Regarding power supply and distribution issues
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Today I saw that flame detectors, which are also digital devices, still require power supply, while NC, NO, and COM switches do not need such a supply. In what situations is the difference between power supply and power distribution utilized?
This post was last edited by Duanmu Yun on 2017-5-24 at 17:54. NC NO COM refers to dry contacts or passive contacts, which only indicate whether a circuit is open or closed; therefore, no power is supplied. Flame detectors contain electrical components for detection and signal transmission, so they require power supply. Whether power is supplied or not has nothing to do with digital or analog signals; it depends solely on whether the component itself consumes power.