Teknic, Inc.

Servo Drives

In Teknic SSt-series Servo Drives, a high-speed DSP control processor controls all of the feedback loops: position, velocity and actual torque. Torque is actively measured and controlled, with losses in the motor effectively minimized. The operation is truly all-digital: the motor currents are converted directly into digital format for the DSP and the outputs to the motor are digital PWM pulse streams—no drift- or noise-prone analog processing is used whatsoever.

The dedicated DSP processor within the SSt servo drive knows, at all times: the state of the position/velocity compensator, the state of the motor's magnetic field, the output voltages of the amplifier, the limit switch inputs, the RMS current in the motor, and numerous other variables. The SSt's proprietary control algorithms are specifically designed to make good use of all this information. The result is superior performance not only in the standard benchmarks (bandwidth, settling time, tracking accuracy), but also in the subjective benchmarks such as quiet jitter-free operation, virtual elimination of overshoot, reduction of torque "chatter", and more. In addition, the DSP's knowledge of the entire state of the servo system enables several unique features. Thousands of hours of computer simulation and experimentation have yielded, among other features: Adaptive Inertia Matching Technology (IMT), Hard-stop homing, fuzzy MoveDone signal false trigger suppression, and continuous current sensor calibration. For more information on these unique features, see the Systems Information section.

SSt servo systems deliver the best price/performance in position mode (digital step & direction input) where the DSP controls all servo loops. However, the SSt servo drive is also available in a ±10V analog interface version so you can get the benefits of closed-loop vector torque control, true RMS limiting, and sinewave commutation (among others) using a traditional servo control board.

The following table of servo drives represents products which, while no longer available for new designs, will continue to be sold and supported on existing designs for the foreseeable future.

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