Relay demagnetization

[DR350SE]

My question is ,
the relaise voltage of a DC-relay is +/- 10 % of the nominal voltage .
example : Unom.=12V >>>>Urelaise=1.5V(relay contact goes open)

Temperature influence +/- 30%

But what is the influence on long term (after years) of the relaise voltage ?
(demagnetiszation of the relay)

 

[Kral]

DR350SE,
Ordinary armature style relays do not use permanent magnets, so de-magnetization over time is not an issue. Armature relays use magnetic materials with low coercivity and remanence so that they will not become permanently magnetized under the influence of a magnetic field. It is possible that the core could become permanently magnetized to a small degree after repeated use. In this case, the release voltage would decrease over time, since there would be a residual magnetic field present after the excitation voltage is removed. I have never seen any manufactur data on this phenomenon. I believe that this effect would be very small, since manufacturers deliberately use magnetic materials with very loww remanence and coercivity.
.
Reed relays do use permanent magnets, so it is possible that, over time, the coercivity and remanence of the permanent magnet could decrease. I have never seen any manufacturer data on this phenomenon.
Regards,
Kral

 

[DR350SE]

Kral , thank you .

(I've also asked this to a relay manufacturer and they also told me that the Unom may only decrease to 1/2 Unom for normal operation )