EM-D-30
by Vickers
The EM-D-30 is an amplifier board manufactured by Vickers for the Vickers Amplifier Boards series. This plug-in module conditions low-level control signals and supplies regulated coil current to electro-hydraulic valves, acting as the intermediary between PLC commands and proportional actuators in automated machinery.
The board length is 127.0 mm, giving it a compact footprint in rack assemblies, and its closed-loop bandwidth reaches 6 kHz at –3 dB, allowing fast valve response. The differential input will tolerate up to 10 V DC without damage. Faults are reported through an opto-coupled alarm output that isolates external logic. The power stage can deliver 600 mA into a 20 Ω load, with a supply-related drift of ±0.001 mA/V; thermal drift is limited to ±0.4 mA/°C, so commanded null current remains stable across cabinet temperature changes.
Upstream of the power stage, the voltage amplifier provides a 6 V reference capable of 5 mA; its 24-hour stability is ±0.005 V DC, the warm-up shift is ±0.004 V DC, and the temperature coefficient is ±0.0002 V/V. Supply sensitivity is contained to ±0.0001 V/V, minimizing gain error from bus ripple. The pre-amplifier outputs 2 mA at a controlled 10 V DC level, establishing a fixed headroom for the voltage stage. Warm-up drift at null is capped at ±0.1 mA, preventing bias creep on start-up. For external monitoring, the voltage amplifier places a stable 6 V DC signal on a dedicated test pin while the opto-coupled alarm path remains unaffected.
