Brochure/Catalogue

Low power circuits with values below 30 V/10 mA are mainly used in
applications where signals has to be transmitted to control inputs, e.g. to
a PLC. Such low loads do not produce a sufficient arc at the contacts.
However, this arc has two important functions:
On the one hand, it ensures continuous cleaning of the contacts; on the other
hand, it can penetrate non-conductive foreign layers at the contacts. Such
foreign layers are usually created by oxidation or sulfidation of common contact
materials such as silver (Ag), silver-nickel (AgNi), or silver-tin oxide (AgSnO).
The foreign layers can increase the contact resistance after a short time to
such an extent that reliable switching of low loads is no longer possible.
For these reasons, gold (Au) is used as the contact material for relays
switching small loads. It has proven itself due to its low and constant
contact resistance and its resistance to ambient air containing sulphur.
Switching of very low power circuits
Relay for forwarding control signals
A.14 2737920000
Selection guide
A
Relay for forwarding control signals