REF542plus 1VCR007346 G0012 electric actuator in the control process can not obtain some of its own characteristics of parameters, so that the control accuracy and reliability are not high, the input signal is only a kind of, such as current or resistance, and then will detect the signal and the input signal to compare the control signals obtained to the drive circuit, in order to control the actuator’s displacement output; Although some electric actuators have alarm circuits, they do not adopt chain protection measures, which makes them unsafe in the alarm state, and thus such servo amplified majority-controlled electric actuators cannot be applied to some occasions with high requirements for precision, reliability and stability.

REF542plus 1VCR007346 G0012 electric actuators generally provide five signal points: one analogue signal for feedback of the position signal of the electric actuator; two switching contact input signals for feedback of the electric actuator of the two limits of the alarm signal; in addition, there are two forward and reverse coils of the drive interface for connecting the power devices, such as solid-state relays In addition, there are two forward and reverse coil drive interfaces for connecting power devices, such as solid state relays or thyristors, so that the SST or PAT module can drive solid state relays or thyristors through the switching output signals to drive the electric actuator forward or reverse.

REF542plus 1VCR007346 G0012 In order to facilitate the implementation of the project, the valve position feedback signal line, the power supply line and the switching output signal line are concentrated in the same cable, and the crosstalk between the signal lines is serious, so the hardware of the PAT module must be strictly designed in terms of isolation, anti-jamming and electromagnetic compatibility. PAT module design adopts photoelectric isolation technology and electromagnetic isolation technology, analogue processing circuits are isolated separately, and the switching part is isolated uniformly. The switching output part is then isolated from weak and strong power by solid state relay, effectively overcoming the interference between different signals.