The structure and working principle of universal change-over switch

Universal switch ( Text symbols SA) Role: it is used for infrequent on and off the circuit, realize the power and load, is a kind of file type, electrical control circuit of the main. Switch by the rotating shaft, CAM, contact, positioning, screw rod and a handle, etc. When turn the lever to different gear, shaft with the CAM rotates, make some contacts through, others contact disconnect. It has a long service life, the use of the advantages of simple structure and reliable, suitable for ac 50 hz, 380 v, dc 220 v and below the power supply, introducing directly below 5 kw small capacity motor starts, the forward and inversion of control of the motor and the lighting control circuit, but the transformation of the number should not be more than an hour 15 ~ 20 times. Universal switch symbol universal switch symbol above shows the switch gear, on state, the contact number and table are marked 'x' contact connect, otherwise is disconnected, the wiring table to draw the graphic symbol. Specific illustration is: with a dotted line and the location of the operating handles with presence of '. , it means when operating handle is in the position, the contact is in the closed state; If the position did not draw on the dotted line '. ', said the contact is in the open state.