Intrinsically safe coupling circuit - has logic connecting one or all input control signals through to relay which controls outside machine

摘要

The intrinsically-safe control lines (2a-2n) and there is a intrinsically-safe control lines (2a-2n) and there is a circuit (6) to select logically individual signals or all input signals. These signals are passed through to a switch (7) (e.g. a relay) coupled to the output terminals. The output terminals are connected to the non-intrinsically-safe machine or a device (11, 12) being controlled. The logic circuit is set by a selector (8). Each control line has its own signalling lamp.