Mitsubishi Electric MR-J3-40A1 Servo Amplifier

The Mitsubishi Electric MR-J3-40A1 servo amplifier is a 0.4 kW drive in the MELSERVO-J3 family that precisely controls speed, torque, and position of servo motors in automated machinery. Widely used in CNC machines, robotics, packaging equipment, pick-and-place systems, semiconductor equipment, and automated production lines, it supports maintenance teams and system integrators with repairs, retrofits, and replacements of legacy servo amplifiers. Key specs include 1-phase 100 VAC input (A1 variant), Sinusoidal PWM / current control, built-in dynamic brake and regenerative resistor (model dependent), encoder feedback up to 262,144 pulses per revolution, USB and RS-422/485 communications, and control modes for position, speed, and torque; protections for overcurrent, overvoltage, overload, encoder fault, and overspeed; operating temperature 0–55°C; cooling by fan or natural cooling depending on configuration; panel-mount design; weight approx. 2 lb. Common replacements include MR-J4-40A, MR-JE-40A, and MR-J3-40A.