Transient Suppressor VaristorVellemanVaristor for Velleman K8090 and VM206 boards. Fit where inductive loads are connected to the relay output. Prevents relay contacts from sticking and damage due to arcing.Electronics > Circuit Components > Semiconductors > DiodesVDR300VDR30054103292525640.60Quasar Electronics Limitedhttps://quasarelectronics.co.uk/Item/velleman-vdr300-transient-suppressor-varistor
Varistor transient suppessor for Velleman K8090, VM206 and other relay boards used to switch inductive loads. They help to prolong the life of the relays contacts by reducing damage and sticking due to arcing.
Simply fit across relay contacts C and NO (and/or C and NC if you use those).