STK-W-3 microcomputer controller peripheral circuit

The peripheral circuit of the STK-W-3 microcomputer controller is shown in Figure 7-12. The   microcomputer controller outputs four sets of control signals in the form of relay contacts: open, close, overspeed, and close. The microcomputer sends out a "turn on" signal, and the relay KAi is turned on; the microcomputer sends out a "turn off" signal, and the relay KAz is turned on; when the machine frequency exceeds the specified value, the microcomputer sends out an "overspeed" signal, and the relay KA is turned on. Pull-in, which acts on the main switch to open. When the microcomputer sends a "close" signal, relay KA4 pulls-in. The overspeed signal can act on the main switch to open, and can also act on the deflector action.