How the intermediate relay is self-locking
Self-locking relay principle is the coil power through the switch after the suction, the auxiliary contact at the same time connected to provide the coil of the pull power, switch off after the relay self-locking
Self-locking in the software set, called software self-locking SB: button
KM: relay
Press the button is KM power, relay KM normally open electric shock closed, to achieve the relay self-locking.
Brief description of the principle:
1, when the press QA, QA power, the middle relay ZJ coil power, so that the middle relay pull. At this time the middle of the relay normally open contact also pull up. At this time, although the QA has been disconnected, but the current has been closed through the ZJ often open point, flow to the middle of the relay coil, leaving the middle relay still pull, which played a role in self-locking.
2, when you need to stop using, as long as the TA button, the middle of the relay coil immediately lost the voltage and release. At this time the middle of the relay is often open contact ZJ will be disconnected, self-locking effect will be eliminated.
