Driver Board

Introduction

A driver board is an electronic module that controls motors and other actuators in CNC, 3D printers, and laser machines. It serves as an interface between the controller (e.g., MKS board) and the high-current devices, allowing precise control of motion without overloading the controller.

Types of Driver Boards

• Stepper Motor Drivers: Control stepper motors using pulse signals; examples include A4988, TMC2208, TMC2130.
• Servo Drivers: Provide PWM signals to control servo motors.
• Laser Drivers: Regulate power to laser modules using PWM or analog signals.
• Motor Shield Boards: Combine multiple drivers with logic circuits for complex systems.

Working Principle

Driver boards receive low-power control signals from the MKS board and convert them into higher-current outputs suitable for motors:

• Microstepping: Divides each full step into smaller increments for smooth motion.
• Current Limiting: Prevents motors from overheating.
• Overvoltage & Thermal Protection: Protects both the board and the motor.
• PWM Control: Adjusts power to modules like lasers or fans precisely.

Main Components

• Control Input Pins: STEP, DIR, EN, PWM, etc.
• Power Stage: MOSFETs or transistors handle high current output.
• Logic Controller: Decodes controller signals into motor-driving sequences.
• Microcontroller/ICs: Implement microstepping, current sensing, and protection features.
• Heat Sink & Cooling: Prevent overheating during prolonged operation.
• Connectors: For motors, power, and controller signals.

Electrical Characteristics

• Input Voltage: Typically 12–24V DC, depending on driver type.
• Current Output: Configurable per motor, often 0.5–2.5A per phase.
• Microstepping Resolution: Full, half, 1/8, 1/16, up to 1/256 steps.
• Protection Features: Overcurrent, thermal shutdown, undervoltage lockout.

Applications

• Controlling stepper motors in CNC, 3D printers, and laser engravers
• Driving servo motors for robotics or precision motion
• Regulating laser modules and fans
• Automation systems requiring precise movement or speed control

Advantages

• Precise control of motor movement
• Microstepping allows smooth motion
• Protects motors from overcurrent and overheating
• Compact and easy to integrate into machines

Limitations

• Requires proper current and voltage configuration
• High microstepping can reduce torque slightly
• Heat dissipation is crucial for prolonged operation
• Not all drivers support all motor types; check compatibility

Connection with MKS Board

Driver boards connect to the MKS board via control pins:

• STEP: Pulse signal for stepping the motor
• DIR: Sets rotation direction
• EN (Enable): Activates or disables the driver output
• Vmot & GND: Power supply inputs for motor operation
• PWM/TTL: Optional for controlling lasers or fans

Correct wiring ensures smooth, precise motion. Drivers should be configured for current limits matching motor specifications.

Maintenance Tips

• Ensure drivers are properly cooled; check heat sinks and airflow.
• Inspect wiring and connectors for loose connections.
• Verify current settings regularly to avoid motor overheating.
• Check for abnormal noises, skipped steps, or overheating as signs of misconfiguration.

Safety Precautions

• Always turn off power before making wiring changes.
• Never exceed rated voltage or current for the driver or motor.
• Keep the board away from conductive surfaces to avoid shorts.
• Ensure proper grounding and ventilation.