Quick question regarding low voltage signal relays, do they degrade just sitting around new and unused? I have several NEC MR62 24V which in my case are the exact replacement model (nice for aesthetic reasons) there is a stamp on them 47/7 that makes me think 47th week of 2007 (or maybe 1997 or 1987) if that's what the numbers mean then they're at least 15ys/o.
It’s for an Onix OA21 hifi amplifier, input channel switching not speaker protection, I’ve read it’s a good idea to replace relays after about 20 years as the contacts weaken and corrode, the builder actually posted on DIYA that they should be replaced when doing a full service. Specs state contacts are gold over silver alloy and it's potted and sealed so I don't really see how they would corrode just sitting around even after many years, on the other hand the springs and coils inside might just be seized up or corroded. It's a very hard PCB to pull out IOW this is something I only want to do once while I'm recapping it.
A new set of equivalent Omrons would cost me $10 so not a big deal but I really hate to not use stuff I have on hand plus aesthetically it would look right, the NEC's are pink 🙂
It’s for an Onix OA21 hifi amplifier, input channel switching not speaker protection, I’ve read it’s a good idea to replace relays after about 20 years as the contacts weaken and corrode, the builder actually posted on DIYA that they should be replaced when doing a full service. Specs state contacts are gold over silver alloy and it's potted and sealed so I don't really see how they would corrode just sitting around even after many years, on the other hand the springs and coils inside might just be seized up or corroded. It's a very hard PCB to pull out IOW this is something I only want to do once while I'm recapping it.
A new set of equivalent Omrons would cost me $10 so not a big deal but I really hate to not use stuff I have on hand plus aesthetically it would look right, the NEC's are pink 🙂
Signal contacts (unwetted by mercury or a small DC current) can develop a parasitic insulating layer, even when coated with noble metals or in an inert atmosphere.
I think the problem has largely been solved, thanks to advances in the micro-metallurgy amongst other factors.
In older contact systems, the coating layer slowly alloyed/migrated into the base metal and ended up with alloys having unfavourable conduction/contact properties.
The issue seems to be solved now, but it is necessary to select the proper contact material option for the application you have in mind.
I think the problem has largely been solved, thanks to advances in the micro-metallurgy amongst other factors.
In older contact systems, the coating layer slowly alloyed/migrated into the base metal and ended up with alloys having unfavourable conduction/contact properties.
The issue seems to be solved now, but it is necessary to select the proper contact material option for the application you have in mind.