✏️Song Chuan ( is one of the key suppliers of relays and contactors. ▍HVDC Architecture Drives Value Growth As PSU power ratings scale from 3.3–5.5 kW up to 8–12 kW, and even reach 24 kW, operating voltages are likewise advancing toward 400 VDC and 800 VDC. Consequently, specifications for high-voltage DC contactors and relays—particularly in arc suppression, dielectric strength, and footprint—have become significantly more demanding. While consolidation into higher-density power shelves may reduce the total unit count per rack, the technical complexity drives a substantial increase in average selling price (ASP), resulting in a net positive expansion in total rack content value. -- *What is a relay ? A relay is one of those components people rarely notice until they begin working around electrical systems regularly. Then suddenly it appears everywhere. At its core, a relay is simply an electrically operated switch. A small current energises a coil inside the device, which then moves internal contacts to open or close another circuit. This is the basic idea. Nothing overly complicated. *What is a contactor ? A contactor does something very similar to a relay, but under much tougher electrical conditions. Instead of switching small control signals, contactors are usually responsible for handling equipment that consumes substantial current- motors, industrial pumps, compressors, large ventilation systems, production machinery, and heavy lighting loads.