C1 is connected between the base and the emitter, and the collector is connected to the gate of the NMOS tube U1A as the output of the first RC feedback loop. One end of the resistor R6 is connected to the output terminal of the drive module or the motor introduces feedback, and the other end of the resistor R6 is connected to the base of the transistor Q1 and one end of the capacitor C2. The other end of the capacitor C2 is connected to the positive terminal of the power supply.

[0011] In some examples, the second RC feedback loop includes a transistor Q2, a resistor R15, a capacitor C4, and a capacitor C5. The emitter of the transistor Q2 is connected to the negative pole of the power supply, the capacitor C4 is connected between the base and the emitter, and the collector is connected to the gate of the NMOS tube U1B as the output of the second RC feedback loop. The collector of the transistor Q1 is connected to the collector of the transistor Q2 through the resistor R8. One end of the resistor R15 is connected to the output end of the drive module or the motor introduces feedback. The other end of the resistor R15 is connected to the base of the transistor Q2 and one end of the capacitor C5. The other end of the capacitor C5 is connected to the negative pole of the power supply.

[0012] In some examples, the collector of transistor Q1 is connected to the collector of transistor Q2 via resistor R8 . BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of a motor drive circuit according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0014] The term "connected" should be understood to include direct connection and indirect connection through one or more intermediate devices. The motor drive circuit of the present invention can be applied to, but not limited to, automotive rearview mirror folding actuators, sunroof actuators, electric door and window actuators, and wiper motor actuators.

[0015] like Figure 1As shown, the motor drive circuit includes a control module 1 and a drive module 2. The input end of the drive module 2 is connected to the output end of the control module 1, receives the control signal and takes corresponding actions. The input end of the motor 3 is connected to the output end of the drive module 2, receives the drive current and takes corresponding actions. The control module 1 is connected to the power supply and introduces feedback from the output end of the drive module 2. The power supply and feedback work together to output a control signal to the drive module 2. That is, when the power is first turned on, a high-level signal is output to control the drive module 2 to drive the motor 3. After the motor 3 is stalled, a low-level signal is output to control the drive module 2 to shut down the drive.

[0016] The control module 1 includes two RC feedback circuits. This embodiment uses NPN transistors as an example for description, but other types of transistors are also feasible.

[0017] The emitter of transistor Q1 is connected to the positive power supply terminal IN+, with capacitor C1 connected between the base and emitter. One end of resistor R6 serves as the input of control module 1, introducing feedback from driver module 2. The other end of resistor R6 is connected to the base of Q1 and one end of capacitor C2, and the other end of capacitor C2 is connected to the positive power supply terminal IN+. Resistor R6, capacitor C1, capacitor C2, and transistor Q1 form the first RC feedback loop.

[0018] The emitter of transistor Q2 is connected to the negative power supply terminal IN-. Capacitor C4 is connected between the base and emitter. One end of resistor R15 serves as the input of control module 1, introducing feedback from driver module 2. The other end of resistor R15 is connected to the base of Q2 and one end of capacitor C5. The other end of capacitor C5 is connected to the negative power supply terminal IN-. Resistor R15, capacitor C4, capacitor C5, and transistor Q2 form a second RC feedback loop.

[0019] The collectors of transistor Q1 and transistor Q2 are connected, and a resistor R8 is provided on the connection line.

[0020] The driving module 2 includes NMOS transistors U1A and U1B. Of course, other types of MOS transistors are also feasible.

[0021] The gate of NMOS transistor U1A is connected to the collector of transistor Q1, the source is connected to the positive power supply IN+, and the drain is connected to the motor through a first sampling resistor. Resistor R4 and Zener diode ZD1 are connected in parallel between the gate and source. The first sampling resistor can be three parallel resistors R1, R2, and R3.

[0022] The gate of NMOS transistor U1B is connected to the collector of transistor Q2, the source is connected to the negative power supply IN-, and the drain is connected to the motor through a second sampling resistor. Resistor R5 and Zener diode ZD2 are connected in parallel between the gate and source. The second sampling resistor can be three parallel resistors R10, R11, and R12.

[0023] Capacitor C3 and resistor R9 are connected in parallel between the input and output of the motor.

[0024] During the initial power-up, transistors Q1 and Q2 cannot conduct due to the delay effect of the RC circuit. The gate voltage of the NMOS transistor in driver module 2 is provided by the power supply and the voltage divider circuit, allowing the NMOS transistor to conduct. For example, with IN+ connected to the positive power supply and IN- connected to the negative power supply, a drive loop of "positive power supply - NMOS (U1A) - motor 3 - NMOS (U1B) - negative power supply" is formed. The corresponding RC feedback loop is short-circuited, and the input voltage is approximately the voltage across the sampling resistor (IRR). The input current flowing through the base resistors R6 and R15 (collectively referred to as RB) of transistors Q1 and Q2 is (IRR / RB). At this point, the input current is too small to turn on the transistors.

