Product Description:

The 5121 DC servo amplifier is produced by Copley Controls and belongs to the DC Servo Amplifiers series. Designed for machine tools, robotics, and other motion systems, the module translates low-level velocity or torque commands into controlled motor current, giving automation designers a compact power stage for brushed or brushless DC actuators. Because it mounts without a heat sink, the package fits into compact equipment panels where the installation provides sufficient airflow. Its compact form also allows it to be placed close to the motor connections, which can help shorten power wiring within the machine.

It delivers a continuous output of 10 A and can supply short bursts of up to 20 A for acceleration or disturbance rejection. Motor current is regulated by a closed current loop with a bandwidth of 3 kHz, allowing the drive to follow rapid command changes with minimal phase lag. Pulse-width modulation operates at 25 kHz, keeping audible noise low and reducing current ripple across the armature inductance. The output stage presents only 0.2 Ω of resistance, so most of the DC bus energy reaches the load. Command sources see an input impedance of 94 kΩ at the analog reference port. Digital direction and enable lines are buffered by 10 kΩ logic inputs that switch at 2.5 V.

An overtemperature sensor trips at 70 °C, protecting the amplifier when internal heat rises beyond its operating limit. The DC bus is disconnected if the voltage exceeds 92 VDC or falls below 22 VDC. The reference terminal accepts commands within a range of ±20 V, providing compatibility with common ±10 V motion controllers while tolerating overrange signals. The amplifier supplies 5 mA at +15 V for sensor excitation and 250 mA at +5 V for encoder electronics. Its control logic draws only 2.5 W from the input supply. The board measures 3.82 × 6.57 × 1.37 inches, allowing installation in dense racks or equipment panels where available mounting space is limited.