Protection of relay contacts

Protection of relay contacts

   (1) When the contact disconnects the inductive load circuit, the energy stored in the load must be consumed through the ignition of the arc. In order to eliminate and reduce the harm of the arc when the inductive load is disconnected, extend the service life of the contact, eliminate or reduce the relay For electromagnetic interference and damage to related sensitive circuits, arc suppression protection measures are usually adopted.

    Common contact protection circuits include: connecting a resistor or RC circuit in parallel to an inductive load, or a diode in parallel.

   (2) The output and input of the relay should be avoided to be collinear or connected as much as possible, because when the coil is de-excited, the back EMF on the coil will be added to the contact, which will increase the disconnection voltage of the contact and also interfere with Circuit.