[0025] When the motor is stalled, the current flowing through the "positive pole of power supply - NMOS (U1A) - motor 3 - NMOS (U1B) - negative pole of power supply" drive circuit increases, the voltage across the sampling resistor (IRR) increases, and the input current (IRR / RB) flowing through the base resistor RB increases. After the RC circuit delays and a period of stalling, the input current increases to the point where the transistor can be turned on. The gate voltage of the NMOS of the driver module 2 is pulled down, and the driver module turns off the output, forming a "positive pole of power supply - NMOS (U1A) - motor 3 - RC feedback circuit - negative pole of power supply" conduction loop. At this time, the transistor will remain continuously turned on, and the driver module cannot be turned on again until the next power cycle.

Claims

1. A motor drive circuit without program control, characterized in that: include: A drive module connected to the motor to provide drive to the motor; as well as The control module includes an RC feedback loop, which is connected to the power supply and the drive module. The RC feedback loop introduces feedback from the output end of the drive module or the motor. The RC feedback loop uses the power supply and feedback to output a control signal to the drive module. When the power is first turned on and the motor is running normally, the control signal controls the drive module to drive the motor. After the motor is stalled, the control signal controls the drive module to shut down the drive.

2. The motor drive circuit without program control according to claim 1, characterized in that: The control signal is a level signal. When the power is first turned on and the motor is running normally, the RC feedback loop uses the power supply and feedback to output a high-level signal to control the drive module to drive the motor. After the motor is stalled, the RC feedback loop uses the power supply and feedback to output a low-level signal to control the drive module to shut down the drive.

3. The motor drive circuit without program control according to claim 1 or 2, characterized in that: The driving module includes an NMOS tube U1A and an NMOS tube U1B. The positive pole of the power supply, the NMOS tube U1A, the motor, the NMOS tube U1B and the negative pole of the power supply are connected in sequence.

4. The motor drive circuit without program control according to claim 3, characterized in that: The RC feedback loop includes a first RC feedback loop for controlling the NMOS transistor U1A and a second RC feedback loop for controlling the NMOS transistor U1B.

5. The motor drive circuit without program control according to claim 4, characterized in that: The gate of the NMOS tube U1A is connected to the output of the first RC feedback loop, the source is connected to the positive terminal of the power supply, and the drain, as the output of the drive module, is connected to the power supply terminal of the motor through the first sampling resistor. A resistor R4 and a voltage regulator diode ZD1 are connected in parallel between the gate and the source.

6. The motor drive circuit without program control according to claim 5, characterized in that: The gate of the NMOS tube U1B is connected to the output of the second RC feedback loop, the source is connected to the negative electrode of the power supply, and the drain, as the output of the drive module, is connected to the other power terminal of the motor through the second sampling resistor. A resistor R5 and a Zener diode ZD2 are connected in parallel between the gate and source.

7. The motor drive circuit without program control according to claim 6, characterized in that: The first RC feedback loop includes a transistor Q1, a resistor R6, a capacitor C1, and a capacitor C2. The emitter of the transistor Q1 is connected to the positive terminal of the power supply, the capacitor C1 is connected between the base and the emitter, and the collector is connected to the gate of the NMOS tube U1A as the output of the first RC feedback loop. One end of the resistor R6 is connected to the output end of the drive module or the motor introduces feedback, and the other end of the resistor R6 is connected to the base of the transistor Q1 and one end of the capacitor C2. The other end of the capacitor C2 is connected to the positive terminal of the power supply.

8. The motor drive circuit without program control according to claim 7, characterized in that: The second RC feedback loop includes transistor Q2, resistor R15, capacitor C4 and capacitor C5. The emitter of transistor Q2 is connected to the negative electrode of the power supply, capacitor C4 is connected between the base and emitter, and the collector is connected to the gate of NMOS tube U1B as the output of the second RC feedback loop. The collector of transistor Q1 is connected to the collector of transistor Q2 through resistor R8. One end of resistor R15 is connected to the output end of the drive module or the motor introduces feedback, and the other end of resistor R15 is connected to the base of transistor Q2 and one end of capacitor C5. The other end of capacitor C5 is connected to the negative electrode of the power supply.

9. The motor driving circuit without program control according to claim 8, characterized in that: The collector of the transistor Q1 is connected to the collector of the transistor Q2 via the resistor R8.

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