April 01, 2014

DC SERVO DRIVER

There are a lot of motor types that were intergrated in many devices, robots, automatic systems….DC motor is very popular actual with better characties than the other motors.

The project used MCU PIC18F4620, TI LM629-N and single channel H-Bridge to control directly a position round of DC motor

The LM628/LM629 are dedicated motion-control processors designed for use with a variety of DC and brushless DC servo motors, and other servomechanisms which provide a quadrature incremental position feedback signal. The parts perform the intensive, real-time computational tasks required for high performance digital motion control. The host control software interface is facilitated by a high-level command set. The LM628 has an 8-bit output which can drive either an 8-bit or a 12-bit DAC. The components required to build a servo system are reduced to the DC motor/actuator, an incremental encoder, a DAC, a power amplifier, and the LM628. An LM629-based system is similar, except that it provides an 8-bit PWM output for directly driving H-switches.

User set the parameters (trajectory, velocity, aceleration…) then click RUN command to the mainboard. In process of running, driver will send feedback signals that were drawn on chart to show user can follow and control.

 Full view

 Power Regulator, MCU, LM629, Shift data IC, USB interface, Crystals, Isolators……….

 Top view

 DC motor and 334 x 4 pulse Encoder

 Control Center

 H-Bridge with Heat-sink cooler

 Tittle

 MiniUSB connector, Main supply(left-side jack) and Power supply(right-side jack)

 Motor is running

Process Complete

Base on respoding of motor's signal on diagram, We also can calculate to find other parameters like rising time, max torque, max round, available PID parameters by tuning the servo.