Stepping motor drive circuit and control method thereof

Abstract

The invention discloses a stepping motor drive circuit and a control method thereof. The circuit is characterized in that: a power supply signal input filtering protection circuit, a motor current detection circuit and a key scan circuit are connected to a control chip simultaneously, and the control chip sends a control signal to a motor drive chip; an inner and outer circulation motor, a mixed air door motor and a mode motor share four phase lines and are connected to the motor drive chip, and the inner and outer circulation motor, the mixed air door motor and the mode motor are connected to the motor drive chip through an independent motor power line respectively. Since the above circuit structure is employed, the drive circuit has the following advantages: (1) occupation of PCB space is small, and a purpose of increasing space capacity in a vehicle is realized; (2) the motor phase lines are shared, number of wire harness is reduced, and external wiring is simple; (3) a stepping motor is prevented from appearance of phenomena of loss of synchronism, super-step and locked rotor; and (4) only one motor drive chip is used, and production cost is reduced.

Description

[0001] Involved [0002] The invention relates to the field of automobile air-conditioning control, in particular to a stepping motor drive circuit and control method. Background technique [0003] With the miniaturization of modern cars, the enlargement of the interior space, and the requirements of the body's own weight and energy saving, the stepper motor drive circuit used in the car air conditioner is increasingly unable to meet the requirements of on-board equipment. [0004] At present, the stepping motor drive circuit in the car air conditioner controller is controlled by a dedicated chip, but it is expensive and the wiring harness from the motor control circuit to the motor end is many and long, which takes up a lot of PCB space, causing the control panel to occupy a large space in the car . [0005] In addition, stepper motors often lose steps and oversteps during use. This is because the excitation changes fast but the mechanical position of the stepper motor cannot keep up...

AI Technical Summary

Problems solved by technology

[0003] With the miniaturization of modern cars, the enlargement of the interior space, and the requirements of the weight of the car body and energy saving, the stepper motor drive circuit used in the car air conditioner is increasingly unable to meet the requirements of the car equipment.

[0004] At present, the driving circuit of the stepping motor in the car air conditioner controller is controlled by a dedicated chip, but it is expensive and the wiring harness from the motor control circuit to the motor end is long and long, which takes up a lot of space on the PCB, causing the control panel to take up a lot of space in the car

[0005] And stepper motors often lose steps and overstep during use. This is because the excitation changes rapidly but the mechanical position of the stepper motor cannot keep up. If the excitation frequency is not selected properly, the motor cannot move to a new position. There is a permanent error between the actual load position and the target position, that is, out-of-step phenomenon occurs; or if the motor stops suddenly at the maximum excitation frequency when stopping, the motor exceeds the target position due to inertia, resulting in overstepping phenomenon

[0006] To provide a new type of stepper motor drive circuit and control method, to drive the stepper motor with smaller size and lower cost, and to prevent the phenomenon of stepping out, overstepping and stalling of the stepping motor. Problems that technology needs to solve

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