Safety switching circuit with at least one emergency stop switch

摘要

A safety circuit has at least one emergency stop switch (42) and operates to control the connection between load devices and a power supply. The switch is connected in series with the primary winding (44) of an electrical transformer (46), with the secondary windings (56,60) connected to the loads. A further secondary winding (64) provides a power supply (34) for an oscillator (36) that maintains an alternative supply for the primary and is protected against circuit faults.