SPD DIN-Rail Switching Power Supplies Carlo Gavazzi SPD DIN-Rail Switching Power Supplies are a broad range of power supplies from 5W to 960W output designed for demanding applications where dimensions are not an issue. The Carlo Gavazzi SPD DIN-Rail Switching Power Supplies feature devices from 5W to 480W with single-phase input, 100W devices with 1x bi-phase input, and 120W to 960W power supplies with 3-phase input. SPD power supplies provide DC OK output, power-factor correction, and parallel operation.