7425AC Copley Controls Corp Brushless Servo Amplifier

The Copley Controls Corp 7225AC and 7425AC models are PWM servoamplifiers for AC brushless servomotors that are commutated externally by digital control systems that output two +/-10V signals that represent the current command to the motor U and V windings. The amplifier then synthesizes the current command for the W winding.

Control cards take feedback from an encoder on the motor and use various techniques to determine the rotor position. Then the controller is able to output two signals that correspond to the current in the U and V windings to produce torque in the motor. The amplifier synthesizes the W winding current from UV signals that are either 120 or 90 electrical degrees apart.

Amplifier adjustments with this system consist of inductance compensation, current limit, transconductance, and offset. Thereafter, the controller does all of the velocity and/or position control of the motor.

An internal 40-pin solderless socket lets the user configure the various gain and current limit settings to customize the amplifiers for a wide range of loads and applications. Header components permit compensation over a wide range of load inductance's to maximize bandwidth with different motors.

Current limiting is provided via an internal solderless header socket or by an external resistance or voltage applied to the signal connector. The /Enable input active logic-level is switch-selectable to ground or +5V to interface with all types of control cards. Fail-safe operation in either polarity results from an internal jumper that selects the default input level and input resistor pull-up or pull-down connections so that the amplifier shuts down with no input.