Product Description:

The 412 is a DC motor servo amplifier produced by Copley Controls within the DC Servo Amplifiers series. The module conditions low-voltage control signals and delivers controlled current to permanent-magnet DC motors, allowing accurate velocity and torque regulation in pick-and-place stages, indexing tables, and other automated axes. By converting a reference command into a pulse-width-modulated output, it forms the power interface between motion controllers and electromechanical loads. Its compact board-level format fits inside distributed machine cabinets.

The power stage operates from 24–90 VDC, supplying up to 10 A continuously to the motor. For dynamic events, it can supply 20 A for 1 s before returning to nominal thermal limits. Current flow is controlled by a pulse-width-modulated bridge that switches at 25 kHz, and the amplifier’s current loop maintains a closed-loop bandwidth of 3 kHz so torque follows command steps with minimal delay. The complementary voltage-feedback path has a 200 Hz bandwidth, allowing stable operation with compliant loads. With a differential gain of 1.0:1, the analog reference is reproduced without scaling, while the PWM current scale is fixed at Ipeak divided by 6 V for simple calibration. Load inductances from 200 µH to 40 mH are accepted without additional damping components.

Control connections are compatible with digital and analog sources. The reference port withstands ±20 V and presents an impedance of 100 kΩ to minimize the load on upstream DACs. Direction, enable, and inhibit pins accept 0–24 V logic levels through internal 10 kΩ pull-ups tied to +5 V. These inputs change state at the 2.5 V threshold, so both open-collector and push-pull drivers can be used. Motor leads have an 0.2 Ω output path that limits conduction losses while providing accurate current sampling.